diff --git a/docs/source/distributions/configuration.md b/docs/source/distributions/configuration.md
index 4bc9b37e4..1b50ee712 100644
--- a/docs/source/distributions/configuration.md
+++ b/docs/source/distributions/configuration.md
@@ -18,7 +18,7 @@ providers:
   - provider_id: ollama
     provider_type: remote::ollama
     config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
+      url: ${env.OLLAMA_URL:=http://localhost:11434}
   vector_io:
   - provider_id: faiss
     provider_type: inline::faiss
@@ -26,7 +26,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -38,7 +38,7 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/agents_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -46,7 +46,7 @@ providers:
 metadata_store:
   namespace: null
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/registry.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
@@ -85,7 +85,7 @@ providers:
     # config is a dictionary that contains the configuration for the provider.
     # in this case, the configuration is the url of the ollama server
     config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
+      url: ${env.OLLAMA_URL:=http://localhost:11434}
 ```
 A few things to note:
 - A _provider instance_ is identified with an (id, type, configuration) triplet.
@@ -94,6 +94,95 @@ A few things to note:
 - The configuration dictionary is provider-specific.
 - Notice that configuration can reference environment variables (with default values), which are expanded at runtime. When you run a stack server (via docker or via `llama stack run`), you can specify `--env OLLAMA_URL=http://my-server:11434` to override the default value.
 
+### Environment Variable Substitution
+
+Llama Stack supports environment variable substitution in configuration values using the
+`${env.VARIABLE_NAME}` syntax. This allows you to externalize configuration values and provide
+different settings for different environments. The syntax is inspired by [bash parameter expansion](https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html)
+and follows similar patterns.
+
+#### Basic Syntax
+
+The basic syntax for environment variable substitution is:
+
+```yaml
+config:
+  api_key: ${env.API_KEY}
+  url: ${env.SERVICE_URL}
+```
+
+If the environment variable is not set, the server will raise an error during startup.
+
+#### Default Values
+
+You can provide default values using the `:=` operator:
+
+```yaml
+config:
+  url: ${env.OLLAMA_URL:=http://localhost:11434}
+  port: ${env.PORT:=8321}
+  timeout: ${env.TIMEOUT:=60}
+```
+
+If the environment variable is not set, the default value `http://localhost:11434` will be used.
+Empty defaults are not allowed so `url: ${env.OLLAMA_URL:=}` will raise an error if the environment variable is not set.
+
+#### Conditional Values
+
+You can use the `:+` operator to provide a value only when the environment variable is set:
+
+```yaml
+config:
+  # Only include this field if ENVIRONMENT is set
+  environment: ${env.ENVIRONMENT:+production}
+```
+
+If the environment variable is set, the value after `:+` will be used. If it's not set, the field
+will be omitted with a `None` value.
+So `${env.ENVIRONMENT:+}` is supported, it means that the field will be omitted if the environment
+variable is not set. It can be used to make a field optional and then enabled at runtime when desired.
+
+#### Examples
+
+Here are some common patterns:
+
+```yaml
+# Required environment variable (will error if not set)
+api_key: ${env.OPENAI_API_KEY}
+
+# Optional with default
+base_url: ${env.API_BASE_URL:=https://api.openai.com/v1}
+
+# Conditional field
+debug_mode: ${env.DEBUG:+true}
+
+# Optional field that becomes None if not set
+optional_token: ${env.OPTIONAL_TOKEN:+}
+```
+
+#### Runtime Override
+
+You can override environment variables at runtime when starting the server:
+
+```bash
+# Override specific environment variables
+llama stack run --config run.yaml --env API_KEY=sk-123 --env BASE_URL=https://custom-api.com
+
+# Or set them in your shell
+export API_KEY=sk-123
+export BASE_URL=https://custom-api.com
+llama stack run --config run.yaml
+```
+
+#### Type Safety
+
+The environment variable substitution system is type-safe:
+
+- String values remain strings
+- Empty defaults (`${env.VAR:+}`) are converted to `None` for fields that accept `str | None`
+- Numeric defaults are properly typed (e.g., `${env.PORT:=8321}` becomes an integer)
+- Boolean defaults work correctly (e.g., `${env.DEBUG:=false}` becomes a boolean)
+
 ## Resources
 
 Finally, let's look at the `models` section:
@@ -152,7 +241,7 @@ server:
     config:
       jwks:
         uri: "https://kubernetes.default.svc:8443/openid/v1/jwks"
-        token: "${env.TOKEN:}"
+        token: "${env.TOKEN:+}"
         key_recheck_period: 3600
       tls_cafile: "/path/to/ca.crt"
       issuer: "https://kubernetes.default.svc"
@@ -396,12 +485,12 @@ providers:
   - provider_id: vllm-0
     provider_type: remote::vllm
     config:
-      url: ${env.VLLM_URL:http://localhost:8000}
+      url: ${env.VLLM_URL:=http://localhost:8000}
   # this vLLM server serves the llama-guard model (e.g., llama-guard:3b)
   - provider_id: vllm-1
     provider_type: remote::vllm
     config:
-      url: ${env.SAFETY_VLLM_URL:http://localhost:8001}
+      url: ${env.SAFETY_VLLM_URL:=http://localhost:8001}
 ...
 models:
 - metadata: {}
diff --git a/docs/source/distributions/k8s/stack-configmap.yaml b/docs/source/distributions/k8s/stack-configmap.yaml
index fa7bacd8f..0a08bca03 100644
--- a/docs/source/distributions/k8s/stack-configmap.yaml
+++ b/docs/source/distributions/k8s/stack-configmap.yaml
@@ -15,10 +15,10 @@ data:
       - provider_id: vllm-inference
         provider_type: remote::vllm
         config:
-          url: ${env.VLLM_URL:http://localhost:8000/v1}
-          max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-          api_token: ${env.VLLM_API_TOKEN:fake}
-          tls_verify: ${env.VLLM_TLS_VERIFY:true}
+          url: ${env.VLLM_URL:=http://localhost:8000/v1}
+          max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+          api_token: ${env.VLLM_API_TOKEN:=fake}
+          tls_verify: ${env.VLLM_TLS_VERIFY:=true}
       - provider_id: vllm-safety
         provider_type: remote::vllm
         config:
@@ -30,10 +30,10 @@ data:
         provider_type: inline::sentence-transformers
         config: {}
       vector_io:
-      - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+      - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
         provider_type: remote::chromadb
         config:
-          url: ${env.CHROMADB_URL:}
+          url: ${env.CHROMADB_URL:+}
       safety:
       - provider_id: llama-guard
         provider_type: inline::llama-guard
@@ -45,34 +45,34 @@ data:
         config:
           persistence_store:
             type: postgres
-            host: ${env.POSTGRES_HOST:localhost}
-            port: ${env.POSTGRES_PORT:5432}
-            db: ${env.POSTGRES_DB:llamastack}
+            host: ${env.POSTGRES_HOST:=localhost}
+            port: ${env.POSTGRES_PORT:=5432}
+            db: ${env.POSTGRES_DB:=llamastack}
             user: ${env.POSTGRES_USER:llamastack}
-            password: ${env.POSTGRES_PASSWORD:llamastack}
+            password: ${env.POSTGRES_PASSWORD:=llamastack}
           responses_store:
             type: postgres
-            host: ${env.POSTGRES_HOST:localhost}
-            port: ${env.POSTGRES_PORT:5432}
-            db: ${env.POSTGRES_DB:llamastack}
-            user: ${env.POSTGRES_USER:llamastack}
-            password: ${env.POSTGRES_PASSWORD:llamastack}
+            host: ${env.POSTGRES_HOST:=localhost}
+            port: ${env.POSTGRES_PORT:=5432}
+            db: ${env.POSTGRES_DB:=llamastack}
+            user: ${env.POSTGRES_USER:=llamastack}
+            password: ${env.POSTGRES_PASSWORD:=llamastack}
       telemetry:
       - provider_id: meta-reference
         provider_type: inline::meta-reference
         config:
-          service_name: ${env.OTEL_SERVICE_NAME:}
+          service_name: ${env.OTEL_SERVICE_NAME:+}
           sinks: ${env.TELEMETRY_SINKS:console}
       tool_runtime:
       - provider_id: brave-search
         provider_type: remote::brave-search
         config:
-          api_key: ${env.BRAVE_SEARCH_API_KEY:}
+          api_key: ${env.BRAVE_SEARCH_API_KEY:+}
           max_results: 3
       - provider_id: tavily-search
         provider_type: remote::tavily-search
         config:
-          api_key: ${env.TAVILY_SEARCH_API_KEY:}
+          api_key: ${env.TAVILY_SEARCH_API_KEY:+}
           max_results: 3
       - provider_id: rag-runtime
         provider_type: inline::rag-runtime
@@ -82,19 +82,19 @@ data:
         config: {}
     metadata_store:
       type: postgres
-      host: ${env.POSTGRES_HOST:localhost}
-      port: ${env.POSTGRES_PORT:5432}
-      db: ${env.POSTGRES_DB:llamastack}
-      user: ${env.POSTGRES_USER:llamastack}
-      password: ${env.POSTGRES_PASSWORD:llamastack}
+      host: ${env.POSTGRES_HOST:=localhost}
+      port: ${env.POSTGRES_PORT:=5432}
+      db: ${env.POSTGRES_DB:=llamastack}
+      user: ${env.POSTGRES_USER:=llamastack}
+      password: ${env.POSTGRES_PASSWORD:=llamastack}
       table_name: llamastack_kvstore
     inference_store:
       type: postgres
-      host: ${env.POSTGRES_HOST:localhost}
-      port: ${env.POSTGRES_PORT:5432}
-      db: ${env.POSTGRES_DB:llamastack}
-      user: ${env.POSTGRES_USER:llamastack}
-      password: ${env.POSTGRES_PASSWORD:llamastack}
+      host: ${env.POSTGRES_HOST:=localhost}
+      port: ${env.POSTGRES_PORT:=5432}
+      db: ${env.POSTGRES_DB:=llamastack}
+      user: ${env.POSTGRES_USER:=llamastack}
+      password: ${env.POSTGRES_PASSWORD:=llamastack}
     models:
     - metadata:
         embedding_dimension: 384
@@ -106,11 +106,11 @@ data:
       provider_id: vllm-inference
       model_type: llm
     - metadata: {}
-      model_id: ${env.SAFETY_MODEL:meta-llama/Llama-Guard-3-1B}
+      model_id: ${env.SAFETY_MODEL:=meta-llama/Llama-Guard-3-1B}
       provider_id: vllm-safety
       model_type: llm
     shields:
-    - shield_id: ${env.SAFETY_MODEL:meta-llama/Llama-Guard-3-1B}
+    - shield_id: ${env.SAFETY_MODEL:=meta-llama/Llama-Guard-3-1B}
     vector_dbs: []
     datasets: []
     scoring_fns: []
diff --git a/docs/source/distributions/k8s/stack_run_config.yaml b/docs/source/distributions/k8s/stack_run_config.yaml
index 8e2773dd1..5ac08134c 100644
--- a/docs/source/distributions/k8s/stack_run_config.yaml
+++ b/docs/source/distributions/k8s/stack_run_config.yaml
@@ -12,25 +12,25 @@ providers:
   - provider_id: vllm-inference
     provider_type: remote::vllm
     config:
-      url: ${env.VLLM_URL:http://localhost:8000/v1}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      url: ${env.VLLM_URL:=http://localhost:8000/v1}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: vllm-safety
     provider_type: remote::vllm
     config:
-      url: ${env.VLLM_SAFETY_URL:http://localhost:8000/v1}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      url: ${env.VLLM_SAFETY_URL:=http://localhost:8000/v1}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
   vector_io:
-  - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+  - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
     provider_type: remote::chromadb
     config:
-      url: ${env.CHROMADB_URL:}
+      url: ${env.CHROMADB_URL:+}
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -42,34 +42,34 @@ providers:
     config:
       persistence_store:
         type: postgres
-        host: ${env.POSTGRES_HOST:localhost}
-        port: ${env.POSTGRES_PORT:5432}
-        db: ${env.POSTGRES_DB:llamastack}
-        user: ${env.POSTGRES_USER:llamastack}
-        password: ${env.POSTGRES_PASSWORD:llamastack}
+        host: ${env.POSTGRES_HOST:=localhost}
+        port: ${env.POSTGRES_PORT:=5432}
+        db: ${env.POSTGRES_DB:=llamastack}
+        user: ${env.POSTGRES_USER:=llamastack}
+        password: ${env.POSTGRES_PASSWORD:=llamastack}
       responses_store:
         type: postgres
-        host: ${env.POSTGRES_HOST:localhost}
-        port: ${env.POSTGRES_PORT:5432}
-        db: ${env.POSTGRES_DB:llamastack}
-        user: ${env.POSTGRES_USER:llamastack}
-        password: ${env.POSTGRES_PASSWORD:llamastack}
+        host: ${env.POSTGRES_HOST:=localhost}
+        port: ${env.POSTGRES_PORT:=5432}
+        db: ${env.POSTGRES_DB:=llamastack}
+        user: ${env.POSTGRES_USER:=llamastack}
+        password: ${env.POSTGRES_PASSWORD:=llamastack}
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: ${env.OTEL_SERVICE_NAME:}
-      sinks: ${env.TELEMETRY_SINKS:console}
+      service_name: ${env.OTEL_SERVICE_NAME:+console}
+      sinks: ${env.TELEMETRY_SINKS:+console}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -79,19 +79,19 @@ providers:
     config: {}
 metadata_store:
   type: postgres
-  host: ${env.POSTGRES_HOST:localhost}
-  port: ${env.POSTGRES_PORT:5432}
-  db: ${env.POSTGRES_DB:llamastack}
-  user: ${env.POSTGRES_USER:llamastack}
-  password: ${env.POSTGRES_PASSWORD:llamastack}
+  host: ${env.POSTGRES_HOST:=localhost}
+  port: ${env.POSTGRES_PORT:=5432}
+  db: ${env.POSTGRES_DB:=llamastack}
+  user: ${env.POSTGRES_USER:=llamastack}
+  password: ${env.POSTGRES_PASSWORD:=llamastack}
   table_name: llamastack_kvstore
 inference_store:
   type: postgres
-  host: ${env.POSTGRES_HOST:localhost}
-  port: ${env.POSTGRES_PORT:5432}
-  db: ${env.POSTGRES_DB:llamastack}
-  user: ${env.POSTGRES_USER:llamastack}
-  password: ${env.POSTGRES_PASSWORD:llamastack}
+  host: ${env.POSTGRES_HOST:=localhost}
+  port: ${env.POSTGRES_PORT:=5432}
+  db: ${env.POSTGRES_DB:=llamastack}
+  user: ${env.POSTGRES_USER:=llamastack}
+  password: ${env.POSTGRES_PASSWORD:=llamastack}
 models:
 - metadata:
     embedding_dimension: 384
@@ -103,11 +103,11 @@ models:
   provider_id: vllm-inference
   model_type: llm
 - metadata: {}
-  model_id: ${env.SAFETY_MODEL:meta-llama/Llama-Guard-3-1B}
+  model_id: ${env.SAFETY_MODEL:=meta-llama/Llama-Guard-3-1B}
   provider_id: vllm-safety
   model_type: llm
 shields:
-- shield_id: ${env.SAFETY_MODEL:meta-llama/Llama-Guard-3-1B}
+- shield_id: ${env.SAFETY_MODEL:=meta-llama/Llama-Guard-3-1B}
 vector_dbs: []
 datasets: []
 scoring_fns: []
diff --git a/llama_stack/distribution/datatypes.py b/llama_stack/distribution/datatypes.py
index 5324e4c29..e07da001e 100644
--- a/llama_stack/distribution/datatypes.py
+++ b/llama_stack/distribution/datatypes.py
@@ -29,8 +29,8 @@ from llama_stack.providers.datatypes import Api, ProviderSpec
 from llama_stack.providers.utils.kvstore.config import KVStoreConfig, SqliteKVStoreConfig
 from llama_stack.providers.utils.sqlstore.sqlstore import SqlStoreConfig
 
-LLAMA_STACK_BUILD_CONFIG_VERSION = "2"
-LLAMA_STACK_RUN_CONFIG_VERSION = "2"
+LLAMA_STACK_BUILD_CONFIG_VERSION = 2
+LLAMA_STACK_RUN_CONFIG_VERSION = 2
 
 
 RoutingKey = str | list[str]
@@ -229,7 +229,7 @@ class ServerConfig(BaseModel):
 
 
 class StackRunConfig(BaseModel):
-    version: str = LLAMA_STACK_RUN_CONFIG_VERSION
+    version: int = LLAMA_STACK_RUN_CONFIG_VERSION
 
     image_name: str = Field(
         ...,
@@ -300,7 +300,7 @@ a default SQLite store will be used.""",
 
 
 class BuildConfig(BaseModel):
-    version: str = LLAMA_STACK_BUILD_CONFIG_VERSION
+    version: int = LLAMA_STACK_BUILD_CONFIG_VERSION
 
     distribution_spec: DistributionSpec = Field(description="The distribution spec to build including API providers. ")
     image_type: str = Field(
diff --git a/llama_stack/distribution/stack.py b/llama_stack/distribution/stack.py
index b33b0d3f7..c86880669 100644
--- a/llama_stack/distribution/stack.py
+++ b/llama_stack/distribution/stack.py
@@ -127,7 +127,12 @@ class EnvVarError(Exception):
     def __init__(self, var_name: str, path: str = ""):
         self.var_name = var_name
         self.path = path
-        super().__init__(f"Environment variable '{var_name}' not set or empty{f' at {path}' if path else ''}")
+        super().__init__(
+            f"Environment variable '{var_name}' not set or empty {f'at {path}' if path else ''}. "
+            f"Use ${{env.{var_name}:=default_value}} to provide a default value, "
+            f"${{env.{var_name}:+value_if_set}} to make the field conditional, "
+            f"or ensure the environment variable is set."
+        )
 
 
 def replace_env_vars(config: Any, path: str = "") -> Any:
@@ -150,25 +155,27 @@ def replace_env_vars(config: Any, path: str = "") -> Any:
         return result
 
     elif isinstance(config, str):
-        # Updated pattern to support both default values (:) and conditional values (+)
-        pattern = r"\${env\.([A-Z0-9_]+)(?:([:\+])([^}]*))?}"
+        # Pattern supports bash-like syntax: := for default and :+ for conditional and a optional value
+        pattern = r"\${env\.([A-Z0-9_]+)(?::([=+])([^}]*))?}"
 
-        def get_env_var(match):
+        def get_env_var(match: re.Match):
             env_var = match.group(1)
-            operator = match.group(2)  # ':' for default, '+' for conditional
+            operator = match.group(2)  # '=' for default, '+' for conditional
             value_expr = match.group(3)
 
             env_value = os.environ.get(env_var)
 
-            if operator == ":":  # Default value syntax: ${env.FOO:default}
+            if operator == "=":  # Default value syntax: ${env.FOO:=default}
                 if not env_value:
-                    if value_expr is None:
+                    # value_expr returns empty string (not None) when not matched
+                    # This means ${env.FOO:=} is an error
+                    if value_expr == "":
                         raise EnvVarError(env_var, path)
                     else:
                         value = value_expr
                 else:
                     value = env_value
-            elif operator == "+":  # Conditional value syntax: ${env.FOO+value_if_set}
+            elif operator == "+":  # Conditional value syntax: ${env.FOO:+value_if_set}
                 if env_value:
                     value = value_expr
                 else:
@@ -183,13 +190,42 @@ def replace_env_vars(config: Any, path: str = "") -> Any:
             return os.path.expanduser(value)
 
         try:
-            return re.sub(pattern, get_env_var, config)
+            result = re.sub(pattern, get_env_var, config)
+            return _convert_string_to_proper_type(result)
         except EnvVarError as e:
             raise EnvVarError(e.var_name, e.path) from None
 
     return config
 
 
+def _convert_string_to_proper_type(value: str) -> Any:
+    # This might be tricky depending on what the config type is, if  'str | None' we are
+    # good, if 'str' we need to keep the empty string... 'str | None' is more common and
+    # providers config should be typed this way.
+    # TODO: we could try to load the config class and see if the config has a field with type 'str | None'
+    # and then convert the empty string to None or not
+    if value == "":
+        return None
+
+    lowered = value.lower()
+    if lowered == "true":
+        return True
+    elif lowered == "false":
+        return False
+
+    try:
+        return int(value)
+    except ValueError:
+        pass
+
+    try:
+        return float(value)
+    except ValueError:
+        pass
+
+    return value
+
+
 def validate_env_pair(env_pair: str) -> tuple[str, str]:
     """Validate and split an environment variable key-value pair."""
     try:
diff --git a/llama_stack/providers/inline/files/localfs/config.py b/llama_stack/providers/inline/files/localfs/config.py
index 757a70742..6c767af8f 100644
--- a/llama_stack/providers/inline/files/localfs/config.py
+++ b/llama_stack/providers/inline/files/localfs/config.py
@@ -23,7 +23,7 @@ class LocalfsFilesImplConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str) -> dict[str, Any]:
         return {
-            "storage_dir": "${env.FILES_STORAGE_DIR:" + __distro_dir__ + "/files}",
+            "storage_dir": "${env.FILES_STORAGE_DIR:=" + __distro_dir__ + "/files}",
             "metadata_store": SqliteSqlStoreConfig.sample_run_config(
                 __distro_dir__=__distro_dir__,
                 db_name="files_metadata.db",
diff --git a/llama_stack/providers/inline/inference/meta_reference/config.py b/llama_stack/providers/inline/inference/meta_reference/config.py
index 7bc961443..9556b026a 100644
--- a/llama_stack/providers/inline/inference/meta_reference/config.py
+++ b/llama_stack/providers/inline/inference/meta_reference/config.py
@@ -49,11 +49,11 @@ class MetaReferenceInferenceConfig(BaseModel):
     def sample_run_config(
         cls,
         model: str = "Llama3.2-3B-Instruct",
-        checkpoint_dir: str = "${env.CHECKPOINT_DIR:null}",
-        quantization_type: str = "${env.QUANTIZATION_TYPE:bf16}",
-        model_parallel_size: str = "${env.MODEL_PARALLEL_SIZE:0}",
-        max_batch_size: str = "${env.MAX_BATCH_SIZE:1}",
-        max_seq_len: str = "${env.MAX_SEQ_LEN:4096}",
+        checkpoint_dir: str = "${env.CHECKPOINT_DIR:=null}",
+        quantization_type: str = "${env.QUANTIZATION_TYPE:=bf16}",
+        model_parallel_size: str = "${env.MODEL_PARALLEL_SIZE:=0}",
+        max_batch_size: str = "${env.MAX_BATCH_SIZE:=1}",
+        max_seq_len: str = "${env.MAX_SEQ_LEN:=4096}",
         **kwargs,
     ) -> dict[str, Any]:
         return {
diff --git a/llama_stack/providers/inline/inference/vllm/config.py b/llama_stack/providers/inline/inference/vllm/config.py
index ce8743c74..660ef206b 100644
--- a/llama_stack/providers/inline/inference/vllm/config.py
+++ b/llama_stack/providers/inline/inference/vllm/config.py
@@ -44,10 +44,10 @@ class VLLMConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs: Any) -> dict[str, Any]:
         return {
-            "tensor_parallel_size": "${env.TENSOR_PARALLEL_SIZE:1}",
-            "max_tokens": "${env.MAX_TOKENS:4096}",
-            "max_model_len": "${env.MAX_MODEL_LEN:4096}",
-            "max_num_seqs": "${env.MAX_NUM_SEQS:4}",
-            "enforce_eager": "${env.ENFORCE_EAGER:False}",
-            "gpu_memory_utilization": "${env.GPU_MEMORY_UTILIZATION:0.3}",
+            "tensor_parallel_size": "${env.TENSOR_PARALLEL_SIZE:=1}",
+            "max_tokens": "${env.MAX_TOKENS:=4096}",
+            "max_model_len": "${env.MAX_MODEL_LEN:=4096}",
+            "max_num_seqs": "${env.MAX_NUM_SEQS:=4}",
+            "enforce_eager": "${env.ENFORCE_EAGER:=False}",
+            "gpu_memory_utilization": "${env.GPU_MEMORY_UTILIZATION:=0.3}",
         }
diff --git a/llama_stack/providers/inline/scoring/braintrust/config.py b/llama_stack/providers/inline/scoring/braintrust/config.py
index 4a80f1e4f..f44d27f96 100644
--- a/llama_stack/providers/inline/scoring/braintrust/config.py
+++ b/llama_stack/providers/inline/scoring/braintrust/config.py
@@ -17,5 +17,5 @@ class BraintrustScoringConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "openai_api_key": "${env.OPENAI_API_KEY:}",
+            "openai_api_key": "${env.OPENAI_API_KEY:+}",
         }
diff --git a/llama_stack/providers/inline/telemetry/meta_reference/config.py b/llama_stack/providers/inline/telemetry/meta_reference/config.py
index 2baa204c9..50dd8a788 100644
--- a/llama_stack/providers/inline/telemetry/meta_reference/config.py
+++ b/llama_stack/providers/inline/telemetry/meta_reference/config.py
@@ -20,12 +20,12 @@ class TelemetrySink(StrEnum):
 
 
 class TelemetryConfig(BaseModel):
-    otel_trace_endpoint: str = Field(
-        default="http://localhost:4318/v1/traces",
+    otel_trace_endpoint: str | None = Field(
+        default=None,
         description="The OpenTelemetry collector endpoint URL for traces",
     )
-    otel_metric_endpoint: str = Field(
-        default="http://localhost:4318/v1/metrics",
+    otel_metric_endpoint: str | None = Field(
+        default=None,
         description="The OpenTelemetry collector endpoint URL for metrics",
     )
     service_name: str = Field(
@@ -52,7 +52,7 @@ class TelemetryConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str, db_name: str = "trace_store.db") -> dict[str, Any]:
         return {
-            "service_name": "${env.OTEL_SERVICE_NAME:\u200b}",
-            "sinks": "${env.TELEMETRY_SINKS:console,sqlite}",
-            "sqlite_db_path": "${env.SQLITE_STORE_DIR:" + __distro_dir__ + "}/" + db_name,
+            "service_name": "${env.OTEL_SERVICE_NAME:=\u200b}",
+            "sinks": "${env.TELEMETRY_SINKS:=console,sqlite}",
+            "sqlite_db_path": "${env.SQLITE_STORE_DIR:=" + __distro_dir__ + "}/" + db_name,
         }
diff --git a/llama_stack/providers/inline/telemetry/meta_reference/telemetry.py b/llama_stack/providers/inline/telemetry/meta_reference/telemetry.py
index 0f6cf8619..98f5bf5a1 100644
--- a/llama_stack/providers/inline/telemetry/meta_reference/telemetry.py
+++ b/llama_stack/providers/inline/telemetry/meta_reference/telemetry.py
@@ -87,12 +87,16 @@ class TelemetryAdapter(TelemetryDatasetMixin, Telemetry):
             trace.set_tracer_provider(provider)
             _TRACER_PROVIDER = provider
             if TelemetrySink.OTEL_TRACE in self.config.sinks:
+                if self.config.otel_trace_endpoint is None:
+                    raise ValueError("otel_trace_endpoint is required when OTEL_TRACE is enabled")
                 span_exporter = OTLPSpanExporter(
                     endpoint=self.config.otel_trace_endpoint,
                 )
                 span_processor = BatchSpanProcessor(span_exporter)
                 trace.get_tracer_provider().add_span_processor(span_processor)
             if TelemetrySink.OTEL_METRIC in self.config.sinks:
+                if self.config.otel_metric_endpoint is None:
+                    raise ValueError("otel_metric_endpoint is required when OTEL_METRIC is enabled")
                 metric_reader = PeriodicExportingMetricReader(
                     OTLPMetricExporter(
                         endpoint=self.config.otel_metric_endpoint,
diff --git a/llama_stack/providers/inline/vector_io/qdrant/config.py b/llama_stack/providers/inline/vector_io/qdrant/config.py
index 283724b41..7cc91d918 100644
--- a/llama_stack/providers/inline/vector_io/qdrant/config.py
+++ b/llama_stack/providers/inline/vector_io/qdrant/config.py
@@ -19,5 +19,5 @@ class QdrantVectorIOConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str) -> dict[str, Any]:
         return {
-            "path": "${env.QDRANT_PATH:~/.llama/" + __distro_dir__ + "}/" + "qdrant.db",
+            "path": "${env.QDRANT_PATH:=~/.llama/" + __distro_dir__ + "}/" + "qdrant.db",
         }
diff --git a/llama_stack/providers/inline/vector_io/sqlite_vec/config.py b/llama_stack/providers/inline/vector_io/sqlite_vec/config.py
index cb806cb39..4c57f4aba 100644
--- a/llama_stack/providers/inline/vector_io/sqlite_vec/config.py
+++ b/llama_stack/providers/inline/vector_io/sqlite_vec/config.py
@@ -15,5 +15,5 @@ class SQLiteVectorIOConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str) -> dict[str, Any]:
         return {
-            "db_path": "${env.SQLITE_STORE_DIR:" + __distro_dir__ + "}/" + "sqlite_vec.db",
+            "db_path": "${env.SQLITE_STORE_DIR:=" + __distro_dir__ + "}/" + "sqlite_vec.db",
         }
diff --git a/llama_stack/providers/remote/datasetio/nvidia/config.py b/llama_stack/providers/remote/datasetio/nvidia/config.py
index e616ce25c..0f5ea22e9 100644
--- a/llama_stack/providers/remote/datasetio/nvidia/config.py
+++ b/llama_stack/providers/remote/datasetio/nvidia/config.py
@@ -54,8 +54,8 @@ class NvidiaDatasetIOConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "api_key": "${env.NVIDIA_API_KEY:}",
-            "dataset_namespace": "${env.NVIDIA_DATASET_NAMESPACE:default}",
-            "project_id": "${env.NVIDIA_PROJECT_ID:test-project}",
-            "datasets_url": "${env.NVIDIA_DATASETS_URL:http://nemo.test}",
+            "api_key": "${env.NVIDIA_API_KEY:+}",
+            "dataset_namespace": "${env.NVIDIA_DATASET_NAMESPACE:=default}",
+            "project_id": "${env.NVIDIA_PROJECT_ID:=test-project}",
+            "datasets_url": "${env.NVIDIA_DATASETS_URL:=http://nemo.test}",
         }
diff --git a/llama_stack/providers/remote/eval/nvidia/config.py b/llama_stack/providers/remote/eval/nvidia/config.py
index 5c8f9ff76..7a1c04304 100644
--- a/llama_stack/providers/remote/eval/nvidia/config.py
+++ b/llama_stack/providers/remote/eval/nvidia/config.py
@@ -25,5 +25,5 @@ class NVIDIAEvalConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "evaluator_url": "${env.NVIDIA_EVALUATOR_URL:http://localhost:7331}",
+            "evaluator_url": "${env.NVIDIA_EVALUATOR_URL:=http://localhost:7331}",
         }
diff --git a/llama_stack/providers/remote/inference/nvidia/config.py b/llama_stack/providers/remote/inference/nvidia/config.py
index 4c449edc2..6369928bb 100644
--- a/llama_stack/providers/remote/inference/nvidia/config.py
+++ b/llama_stack/providers/remote/inference/nvidia/config.py
@@ -55,7 +55,7 @@ class NVIDIAConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "url": "${env.NVIDIA_BASE_URL:https://integrate.api.nvidia.com}",
-            "api_key": "${env.NVIDIA_API_KEY:}",
-            "append_api_version": "${env.NVIDIA_APPEND_API_VERSION:True}",
+            "url": "${env.NVIDIA_BASE_URL:=https://integrate.api.nvidia.com}",
+            "api_key": "${env.NVIDIA_API_KEY:+}",
+            "append_api_version": "${env.NVIDIA_APPEND_API_VERSION:=True}",
         }
diff --git a/llama_stack/providers/remote/inference/ollama/config.py b/llama_stack/providers/remote/inference/ollama/config.py
index 37b827f4f..b2cc4d8a7 100644
--- a/llama_stack/providers/remote/inference/ollama/config.py
+++ b/llama_stack/providers/remote/inference/ollama/config.py
@@ -17,7 +17,7 @@ class OllamaImplConfig(BaseModel):
 
     @classmethod
     def sample_run_config(
-        cls, url: str = "${env.OLLAMA_URL:http://localhost:11434}", raise_on_connect_error: bool = True, **kwargs
+        cls, url: str = "${env.OLLAMA_URL:=http://localhost:11434}", raise_on_connect_error: bool = True, **kwargs
     ) -> dict[str, Any]:
         return {
             "url": url,
diff --git a/llama_stack/providers/remote/inference/runpod/config.py b/llama_stack/providers/remote/inference/runpod/config.py
index e3913dc35..ff32a971c 100644
--- a/llama_stack/providers/remote/inference/runpod/config.py
+++ b/llama_stack/providers/remote/inference/runpod/config.py
@@ -25,6 +25,6 @@ class RunpodImplConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs: Any) -> dict[str, Any]:
         return {
-            "url": "${env.RUNPOD_URL:}",
-            "api_token": "${env.RUNPOD_API_TOKEN:}",
+            "url": "${env.RUNPOD_URL:+}",
+            "api_token": "${env.RUNPOD_API_TOKEN:+}",
         }
diff --git a/llama_stack/providers/remote/inference/together/config.py b/llama_stack/providers/remote/inference/together/config.py
index 5c7f60519..121e2cae7 100644
--- a/llama_stack/providers/remote/inference/together/config.py
+++ b/llama_stack/providers/remote/inference/together/config.py
@@ -26,5 +26,5 @@ class TogetherImplConfig(BaseModel):
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
             "url": "https://api.together.xyz/v1",
-            "api_key": "${env.TOGETHER_API_KEY:}",
+            "api_key": "${env.TOGETHER_API_KEY:+}",
         }
diff --git a/llama_stack/providers/remote/inference/vllm/config.py b/llama_stack/providers/remote/inference/vllm/config.py
index 99abddf51..e11efa7f0 100644
--- a/llama_stack/providers/remote/inference/vllm/config.py
+++ b/llama_stack/providers/remote/inference/vllm/config.py
@@ -34,9 +34,6 @@ class VLLMInferenceAdapterConfig(BaseModel):
     @classmethod
     def validate_tls_verify(cls, v):
         if isinstance(v, str):
-            # Check if it's a boolean string
-            if v.lower() in ("true", "false"):
-                return v.lower() == "true"
             # Otherwise, treat it as a cert path
             cert_path = Path(v).expanduser().resolve()
             if not cert_path.exists():
@@ -54,7 +51,7 @@ class VLLMInferenceAdapterConfig(BaseModel):
     ):
         return {
             "url": url,
-            "max_tokens": "${env.VLLM_MAX_TOKENS:4096}",
-            "api_token": "${env.VLLM_API_TOKEN:fake}",
-            "tls_verify": "${env.VLLM_TLS_VERIFY:true}",
+            "max_tokens": "${env.VLLM_MAX_TOKENS:=4096}",
+            "api_token": "${env.VLLM_API_TOKEN:=fake}",
+            "tls_verify": "${env.VLLM_TLS_VERIFY:=true}",
         }
diff --git a/llama_stack/providers/remote/inference/watsonx/config.py b/llama_stack/providers/remote/inference/watsonx/config.py
index 5eda9c5c0..9534eceeb 100644
--- a/llama_stack/providers/remote/inference/watsonx/config.py
+++ b/llama_stack/providers/remote/inference/watsonx/config.py
@@ -40,7 +40,7 @@ class WatsonXConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "url": "${env.WATSONX_BASE_URL:https://us-south.ml.cloud.ibm.com}",
-            "api_key": "${env.WATSONX_API_KEY:}",
-            "project_id": "${env.WATSONX_PROJECT_ID:}",
+            "url": "${env.WATSONX_BASE_URL:=https://us-south.ml.cloud.ibm.com}",
+            "api_key": "${env.WATSONX_API_KEY:+}",
+            "project_id": "${env.WATSONX_PROJECT_ID:+}",
         }
diff --git a/llama_stack/providers/remote/post_training/nvidia/config.py b/llama_stack/providers/remote/post_training/nvidia/config.py
index fa08b6e3f..ea6dff0b5 100644
--- a/llama_stack/providers/remote/post_training/nvidia/config.py
+++ b/llama_stack/providers/remote/post_training/nvidia/config.py
@@ -55,10 +55,10 @@ class NvidiaPostTrainingConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "api_key": "${env.NVIDIA_API_KEY:}",
-            "dataset_namespace": "${env.NVIDIA_DATASET_NAMESPACE:default}",
-            "project_id": "${env.NVIDIA_PROJECT_ID:test-project}",
-            "customizer_url": "${env.NVIDIA_CUSTOMIZER_URL:http://nemo.test}",
+            "api_key": "${env.NVIDIA_API_KEY:+}",
+            "dataset_namespace": "${env.NVIDIA_DATASET_NAMESPACE:=default}",
+            "project_id": "${env.NVIDIA_PROJECT_ID:=test-project}",
+            "customizer_url": "${env.NVIDIA_CUSTOMIZER_URL:=http://nemo.test}",
         }
 
 
diff --git a/llama_stack/providers/remote/safety/nvidia/config.py b/llama_stack/providers/remote/safety/nvidia/config.py
index ddf5a3a0b..1c618f4f4 100644
--- a/llama_stack/providers/remote/safety/nvidia/config.py
+++ b/llama_stack/providers/remote/safety/nvidia/config.py
@@ -35,6 +35,6 @@ class NVIDIASafetyConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, **kwargs) -> dict[str, Any]:
         return {
-            "guardrails_service_url": "${env.GUARDRAILS_SERVICE_URL:http://localhost:7331}",
-            "config_id": "${env.NVIDIA_GUARDRAILS_CONFIG_ID:self-check}",
+            "guardrails_service_url": "${env.GUARDRAILS_SERVICE_URL:=http://localhost:7331}",
+            "config_id": "${env.NVIDIA_GUARDRAILS_CONFIG_ID:=self-check}",
         }
diff --git a/llama_stack/providers/remote/tool_runtime/brave_search/config.py b/llama_stack/providers/remote/tool_runtime/brave_search/config.py
index 37ba21304..93b97a1b2 100644
--- a/llama_stack/providers/remote/tool_runtime/brave_search/config.py
+++ b/llama_stack/providers/remote/tool_runtime/brave_search/config.py
@@ -22,6 +22,6 @@ class BraveSearchToolConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str) -> dict[str, Any]:
         return {
-            "api_key": "${env.BRAVE_SEARCH_API_KEY:}",
+            "api_key": "${env.BRAVE_SEARCH_API_KEY:+}",
             "max_results": 3,
         }
diff --git a/llama_stack/providers/remote/tool_runtime/tavily_search/config.py b/llama_stack/providers/remote/tool_runtime/tavily_search/config.py
index c9b18d30d..5bdd27807 100644
--- a/llama_stack/providers/remote/tool_runtime/tavily_search/config.py
+++ b/llama_stack/providers/remote/tool_runtime/tavily_search/config.py
@@ -22,6 +22,6 @@ class TavilySearchToolConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str) -> dict[str, Any]:
         return {
-            "api_key": "${env.TAVILY_SEARCH_API_KEY:}",
+            "api_key": "${env.TAVILY_SEARCH_API_KEY:+}",
             "max_results": 3,
         }
diff --git a/llama_stack/providers/remote/tool_runtime/wolfram_alpha/config.py b/llama_stack/providers/remote/tool_runtime/wolfram_alpha/config.py
index aefc86bd6..b5b10e371 100644
--- a/llama_stack/providers/remote/tool_runtime/wolfram_alpha/config.py
+++ b/llama_stack/providers/remote/tool_runtime/wolfram_alpha/config.py
@@ -17,5 +17,5 @@ class WolframAlphaToolConfig(BaseModel):
     @classmethod
     def sample_run_config(cls, __distro_dir__: str, **kwargs: Any) -> dict[str, Any]:
         return {
-            "api_key": "${env.WOLFRAM_ALPHA_API_KEY:}",
+            "api_key": "${env.WOLFRAM_ALPHA_API_KEY:+}",
         }
diff --git a/llama_stack/providers/remote/vector_io/pgvector/config.py b/llama_stack/providers/remote/vector_io/pgvector/config.py
index 04b92a2e4..041e864ca 100644
--- a/llama_stack/providers/remote/vector_io/pgvector/config.py
+++ b/llama_stack/providers/remote/vector_io/pgvector/config.py
@@ -22,8 +22,8 @@ class PGVectorVectorIOConfig(BaseModel):
     @classmethod
     def sample_run_config(
         cls,
-        host: str = "${env.PGVECTOR_HOST:localhost}",
-        port: int = "${env.PGVECTOR_PORT:5432}",
+        host: str = "${env.PGVECTOR_HOST:=localhost}",
+        port: int = "${env.PGVECTOR_PORT:=5432}",
         db: str = "${env.PGVECTOR_DB}",
         user: str = "${env.PGVECTOR_USER}",
         password: str = "${env.PGVECTOR_PASSWORD}",
diff --git a/llama_stack/providers/utils/kvstore/config.py b/llama_stack/providers/utils/kvstore/config.py
index e966e13ba..a45ff4ce8 100644
--- a/llama_stack/providers/utils/kvstore/config.py
+++ b/llama_stack/providers/utils/kvstore/config.py
@@ -45,8 +45,8 @@ class RedisKVStoreConfig(CommonConfig):
         return {
             "type": "redis",
             "namespace": None,
-            "host": "${env.REDIS_HOST:localhost}",
-            "port": "${env.REDIS_PORT:6379}",
+            "host": "${env.REDIS_HOST:=localhost}",
+            "port": "${env.REDIS_PORT:=6379}",
         }
 
 
@@ -66,7 +66,7 @@ class SqliteKVStoreConfig(CommonConfig):
         return {
             "type": "sqlite",
             "namespace": None,
-            "db_path": "${env.SQLITE_STORE_DIR:" + __distro_dir__ + "}/" + db_name,
+            "db_path": "${env.SQLITE_STORE_DIR:=" + __distro_dir__ + "}/" + db_name,
         }
 
 
@@ -84,12 +84,12 @@ class PostgresKVStoreConfig(CommonConfig):
         return {
             "type": "postgres",
             "namespace": None,
-            "host": "${env.POSTGRES_HOST:localhost}",
-            "port": "${env.POSTGRES_PORT:5432}",
-            "db": "${env.POSTGRES_DB:llamastack}",
-            "user": "${env.POSTGRES_USER:llamastack}",
-            "password": "${env.POSTGRES_PASSWORD:llamastack}",
-            "table_name": "${env.POSTGRES_TABLE_NAME:" + table_name + "}",
+            "host": "${env.POSTGRES_HOST:=localhost}",
+            "port": "${env.POSTGRES_PORT:=5432}",
+            "db": "${env.POSTGRES_DB:=llamastack}",
+            "user": "${env.POSTGRES_USER:=llamastack}",
+            "password": "${env.POSTGRES_PASSWORD:=llamastack}",
+            "table_name": "${env.POSTGRES_TABLE_NAME:=" + table_name + "}",
         }
 
     @classmethod
@@ -131,12 +131,12 @@ class MongoDBKVStoreConfig(CommonConfig):
         return {
             "type": "mongodb",
             "namespace": None,
-            "host": "${env.MONGODB_HOST:localhost}",
-            "port": "${env.MONGODB_PORT:5432}",
+            "host": "${env.MONGODB_HOST:=localhost}",
+            "port": "${env.MONGODB_PORT:=5432}",
             "db": "${env.MONGODB_DB}",
             "user": "${env.MONGODB_USER}",
             "password": "${env.MONGODB_PASSWORD}",
-            "collection_name": "${env.MONGODB_COLLECTION_NAME:" + collection_name + "}",
+            "collection_name": "${env.MONGODB_COLLECTION_NAME:=" + collection_name + "}",
         }
 
 
diff --git a/llama_stack/providers/utils/sqlstore/sqlstore.py b/llama_stack/providers/utils/sqlstore/sqlstore.py
index edc7672a3..d558a2a26 100644
--- a/llama_stack/providers/utils/sqlstore/sqlstore.py
+++ b/llama_stack/providers/utils/sqlstore/sqlstore.py
@@ -50,7 +50,7 @@ class SqliteSqlStoreConfig(SqlAlchemySqlStoreConfig):
     def sample_run_config(cls, __distro_dir__: str, db_name: str = "sqlstore.db"):
         return cls(
             type="sqlite",
-            db_path="${env.SQLITE_STORE_DIR:" + __distro_dir__ + "}/" + db_name,
+            db_path="${env.SQLITE_STORE_DIR:=" + __distro_dir__ + "}/" + db_name,
         )
 
     @property
@@ -78,11 +78,11 @@ class PostgresSqlStoreConfig(SqlAlchemySqlStoreConfig):
     def sample_run_config(cls, **kwargs):
         return cls(
             type="postgres",
-            host="${env.POSTGRES_HOST:localhost}",
-            port="${env.POSTGRES_PORT:5432}",
-            db="${env.POSTGRES_DB:llamastack}",
-            user="${env.POSTGRES_USER:llamastack}",
-            password="${env.POSTGRES_PASSWORD:llamastack}",
+            host="${env.POSTGRES_HOST:=localhost}",
+            port="${env.POSTGRES_PORT:=5432}",
+            db="${env.POSTGRES_DB:=llamastack}",
+            user="${env.POSTGRES_USER:=llamastack}",
+            password="${env.POSTGRES_PASSWORD:=llamastack}",
         )
 
 
diff --git a/llama_stack/templates/bedrock/build.yaml b/llama_stack/templates/bedrock/build.yaml
index 97a06f77a..1a2c883fa 100644
--- a/llama_stack/templates/bedrock/build.yaml
+++ b/llama_stack/templates/bedrock/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use AWS Bedrock for running LLM inference and safety
   providers:
diff --git a/llama_stack/templates/bedrock/run.yaml b/llama_stack/templates/bedrock/run.yaml
index 8033b2086..61bc83f02 100644
--- a/llama_stack/templates/bedrock/run.yaml
+++ b/llama_stack/templates/bedrock/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: bedrock
 apis:
 - agents
@@ -22,7 +22,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/faiss_store.db
   safety:
   - provider_id: bedrock
     provider_type: remote::bedrock
@@ -34,17 +34,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -52,7 +52,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -60,14 +60,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -78,17 +78,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -98,10 +98,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/bedrock}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/bedrock}/inference_store.db
 models:
 - metadata: {}
   model_id: meta.llama3-1-8b-instruct-v1:0
diff --git a/llama_stack/templates/cerebras/build.yaml b/llama_stack/templates/cerebras/build.yaml
index f26f4ed9b..ecd0ac418 100644
--- a/llama_stack/templates/cerebras/build.yaml
+++ b/llama_stack/templates/cerebras/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use Cerebras for running LLM inference
   providers:
diff --git a/llama_stack/templates/cerebras/run.yaml b/llama_stack/templates/cerebras/run.yaml
index 490648302..9bd8fcc7c 100644
--- a/llama_stack/templates/cerebras/run.yaml
+++ b/llama_stack/templates/cerebras/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: cerebras
 apis:
 - agents
@@ -32,7 +32,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/faiss_store.db
   agents:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -40,10 +40,10 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/responses_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -51,7 +51,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -59,14 +59,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -77,34 +77,34 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/trace_store.db
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/cerebras}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/cerebras}/inference_store.db
 models:
 - metadata: {}
   model_id: llama3.1-8b
diff --git a/llama_stack/templates/ci-tests/build.yaml b/llama_stack/templates/ci-tests/build.yaml
index 9f4fbbdda..c061d0793 100644
--- a/llama_stack/templates/ci-tests/build.yaml
+++ b/llama_stack/templates/ci-tests/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Distribution for running e2e tests in CI
   providers:
diff --git a/llama_stack/templates/ci-tests/run.yaml b/llama_stack/templates/ci-tests/run.yaml
index 92497b0bf..4b7de1c0c 100644
--- a/llama_stack/templates/ci-tests/run.yaml
+++ b/llama_stack/templates/ci-tests/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: ci-tests
 apis:
 - agents
@@ -24,7 +24,7 @@ providers:
   - provider_id: sqlite-vec
     provider_type: inline::sqlite-vec
     config:
-      db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/sqlite_vec.db
+      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/sqlite_vec.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -37,17 +37,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -55,7 +55,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -63,14 +63,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -81,17 +81,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -101,10 +101,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ci-tests}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ci-tests}/inference_store.db
 models:
 - metadata: {}
   model_id: accounts/fireworks/models/llama-v3p1-8b-instruct
diff --git a/llama_stack/templates/dell/build.yaml b/llama_stack/templates/dell/build.yaml
index 513df16c1..ff8d58a08 100644
--- a/llama_stack/templates/dell/build.yaml
+++ b/llama_stack/templates/dell/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Dell's distribution of Llama Stack. TGI inference via Dell's custom
     container
diff --git a/llama_stack/templates/dell/run-with-safety.yaml b/llama_stack/templates/dell/run-with-safety.yaml
index 22cf1fd24..7f1d0a8c0 100644
--- a/llama_stack/templates/dell/run-with-safety.yaml
+++ b/llama_stack/templates/dell/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: dell
 apis:
 - agents
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,27 +84,27 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/dell/run.yaml b/llama_stack/templates/dell/run.yaml
index aeca2fc26..310f3cc20 100644
--- a/llama_stack/templates/dell/run.yaml
+++ b/llama_stack/templates/dell/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: dell
 apis:
 - agents
@@ -36,17 +36,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -54,7 +54,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -62,14 +62,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -80,27 +80,27 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/dell}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/dell}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/fireworks/build.yaml b/llama_stack/templates/fireworks/build.yaml
index 53b47da41..eb08c1d43 100644
--- a/llama_stack/templates/fireworks/build.yaml
+++ b/llama_stack/templates/fireworks/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use Fireworks.AI for running LLM inference
   providers:
diff --git a/llama_stack/templates/fireworks/run-with-safety.yaml b/llama_stack/templates/fireworks/run-with-safety.yaml
index 302328486..6265f5cae 100644
--- a/llama_stack/templates/fireworks/run-with-safety.yaml
+++ b/llama_stack/templates/fireworks/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: fireworks
 apis:
 - agents
@@ -28,7 +28,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -46,17 +46,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -64,7 +64,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -72,14 +72,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -90,30 +90,30 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   files:
   - provider_id: meta-reference-files
     provider_type: inline::localfs
     config:
-      storage_dir: ${env.FILES_STORAGE_DIR:~/.llama/distributions/fireworks/files}
+      storage_dir: ${env.FILES_STORAGE_DIR:=~/.llama/distributions/fireworks/files}
       metadata_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/files_metadata.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/files_metadata.db
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
@@ -122,10 +122,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/inference_store.db
 models:
 - metadata: {}
   model_id: accounts/fireworks/models/llama-v3p1-8b-instruct
diff --git a/llama_stack/templates/fireworks/run.yaml b/llama_stack/templates/fireworks/run.yaml
index a31ed732b..e10404e92 100644
--- a/llama_stack/templates/fireworks/run.yaml
+++ b/llama_stack/templates/fireworks/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: fireworks
 apis:
 - agents
@@ -28,7 +28,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -41,17 +41,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -59,7 +59,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -67,14 +67,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -85,30 +85,30 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   files:
   - provider_id: meta-reference-files
     provider_type: inline::localfs
     config:
-      storage_dir: ${env.FILES_STORAGE_DIR:~/.llama/distributions/fireworks/files}
+      storage_dir: ${env.FILES_STORAGE_DIR:=~/.llama/distributions/fireworks/files}
       metadata_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/files_metadata.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/files_metadata.db
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
@@ -117,10 +117,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/fireworks}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/fireworks}/inference_store.db
 models:
 - metadata: {}
   model_id: accounts/fireworks/models/llama-v3p1-8b-instruct
diff --git a/llama_stack/templates/groq/build.yaml b/llama_stack/templates/groq/build.yaml
index 819df22f0..7e50a899f 100644
--- a/llama_stack/templates/groq/build.yaml
+++ b/llama_stack/templates/groq/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use Groq for running LLM inference
   providers:
diff --git a/llama_stack/templates/groq/run.yaml b/llama_stack/templates/groq/run.yaml
index 7f1912a6f..21c8f7e0f 100644
--- a/llama_stack/templates/groq/run.yaml
+++ b/llama_stack/templates/groq/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: groq
 apis:
 - agents
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,27 +84,27 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/groq}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/groq}/inference_store.db
 models:
 - metadata: {}
   model_id: groq/llama3-8b-8192
diff --git a/llama_stack/templates/hf-endpoint/build.yaml b/llama_stack/templates/hf-endpoint/build.yaml
index 8ede83694..9fca9ac22 100644
--- a/llama_stack/templates/hf-endpoint/build.yaml
+++ b/llama_stack/templates/hf-endpoint/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use (an external) Hugging Face Inference Endpoint for running LLM inference
   providers:
diff --git a/llama_stack/templates/hf-endpoint/run-with-safety.yaml b/llama_stack/templates/hf-endpoint/run-with-safety.yaml
index 8b00f4ba5..2ae1d7685 100644
--- a/llama_stack/templates/hf-endpoint/run-with-safety.yaml
+++ b/llama_stack/templates/hf-endpoint/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: hf-endpoint
 apis:
 - agents
@@ -32,7 +32,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -45,17 +45,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -63,7 +63,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -71,14 +71,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -89,17 +89,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -109,10 +109,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/hf-endpoint/run.yaml b/llama_stack/templates/hf-endpoint/run.yaml
index 8a9cd5c49..3ec5ae9c1 100644
--- a/llama_stack/templates/hf-endpoint/run.yaml
+++ b/llama_stack/templates/hf-endpoint/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: hf-endpoint
 apis:
 - agents
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,17 +84,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -104,10 +104,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-endpoint}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-endpoint}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/hf-serverless/build.yaml b/llama_stack/templates/hf-serverless/build.yaml
index d0752db9a..214245116 100644
--- a/llama_stack/templates/hf-serverless/build.yaml
+++ b/llama_stack/templates/hf-serverless/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use (an external) Hugging Face Inference Endpoint for running LLM inference
   providers:
diff --git a/llama_stack/templates/hf-serverless/run-with-safety.yaml b/llama_stack/templates/hf-serverless/run-with-safety.yaml
index fec64c1df..3871b77e7 100644
--- a/llama_stack/templates/hf-serverless/run-with-safety.yaml
+++ b/llama_stack/templates/hf-serverless/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: hf-serverless
 apis:
 - agents
@@ -32,7 +32,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -45,17 +45,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -63,7 +63,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -71,14 +71,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -89,17 +89,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -109,10 +109,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/hf-serverless/run.yaml b/llama_stack/templates/hf-serverless/run.yaml
index d4a6286d7..0a5b59400 100644
--- a/llama_stack/templates/hf-serverless/run.yaml
+++ b/llama_stack/templates/hf-serverless/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: hf-serverless
 apis:
 - agents
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,17 +84,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -104,10 +104,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/hf-serverless}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/hf-serverless}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/llama_api/build.yaml b/llama_stack/templates/llama_api/build.yaml
index 857e5f014..44a42594a 100644
--- a/llama_stack/templates/llama_api/build.yaml
+++ b/llama_stack/templates/llama_api/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Distribution for running e2e tests in CI
   providers:
diff --git a/llama_stack/templates/llama_api/llama_api.py b/llama_stack/templates/llama_api/llama_api.py
index 723cc44a3..7631781af 100644
--- a/llama_stack/templates/llama_api/llama_api.py
+++ b/llama_stack/templates/llama_api/llama_api.py
@@ -41,7 +41,7 @@ def get_inference_providers() -> tuple[list[Provider], list[ModelInput]]:
         (
             "llama-openai-compat",
             LLLAMA_MODEL_ENTRIES,
-            LlamaCompatConfig.sample_run_config(api_key="${env.LLAMA_API_KEY:}"),
+            LlamaCompatConfig.sample_run_config(api_key="${env.LLAMA_API_KEY:+}"),
         ),
     ]
     inference_providers = []
@@ -85,17 +85,17 @@ def get_distribution_template() -> DistributionTemplate:
             config=SQLiteVectorIOConfig.sample_run_config(f"~/.llama/distributions/{name}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_CHROMADB+chromadb}",
+            provider_id="${env.ENABLE_CHROMADB:+chromadb}",
             provider_type="remote::chromadb",
-            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:}"),
+            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:+}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_PGVECTOR+pgvector}",
+            provider_id="${env.ENABLE_PGVECTOR:+pgvector}",
             provider_type="remote::pgvector",
             config=PGVectorVectorIOConfig.sample_run_config(
-                db="${env.PGVECTOR_DB:}",
-                user="${env.PGVECTOR_USER:}",
-                password="${env.PGVECTOR_PASSWORD:}",
+                db="${env.PGVECTOR_DB:+}",
+                user="${env.PGVECTOR_USER:+}",
+                password="${env.PGVECTOR_PASSWORD:+}",
             ),
         ),
     ]
diff --git a/llama_stack/templates/llama_api/run.yaml b/llama_stack/templates/llama_api/run.yaml
index 2185eb4fc..b627ed2f1 100644
--- a/llama_stack/templates/llama_api/run.yaml
+++ b/llama_stack/templates/llama_api/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: llama_api
 apis:
 - agents
@@ -16,7 +16,7 @@ providers:
     provider_type: remote::llama-openai-compat
     config:
       openai_compat_api_base: https://api.llama.com/compat/v1/
-      api_key: ${env.LLAMA_API_KEY:}
+      api_key: ${env.LLAMA_API_KEY:+}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -24,19 +24,19 @@ providers:
   - provider_id: sqlite-vec
     provider_type: inline::sqlite-vec
     config:
-      db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/sqlite_vec.db
-  - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/sqlite_vec.db
+  - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
     provider_type: remote::chromadb
     config:
-      url: ${env.CHROMADB_URL:}
-  - provider_id: ${env.ENABLE_PGVECTOR+pgvector}
+      url: ${env.CHROMADB_URL:+}
+  - provider_id: ${env.ENABLE_PGVECTOR:+pgvector}
     provider_type: remote::pgvector
     config:
-      host: ${env.PGVECTOR_HOST:localhost}
-      port: ${env.PGVECTOR_PORT:5432}
-      db: ${env.PGVECTOR_DB:}
-      user: ${env.PGVECTOR_USER:}
-      password: ${env.PGVECTOR_PASSWORD:}
+      host: ${env.PGVECTOR_HOST:=localhost}
+      port: ${env.PGVECTOR_PORT:=5432}
+      db: ${env.PGVECTOR_DB:+}
+      user: ${env.PGVECTOR_USER:+}
+      password: ${env.PGVECTOR_PASSWORD:+}
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -49,17 +49,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -67,7 +67,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -75,14 +75,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -93,17 +93,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -113,10 +113,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/llama_api}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/llama_api}/inference_store.db
 models:
 - metadata: {}
   model_id: Llama-3.3-70B-Instruct
diff --git a/llama_stack/templates/meta-reference-gpu/build.yaml b/llama_stack/templates/meta-reference-gpu/build.yaml
index 53ad411e3..2119eeddd 100644
--- a/llama_stack/templates/meta-reference-gpu/build.yaml
+++ b/llama_stack/templates/meta-reference-gpu/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use Meta Reference for running LLM inference
   providers:
diff --git a/llama_stack/templates/meta-reference-gpu/run-with-safety.yaml b/llama_stack/templates/meta-reference-gpu/run-with-safety.yaml
index e65445a9e..6b15a1e01 100644
--- a/llama_stack/templates/meta-reference-gpu/run-with-safety.yaml
+++ b/llama_stack/templates/meta-reference-gpu/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: meta-reference-gpu
 apis:
 - agents
@@ -18,10 +18,10 @@ providers:
       model: ${env.INFERENCE_MODEL}
       checkpoint_dir: ${env.INFERENCE_CHECKPOINT_DIR:null}
       quantization:
-        type: ${env.QUANTIZATION_TYPE:bf16}
-      model_parallel_size: ${env.MODEL_PARALLEL_SIZE:0}
-      max_batch_size: ${env.MAX_BATCH_SIZE:1}
-      max_seq_len: ${env.MAX_SEQ_LEN:4096}
+        type: ${env.QUANTIZATION_TYPE:=bf16}
+      model_parallel_size: ${env.MODEL_PARALLEL_SIZE:=0}
+      max_batch_size: ${env.MAX_BATCH_SIZE:=1}
+      max_seq_len: ${env.MAX_SEQ_LEN:=4096}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -31,10 +31,10 @@ providers:
       model: ${env.SAFETY_MODEL}
       checkpoint_dir: ${env.SAFETY_CHECKPOINT_DIR:null}
       quantization:
-        type: ${env.QUANTIZATION_TYPE:bf16}
-      model_parallel_size: ${env.MODEL_PARALLEL_SIZE:0}
-      max_batch_size: ${env.MAX_BATCH_SIZE:1}
-      max_seq_len: ${env.MAX_SEQ_LEN:4096}
+        type: ${env.QUANTIZATION_TYPE:=bf16}
+      model_parallel_size: ${env.MODEL_PARALLEL_SIZE:=0}
+      max_batch_size: ${env.MAX_BATCH_SIZE:=1}
+      max_seq_len: ${env.MAX_SEQ_LEN:=4096}
   vector_io:
   - provider_id: faiss
     provider_type: inline::faiss
@@ -42,7 +42,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -55,17 +55,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -73,7 +73,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -81,14 +81,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -99,17 +99,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -119,10 +119,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/meta-reference-gpu/run.yaml b/llama_stack/templates/meta-reference-gpu/run.yaml
index 8ef02f14d..1b44a0b3e 100644
--- a/llama_stack/templates/meta-reference-gpu/run.yaml
+++ b/llama_stack/templates/meta-reference-gpu/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: meta-reference-gpu
 apis:
 - agents
@@ -18,10 +18,10 @@ providers:
       model: ${env.INFERENCE_MODEL}
       checkpoint_dir: ${env.INFERENCE_CHECKPOINT_DIR:null}
       quantization:
-        type: ${env.QUANTIZATION_TYPE:bf16}
-      model_parallel_size: ${env.MODEL_PARALLEL_SIZE:0}
-      max_batch_size: ${env.MAX_BATCH_SIZE:1}
-      max_seq_len: ${env.MAX_SEQ_LEN:4096}
+        type: ${env.QUANTIZATION_TYPE:=bf16}
+      model_parallel_size: ${env.MODEL_PARALLEL_SIZE:=0}
+      max_batch_size: ${env.MAX_BATCH_SIZE:=1}
+      max_seq_len: ${env.MAX_SEQ_LEN:=4096}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -32,7 +32,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -45,17 +45,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -63,7 +63,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -71,14 +71,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -89,17 +89,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -109,10 +109,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/meta-reference-gpu}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/meta-reference-gpu}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/nvidia/build.yaml b/llama_stack/templates/nvidia/build.yaml
index 6bd8a0100..51685b2e3 100644
--- a/llama_stack/templates/nvidia/build.yaml
+++ b/llama_stack/templates/nvidia/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use NVIDIA NIM for running LLM inference, evaluation and safety
   providers:
diff --git a/llama_stack/templates/nvidia/run-with-safety.yaml b/llama_stack/templates/nvidia/run-with-safety.yaml
index eebfa1066..875fccc9d 100644
--- a/llama_stack/templates/nvidia/run-with-safety.yaml
+++ b/llama_stack/templates/nvidia/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: nvidia
 apis:
 - agents
@@ -16,14 +16,14 @@ providers:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      url: ${env.NVIDIA_BASE_URL:https://integrate.api.nvidia.com}
-      api_key: ${env.NVIDIA_API_KEY:}
-      append_api_version: ${env.NVIDIA_APPEND_API_VERSION:True}
+      url: ${env.NVIDIA_BASE_URL:=https://integrate.api.nvidia.com}
+      api_key: ${env.NVIDIA_API_KEY:+}
+      append_api_version: ${env.NVIDIA_APPEND_API_VERSION:=True}
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      guardrails_service_url: ${env.GUARDRAILS_SERVICE_URL:http://localhost:7331}
-      config_id: ${env.NVIDIA_GUARDRAILS_CONFIG_ID:self-check}
+      guardrails_service_url: ${env.GUARDRAILS_SERVICE_URL:=http://localhost:7331}
+      config_id: ${env.NVIDIA_GUARDRAILS_CONFIG_ID:=self-check}
   vector_io:
   - provider_id: faiss
     provider_type: inline::faiss
@@ -31,13 +31,13 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/faiss_store.db
   safety:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      guardrails_service_url: ${env.GUARDRAILS_SERVICE_URL:http://localhost:7331}
-      config_id: ${env.NVIDIA_GUARDRAILS_CONFIG_ID:self-check}
+      guardrails_service_url: ${env.GUARDRAILS_SERVICE_URL:=http://localhost:7331}
+      config_id: ${env.NVIDIA_GUARDRAILS_CONFIG_ID:=self-check}
   agents:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -45,30 +45,30 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/trace_store.db
   eval:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      evaluator_url: ${env.NVIDIA_EVALUATOR_URL:http://localhost:7331}
+      evaluator_url: ${env.NVIDIA_EVALUATOR_URL:=http://localhost:7331}
   post_training:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      api_key: ${env.NVIDIA_API_KEY:}
-      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:default}
-      project_id: ${env.NVIDIA_PROJECT_ID:test-project}
-      customizer_url: ${env.NVIDIA_CUSTOMIZER_URL:http://nemo.test}
+      api_key: ${env.NVIDIA_API_KEY:+}
+      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:=default}
+      project_id: ${env.NVIDIA_PROJECT_ID:=test-project}
+      customizer_url: ${env.NVIDIA_CUSTOMIZER_URL:=http://nemo.test}
   datasetio:
   - provider_id: localfs
     provider_type: inline::localfs
@@ -76,14 +76,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/localfs_datasetio.db
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      api_key: ${env.NVIDIA_API_KEY:}
-      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:default}
-      project_id: ${env.NVIDIA_PROJECT_ID:test-project}
-      datasets_url: ${env.NVIDIA_DATASETS_URL:http://nemo.test}
+      api_key: ${env.NVIDIA_API_KEY:+}
+      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:=default}
+      project_id: ${env.NVIDIA_PROJECT_ID:=test-project}
+      datasets_url: ${env.NVIDIA_DATASETS_URL:=http://nemo.test}
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -94,10 +94,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/nvidia/run.yaml b/llama_stack/templates/nvidia/run.yaml
index be0e3f6d1..4477d5244 100644
--- a/llama_stack/templates/nvidia/run.yaml
+++ b/llama_stack/templates/nvidia/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: nvidia
 apis:
 - agents
@@ -16,9 +16,9 @@ providers:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      url: ${env.NVIDIA_BASE_URL:https://integrate.api.nvidia.com}
-      api_key: ${env.NVIDIA_API_KEY:}
-      append_api_version: ${env.NVIDIA_APPEND_API_VERSION:True}
+      url: ${env.NVIDIA_BASE_URL:=https://integrate.api.nvidia.com}
+      api_key: ${env.NVIDIA_API_KEY:+}
+      append_api_version: ${env.NVIDIA_APPEND_API_VERSION:=True}
   vector_io:
   - provider_id: faiss
     provider_type: inline::faiss
@@ -26,13 +26,13 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/faiss_store.db
   safety:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      guardrails_service_url: ${env.GUARDRAILS_SERVICE_URL:http://localhost:7331}
-      config_id: ${env.NVIDIA_GUARDRAILS_CONFIG_ID:self-check}
+      guardrails_service_url: ${env.GUARDRAILS_SERVICE_URL:=http://localhost:7331}
+      config_id: ${env.NVIDIA_GUARDRAILS_CONFIG_ID:=self-check}
   agents:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -40,38 +40,38 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/trace_store.db
   eval:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      evaluator_url: ${env.NVIDIA_EVALUATOR_URL:http://localhost:7331}
+      evaluator_url: ${env.NVIDIA_EVALUATOR_URL:=http://localhost:7331}
   post_training:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      api_key: ${env.NVIDIA_API_KEY:}
-      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:default}
-      project_id: ${env.NVIDIA_PROJECT_ID:test-project}
-      customizer_url: ${env.NVIDIA_CUSTOMIZER_URL:http://nemo.test}
+      api_key: ${env.NVIDIA_API_KEY:+}
+      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:=default}
+      project_id: ${env.NVIDIA_PROJECT_ID:=test-project}
+      customizer_url: ${env.NVIDIA_CUSTOMIZER_URL:=http://nemo.test}
   datasetio:
   - provider_id: nvidia
     provider_type: remote::nvidia
     config:
-      api_key: ${env.NVIDIA_API_KEY:}
-      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:default}
-      project_id: ${env.NVIDIA_PROJECT_ID:test-project}
-      datasets_url: ${env.NVIDIA_DATASETS_URL:http://nemo.test}
+      api_key: ${env.NVIDIA_API_KEY:+}
+      dataset_namespace: ${env.NVIDIA_DATASET_NAMESPACE:=default}
+      project_id: ${env.NVIDIA_PROJECT_ID:=test-project}
+      datasets_url: ${env.NVIDIA_DATASETS_URL:=http://nemo.test}
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -82,10 +82,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/nvidia}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/nvidia}/inference_store.db
 models:
 - metadata: {}
   model_id: meta/llama3-8b-instruct
diff --git a/llama_stack/templates/ollama/build.yaml b/llama_stack/templates/ollama/build.yaml
index ebe0849f3..cbf4281a2 100644
--- a/llama_stack/templates/ollama/build.yaml
+++ b/llama_stack/templates/ollama/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use (an external) Ollama server for running LLM inference
   providers:
diff --git a/llama_stack/templates/ollama/run-with-safety.yaml b/llama_stack/templates/ollama/run-with-safety.yaml
index 2e1b7fdcc..5e906a12c 100644
--- a/llama_stack/templates/ollama/run-with-safety.yaml
+++ b/llama_stack/templates/ollama/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: ollama
 apis:
 - agents
@@ -17,7 +17,7 @@ providers:
   - provider_id: ollama
     provider_type: remote::ollama
     config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
+      url: ${env.OLLAMA_URL:=http://localhost:11434}
       raise_on_connect_error: true
   vector_io:
   - provider_id: faiss
@@ -26,7 +26,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -41,17 +41,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -59,7 +59,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -67,14 +67,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -85,15 +85,15 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   files:
   - provider_id: meta-reference-files
     provider_type: inline::localfs
     config:
-      storage_dir: ${env.FILES_STORAGE_DIR:~/.llama/distributions/ollama/files}
+      storage_dir: ${env.FILES_STORAGE_DIR:=~/.llama/distributions/ollama/files}
       metadata_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/files_metadata.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/files_metadata.db
   post_training:
   - provider_id: huggingface
     provider_type: inline::huggingface
@@ -105,12 +105,12 @@ providers:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -121,13 +121,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/ollama/run.yaml b/llama_stack/templates/ollama/run.yaml
index 8c2b17ef1..d2b4e3978 100644
--- a/llama_stack/templates/ollama/run.yaml
+++ b/llama_stack/templates/ollama/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: ollama
 apis:
 - agents
@@ -17,7 +17,7 @@ providers:
   - provider_id: ollama
     provider_type: remote::ollama
     config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
+      url: ${env.OLLAMA_URL:=http://localhost:11434}
       raise_on_connect_error: true
   vector_io:
   - provider_id: faiss
@@ -26,7 +26,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -39,17 +39,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -57,7 +57,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -65,14 +65,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -83,15 +83,15 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   files:
   - provider_id: meta-reference-files
     provider_type: inline::localfs
     config:
-      storage_dir: ${env.FILES_STORAGE_DIR:~/.llama/distributions/ollama/files}
+      storage_dir: ${env.FILES_STORAGE_DIR:=~/.llama/distributions/ollama/files}
       metadata_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/files_metadata.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/files_metadata.db
   post_training:
   - provider_id: huggingface
     provider_type: inline::huggingface
@@ -103,12 +103,12 @@ providers:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -119,13 +119,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/open-benchmark/build.yaml b/llama_stack/templates/open-benchmark/build.yaml
index 840f1e1db..5f82c5243 100644
--- a/llama_stack/templates/open-benchmark/build.yaml
+++ b/llama_stack/templates/open-benchmark/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Distribution for running open benchmarks
   providers:
diff --git a/llama_stack/templates/open-benchmark/open_benchmark.py b/llama_stack/templates/open-benchmark/open_benchmark.py
index f0738ae5b..b4cfbdb52 100644
--- a/llama_stack/templates/open-benchmark/open_benchmark.py
+++ b/llama_stack/templates/open-benchmark/open_benchmark.py
@@ -120,17 +120,17 @@ def get_distribution_template() -> DistributionTemplate:
             config=SQLiteVectorIOConfig.sample_run_config(f"~/.llama/distributions/{name}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_CHROMADB+chromadb}",
+            provider_id="${env.ENABLE_CHROMADB:+chromadb}",
             provider_type="remote::chromadb",
-            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:}"),
+            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:+}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_PGVECTOR+pgvector}",
+            provider_id="${env.ENABLE_PGVECTOR:+pgvector}",
             provider_type="remote::pgvector",
             config=PGVectorVectorIOConfig.sample_run_config(
-                db="${env.PGVECTOR_DB:}",
-                user="${env.PGVECTOR_USER:}",
-                password="${env.PGVECTOR_PASSWORD:}",
+                db="${env.PGVECTOR_DB:+}",
+                user="${env.PGVECTOR_USER:+}",
+                password="${env.PGVECTOR_PASSWORD:+}",
             ),
         ),
     ]
diff --git a/llama_stack/templates/open-benchmark/run.yaml b/llama_stack/templates/open-benchmark/run.yaml
index 051ca6f8e..403b0fd3d 100644
--- a/llama_stack/templates/open-benchmark/run.yaml
+++ b/llama_stack/templates/open-benchmark/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: open-benchmark
 apis:
 - agents
@@ -33,24 +33,24 @@ providers:
     provider_type: remote::together
     config:
       url: https://api.together.xyz/v1
-      api_key: ${env.TOGETHER_API_KEY:}
+      api_key: ${env.TOGETHER_API_KEY:+}
   vector_io:
   - provider_id: sqlite-vec
     provider_type: inline::sqlite-vec
     config:
-      db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/sqlite_vec.db
-  - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/sqlite_vec.db
+  - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
     provider_type: remote::chromadb
     config:
-      url: ${env.CHROMADB_URL:}
-  - provider_id: ${env.ENABLE_PGVECTOR+pgvector}
+      url: ${env.CHROMADB_URL:+}
+  - provider_id: ${env.ENABLE_PGVECTOR:+pgvector}
     provider_type: remote::pgvector
     config:
-      host: ${env.PGVECTOR_HOST:localhost}
-      port: ${env.PGVECTOR_PORT:5432}
-      db: ${env.PGVECTOR_DB:}
-      user: ${env.PGVECTOR_USER:}
-      password: ${env.PGVECTOR_PASSWORD:}
+      host: ${env.PGVECTOR_HOST:=localhost}
+      port: ${env.PGVECTOR_PORT:=5432}
+      db: ${env.PGVECTOR_DB:+}
+      user: ${env.PGVECTOR_USER:+}
+      password: ${env.PGVECTOR_PASSWORD:+}
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -63,17 +63,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -81,7 +81,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -89,14 +89,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -107,17 +107,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -127,10 +127,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/open-benchmark}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/open-benchmark}/inference_store.db
 models:
 - metadata: {}
   model_id: openai/gpt-4o
diff --git a/llama_stack/templates/passthrough/build.yaml b/llama_stack/templates/passthrough/build.yaml
index 46b99cb75..e2e041dbc 100644
--- a/llama_stack/templates/passthrough/build.yaml
+++ b/llama_stack/templates/passthrough/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use Passthrough hosted llama-stack endpoint for LLM inference
   providers:
diff --git a/llama_stack/templates/passthrough/run-with-safety.yaml b/llama_stack/templates/passthrough/run-with-safety.yaml
index 3168eeb9f..c5b047511 100644
--- a/llama_stack/templates/passthrough/run-with-safety.yaml
+++ b/llama_stack/templates/passthrough/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: passthrough
 apis:
 - agents
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -45,17 +45,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -63,7 +63,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -71,14 +71,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -89,22 +89,22 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
@@ -113,10 +113,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/inference_store.db
 models:
 - metadata: {}
   model_id: meta-llama/Llama-3.1-8B-Instruct
diff --git a/llama_stack/templates/passthrough/run.yaml b/llama_stack/templates/passthrough/run.yaml
index 48abf8577..896b3c91e 100644
--- a/llama_stack/templates/passthrough/run.yaml
+++ b/llama_stack/templates/passthrough/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: passthrough
 apis:
 - agents
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,22 +84,22 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
@@ -108,10 +108,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/passthrough}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/passthrough}/inference_store.db
 models:
 - metadata: {}
   model_id: meta-llama/Llama-3.1-8B-Instruct
diff --git a/llama_stack/templates/postgres-demo/build.yaml b/llama_stack/templates/postgres-demo/build.yaml
index 6416cd00f..645b59613 100644
--- a/llama_stack/templates/postgres-demo/build.yaml
+++ b/llama_stack/templates/postgres-demo/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Quick start template for running Llama Stack with several popular providers
   providers:
diff --git a/llama_stack/templates/postgres-demo/postgres_demo.py b/llama_stack/templates/postgres-demo/postgres_demo.py
index a1a2aa2b7..5d42b8901 100644
--- a/llama_stack/templates/postgres-demo/postgres_demo.py
+++ b/llama_stack/templates/postgres-demo/postgres_demo.py
@@ -50,9 +50,9 @@ def get_distribution_template() -> DistributionTemplate:
 
     vector_io_providers = [
         Provider(
-            provider_id="${env.ENABLE_CHROMADB+chromadb}",
+            provider_id="${env.ENABLE_CHROMADB:+chromadb}",
             provider_type="remote::chromadb",
-            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:}"),
+            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:+}"),
         ),
     ]
     default_tool_groups = [
@@ -114,9 +114,9 @@ def get_distribution_template() -> DistributionTemplate:
                             provider_id="meta-reference",
                             provider_type="inline::meta-reference",
                             config=dict(
-                                service_name="${env.OTEL_SERVICE_NAME:}",
-                                sinks="${env.TELEMETRY_SINKS:console,otel_trace}",
-                                otel_trace_endpoint="${env.OTEL_TRACE_ENDPOINT:http://localhost:4318/v1/traces}",
+                                service_name="${env.OTEL_SERVICE_NAME:+}",
+                                sinks="${env.TELEMETRY_SINKS:=console,otel_trace}",
+                                otel_trace_endpoint="${env.OTEL_TRACE_ENDPOINT:=http://localhost:4318/v1/traces}",
                             ),
                         )
                     ],
diff --git a/llama_stack/templates/postgres-demo/run.yaml b/llama_stack/templates/postgres-demo/run.yaml
index 0e0d020b2..03b7a59fb 100644
--- a/llama_stack/templates/postgres-demo/run.yaml
+++ b/llama_stack/templates/postgres-demo/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: postgres-demo
 apis:
 - agents
@@ -13,17 +13,17 @@ providers:
     provider_type: remote::vllm
     config:
       url: ${env.VLLM_URL:http://localhost:8000/v1}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
   vector_io:
-  - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+  - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
     provider_type: remote::chromadb
     config:
-      url: ${env.CHROMADB_URL:}
+      url: ${env.CHROMADB_URL:+}
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -35,35 +35,35 @@ providers:
     config:
       persistence_store:
         type: postgres
-        host: ${env.POSTGRES_HOST:localhost}
-        port: ${env.POSTGRES_PORT:5432}
-        db: ${env.POSTGRES_DB:llamastack}
-        user: ${env.POSTGRES_USER:llamastack}
-        password: ${env.POSTGRES_PASSWORD:llamastack}
+        host: ${env.POSTGRES_HOST:=localhost}
+        port: ${env.POSTGRES_PORT:=5432}
+        db: ${env.POSTGRES_DB:=llamastack}
+        user: ${env.POSTGRES_USER:=llamastack}
+        password: ${env.POSTGRES_PASSWORD:=llamastack}
       responses_store:
         type: postgres
-        host: ${env.POSTGRES_HOST:localhost}
-        port: ${env.POSTGRES_PORT:5432}
-        db: ${env.POSTGRES_DB:llamastack}
-        user: ${env.POSTGRES_USER:llamastack}
-        password: ${env.POSTGRES_PASSWORD:llamastack}
+        host: ${env.POSTGRES_HOST:=localhost}
+        port: ${env.POSTGRES_PORT:=5432}
+        db: ${env.POSTGRES_DB:=llamastack}
+        user: ${env.POSTGRES_USER:=llamastack}
+        password: ${env.POSTGRES_PASSWORD:=llamastack}
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: ${env.OTEL_SERVICE_NAME:}
-      sinks: ${env.TELEMETRY_SINKS:console,otel_trace}
-      otel_trace_endpoint: ${env.OTEL_TRACE_ENDPOINT:http://localhost:4318/v1/traces}
+      service_name: ${env.OTEL_SERVICE_NAME:+}
+      sinks: ${env.TELEMETRY_SINKS:=console,otel_trace}
+      otel_trace_endpoint: ${env.OTEL_TRACE_ENDPOINT:=http://localhost:4318/v1/traces}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -73,19 +73,19 @@ providers:
     config: {}
 metadata_store:
   type: postgres
-  host: ${env.POSTGRES_HOST:localhost}
-  port: ${env.POSTGRES_PORT:5432}
-  db: ${env.POSTGRES_DB:llamastack}
-  user: ${env.POSTGRES_USER:llamastack}
-  password: ${env.POSTGRES_PASSWORD:llamastack}
-  table_name: ${env.POSTGRES_TABLE_NAME:llamastack_kvstore}
+  host: ${env.POSTGRES_HOST:=localhost}
+  port: ${env.POSTGRES_PORT:=5432}
+  db: ${env.POSTGRES_DB:=llamastack}
+  user: ${env.POSTGRES_USER:=llamastack}
+  password: ${env.POSTGRES_PASSWORD:=llamastack}
+  table_name: ${env.POSTGRES_TABLE_NAME:=llamastack_kvstore}
 inference_store:
   type: postgres
-  host: ${env.POSTGRES_HOST:localhost}
-  port: ${env.POSTGRES_PORT:5432}
-  db: ${env.POSTGRES_DB:llamastack}
-  user: ${env.POSTGRES_USER:llamastack}
-  password: ${env.POSTGRES_PASSWORD:llamastack}
+  host: ${env.POSTGRES_HOST:=localhost}
+  port: ${env.POSTGRES_PORT:=5432}
+  db: ${env.POSTGRES_DB:=llamastack}
+  user: ${env.POSTGRES_USER:=llamastack}
+  password: ${env.POSTGRES_PASSWORD:=llamastack}
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/remote-vllm/build.yaml b/llama_stack/templates/remote-vllm/build.yaml
index 16fe5d4fd..0298b01c7 100644
--- a/llama_stack/templates/remote-vllm/build.yaml
+++ b/llama_stack/templates/remote-vllm/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use (an external) vLLM server for running LLM inference
   providers:
diff --git a/llama_stack/templates/remote-vllm/run-with-safety.yaml b/llama_stack/templates/remote-vllm/run-with-safety.yaml
index 64f71087a..b297f1489 100644
--- a/llama_stack/templates/remote-vllm/run-with-safety.yaml
+++ b/llama_stack/templates/remote-vllm/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: remote-vllm
 apis:
 - agents
@@ -16,16 +16,16 @@ providers:
     provider_type: remote::vllm
     config:
       url: ${env.VLLM_URL:http://localhost:8000/v1}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: vllm-safety
     provider_type: remote::vllm
     config:
       url: ${env.SAFETY_VLLM_URL}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -36,7 +36,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -49,10 +49,10 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/responses_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -60,7 +60,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -68,14 +68,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -86,24 +86,24 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/trace_store.db
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -114,13 +114,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/remote-vllm/run.yaml b/llama_stack/templates/remote-vllm/run.yaml
index 353b9902d..6bd332cc9 100644
--- a/llama_stack/templates/remote-vllm/run.yaml
+++ b/llama_stack/templates/remote-vllm/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: remote-vllm
 apis:
 - agents
@@ -16,9 +16,9 @@ providers:
     provider_type: remote::vllm
     config:
       url: ${env.VLLM_URL:http://localhost:8000/v1}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -29,7 +29,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -42,10 +42,10 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/responses_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -53,7 +53,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -61,14 +61,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -79,24 +79,24 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/trace_store.db
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -107,13 +107,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/remote-vllm}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/remote-vllm}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/sambanova/build.yaml b/llama_stack/templates/sambanova/build.yaml
index 14b1c8974..ba70f88c6 100644
--- a/llama_stack/templates/sambanova/build.yaml
+++ b/llama_stack/templates/sambanova/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use SambaNova for running LLM inference and safety
   providers:
diff --git a/llama_stack/templates/sambanova/run.yaml b/llama_stack/templates/sambanova/run.yaml
index 58d0d36e3..b96621b58 100644
--- a/llama_stack/templates/sambanova/run.yaml
+++ b/llama_stack/templates/sambanova/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: sambanova
 apis:
 - agents
@@ -24,19 +24,19 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/sambanova}/faiss_store.db
-  - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/sambanova}/faiss_store.db
+  - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
     provider_type: remote::chromadb
     config:
-      url: ${env.CHROMADB_URL:}
-  - provider_id: ${env.ENABLE_PGVECTOR+pgvector}
+      url: ${env.CHROMADB_URL:+}
+  - provider_id: ${env.ENABLE_PGVECTOR:+pgvector}
     provider_type: remote::pgvector
     config:
-      host: ${env.PGVECTOR_HOST:localhost}
-      port: ${env.PGVECTOR_PORT:5432}
-      db: ${env.PGVECTOR_DB:}
-      user: ${env.PGVECTOR_USER:}
-      password: ${env.PGVECTOR_PASSWORD:}
+      host: ${env.PGVECTOR_HOST:=localhost}
+      port: ${env.PGVECTOR_PORT:=5432}
+      db: ${env.PGVECTOR_DB:+}
+      user: ${env.PGVECTOR_USER:+}
+      password: ${env.PGVECTOR_PASSWORD:+}
   safety:
   - provider_id: sambanova
     provider_type: remote::sambanova
@@ -50,27 +50,27 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/sambanova}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/sambanova}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/sambanova}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/sambanova}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/sambanova}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/sambanova}/trace_store.db
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -81,13 +81,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/sambanova}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/sambanova}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/sambanova}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/sambanova}/inference_store.db
 models:
 - metadata: {}
   model_id: sambanova/Meta-Llama-3.1-8B-Instruct
diff --git a/llama_stack/templates/sambanova/sambanova.py b/llama_stack/templates/sambanova/sambanova.py
index 38df6a4be..428577697 100644
--- a/llama_stack/templates/sambanova/sambanova.py
+++ b/llama_stack/templates/sambanova/sambanova.py
@@ -73,17 +73,17 @@ def get_distribution_template() -> DistributionTemplate:
             ),
         ),
         Provider(
-            provider_id="${env.ENABLE_CHROMADB+chromadb}",
+            provider_id="${env.ENABLE_CHROMADB:+chromadb}",
             provider_type="remote::chromadb",
-            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:}"),
+            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:+}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_PGVECTOR+pgvector}",
+            provider_id="${env.ENABLE_PGVECTOR:+pgvector}",
             provider_type="remote::pgvector",
             config=PGVectorVectorIOConfig.sample_run_config(
-                db="${env.PGVECTOR_DB:}",
-                user="${env.PGVECTOR_USER:}",
-                password="${env.PGVECTOR_PASSWORD:}",
+                db="${env.PGVECTOR_DB:+}",
+                user="${env.PGVECTOR_USER:+}",
+                password="${env.PGVECTOR_PASSWORD:+}",
             ),
         ),
     ]
diff --git a/llama_stack/templates/starter/build.yaml b/llama_stack/templates/starter/build.yaml
index 9bf4913a7..3b48dcf7a 100644
--- a/llama_stack/templates/starter/build.yaml
+++ b/llama_stack/templates/starter/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Quick start template for running Llama Stack with several popular providers
   providers:
diff --git a/llama_stack/templates/starter/run.yaml b/llama_stack/templates/starter/run.yaml
index 30df39e5d..f7c53170b 100644
--- a/llama_stack/templates/starter/run.yaml
+++ b/llama_stack/templates/starter/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: starter
 apis:
 - agents
@@ -16,47 +16,47 @@ providers:
   - provider_id: openai
     provider_type: remote::openai
     config:
-      api_key: ${env.OPENAI_API_KEY:}
+      api_key: ${env.OPENAI_API_KEY:+}
   - provider_id: fireworks
     provider_type: remote::fireworks
     config:
       url: https://api.fireworks.ai/inference/v1
-      api_key: ${env.FIREWORKS_API_KEY:}
+      api_key: ${env.FIREWORKS_API_KEY:+}
   - provider_id: together
     provider_type: remote::together
     config:
       url: https://api.together.xyz/v1
-      api_key: ${env.TOGETHER_API_KEY:}
+      api_key: ${env.TOGETHER_API_KEY:+}
   - provider_id: ollama
     provider_type: remote::ollama
     config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
+      url: ${env.OLLAMA_URL:=http://localhost:11434}
       raise_on_connect_error: false
   - provider_id: anthropic
     provider_type: remote::anthropic
     config:
-      api_key: ${env.ANTHROPIC_API_KEY:}
+      api_key: ${env.ANTHROPIC_API_KEY:+}
   - provider_id: gemini
     provider_type: remote::gemini
     config:
-      api_key: ${env.GEMINI_API_KEY:}
+      api_key: ${env.GEMINI_API_KEY:+}
   - provider_id: groq
     provider_type: remote::groq
     config:
       url: https://api.groq.com
-      api_key: ${env.GROQ_API_KEY:}
+      api_key: ${env.GROQ_API_KEY:+}
   - provider_id: sambanova
     provider_type: remote::sambanova
     config:
       url: https://api.sambanova.ai/v1
-      api_key: ${env.SAMBANOVA_API_KEY:}
+      api_key: ${env.SAMBANOVA_API_KEY:+}
   - provider_id: vllm
     provider_type: remote::vllm
     config:
-      url: ${env.VLLM_URL:http://localhost:8000/v1}
-      max_tokens: ${env.VLLM_MAX_TOKENS:4096}
-      api_token: ${env.VLLM_API_TOKEN:fake}
-      tls_verify: ${env.VLLM_TLS_VERIFY:true}
+      url: ${env.VLLM_URL:=http://localhost:8000/v1}
+      max_tokens: ${env.VLLM_MAX_TOKENS:=4096}
+      api_token: ${env.VLLM_API_TOKEN:=fake}
+      tls_verify: ${env.VLLM_TLS_VERIFY:=true}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -67,31 +67,31 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/faiss_store.db
   - provider_id: ${env.ENABLE_SQLITE_VEC+sqlite-vec}
     provider_type: inline::sqlite-vec
     config:
-      db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/sqlite_vec.db
-  - provider_id: ${env.ENABLE_CHROMADB+chromadb}
+      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/sqlite_vec.db
+  - provider_id: ${env.ENABLE_CHROMADB:+chromadb}
     provider_type: remote::chromadb
     config:
-      url: ${env.CHROMADB_URL:}
-  - provider_id: ${env.ENABLE_PGVECTOR+pgvector}
+      url: ${env.CHROMADB_URL:+}
+  - provider_id: ${env.ENABLE_PGVECTOR:+pgvector}
     provider_type: remote::pgvector
     config:
-      host: ${env.PGVECTOR_HOST:localhost}
-      port: ${env.PGVECTOR_PORT:5432}
-      db: ${env.PGVECTOR_DB:}
-      user: ${env.PGVECTOR_USER:}
-      password: ${env.PGVECTOR_PASSWORD:}
+      host: ${env.PGVECTOR_HOST:=localhost}
+      port: ${env.PGVECTOR_PORT:=5432}
+      db: ${env.PGVECTOR_DB:+}
+      user: ${env.PGVECTOR_USER:+}
+      password: ${env.PGVECTOR_PASSWORD:+}
   files:
   - provider_id: meta-reference-files
     provider_type: inline::localfs
     config:
-      storage_dir: ${env.FILES_STORAGE_DIR:~/.llama/distributions/starter/files}
+      storage_dir: ${env.FILES_STORAGE_DIR:=~/.llama/distributions/starter/files}
       metadata_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/files_metadata.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/files_metadata.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -104,17 +104,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -122,7 +122,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -130,14 +130,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -148,17 +148,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -168,10 +168,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/starter}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter}/inference_store.db
 models:
 - metadata: {}
   model_id: openai/gpt-4o
@@ -538,15 +538,15 @@ models:
   provider_model_id: meta-llama/Llama-4-Maverick-17B-128E-Instruct-FP8
   model_type: llm
 - metadata: {}
-  model_id: ollama/${env.OLLAMA_INFERENCE_MODEL:__disabled__}
+  model_id: ollama/${env.OLLAMA_INFERENCE_MODEL:=__disabled__}
   provider_id: ollama
-  provider_model_id: ${env.OLLAMA_INFERENCE_MODEL:__disabled__}
+  provider_model_id: ${env.OLLAMA_INFERENCE_MODEL:=__disabled__}
   model_type: llm
 - metadata:
-    embedding_dimension: ${env.OLLAMA_EMBEDDING_DIMENSION:384}
-  model_id: ollama/${env.OLLAMA_EMBEDDING_MODEL:__disabled__}
+    embedding_dimension: ${env.OLLAMA_EMBEDDING_DIMENSION:=384}
+  model_id: ollama/${env.OLLAMA_EMBEDDING_MODEL:=__disabled__}
   provider_id: ollama
-  provider_model_id: ${env.OLLAMA_EMBEDDING_MODEL:__disabled__}
+  provider_model_id: ${env.OLLAMA_EMBEDDING_MODEL:=__disabled__}
   model_type: embedding
 - metadata: {}
   model_id: anthropic/claude-3-5-sonnet-latest
@@ -802,9 +802,9 @@ models:
   provider_model_id: sambanova/Meta-Llama-Guard-3-8B
   model_type: llm
 - metadata: {}
-  model_id: vllm/${env.VLLM_INFERENCE_MODEL:__disabled__}
+  model_id: vllm/${env.VLLM_INFERENCE_MODEL:=__disabled__}
   provider_id: vllm
-  provider_model_id: ${env.VLLM_INFERENCE_MODEL:__disabled__}
+  provider_model_id: ${env.VLLM_INFERENCE_MODEL:=__disabled__}
   model_type: llm
 - metadata:
     embedding_dimension: 384
diff --git a/llama_stack/templates/starter/starter.py b/llama_stack/templates/starter/starter.py
index 8e111e80a..df31fed84 100644
--- a/llama_stack/templates/starter/starter.py
+++ b/llama_stack/templates/starter/starter.py
@@ -69,67 +69,67 @@ def get_inference_providers() -> tuple[list[Provider], dict[str, list[ProviderMo
         (
             "openai",
             OPENAI_MODEL_ENTRIES,
-            OpenAIConfig.sample_run_config(api_key="${env.OPENAI_API_KEY:}"),
+            OpenAIConfig.sample_run_config(api_key="${env.OPENAI_API_KEY:+}"),
         ),
         (
             "fireworks",
             FIREWORKS_MODEL_ENTRIES,
-            FireworksImplConfig.sample_run_config(api_key="${env.FIREWORKS_API_KEY:}"),
+            FireworksImplConfig.sample_run_config(api_key="${env.FIREWORKS_API_KEY:+}"),
         ),
         (
             "together",
             TOGETHER_MODEL_ENTRIES,
-            TogetherImplConfig.sample_run_config(api_key="${env.TOGETHER_API_KEY:}"),
+            TogetherImplConfig.sample_run_config(api_key="${env.TOGETHER_API_KEY:+}"),
         ),
         (
             "ollama",
             [
                 ProviderModelEntry(
-                    provider_model_id="${env.OLLAMA_INFERENCE_MODEL:__disabled__}",
+                    provider_model_id="${env.OLLAMA_INFERENCE_MODEL:=__disabled__}",
                     model_type=ModelType.llm,
                 ),
                 ProviderModelEntry(
-                    provider_model_id="${env.OLLAMA_EMBEDDING_MODEL:__disabled__}",
+                    provider_model_id="${env.OLLAMA_EMBEDDING_MODEL:=__disabled__}",
                     model_type=ModelType.embedding,
                     metadata={
-                        "embedding_dimension": "${env.OLLAMA_EMBEDDING_DIMENSION:384}",
+                        "embedding_dimension": "${env.OLLAMA_EMBEDDING_DIMENSION:=384}",
                     },
                 ),
             ],
             OllamaImplConfig.sample_run_config(
-                url="${env.OLLAMA_URL:http://localhost:11434}", raise_on_connect_error=False
+                url="${env.OLLAMA_URL:=http://localhost:11434}", raise_on_connect_error=False
             ),
         ),
         (
             "anthropic",
             ANTHROPIC_MODEL_ENTRIES,
-            AnthropicConfig.sample_run_config(api_key="${env.ANTHROPIC_API_KEY:}"),
+            AnthropicConfig.sample_run_config(api_key="${env.ANTHROPIC_API_KEY:+}"),
         ),
         (
             "gemini",
             GEMINI_MODEL_ENTRIES,
-            GeminiConfig.sample_run_config(api_key="${env.GEMINI_API_KEY:}"),
+            GeminiConfig.sample_run_config(api_key="${env.GEMINI_API_KEY:+}"),
         ),
         (
             "groq",
             GROQ_MODEL_ENTRIES,
-            GroqConfig.sample_run_config(api_key="${env.GROQ_API_KEY:}"),
+            GroqConfig.sample_run_config(api_key="${env.GROQ_API_KEY:+}"),
         ),
         (
             "sambanova",
             SAMBANOVA_MODEL_ENTRIES,
-            SambaNovaImplConfig.sample_run_config(api_key="${env.SAMBANOVA_API_KEY:}"),
+            SambaNovaImplConfig.sample_run_config(api_key="${env.SAMBANOVA_API_KEY:+}"),
         ),
         (
             "vllm",
             [
                 ProviderModelEntry(
-                    provider_model_id="${env.VLLM_INFERENCE_MODEL:__disabled__}",
+                    provider_model_id="${env.VLLM_INFERENCE_MODEL:=__disabled__}",
                     model_type=ModelType.llm,
                 ),
             ],
             VLLMInferenceAdapterConfig.sample_run_config(
-                url="${env.VLLM_URL:http://localhost:8000/v1}",
+                url="${env.VLLM_URL:=http://localhost:8000/v1}",
             ),
         ),
     ]
@@ -180,17 +180,17 @@ def get_distribution_template() -> DistributionTemplate:
             config=SQLiteVectorIOConfig.sample_run_config(f"~/.llama/distributions/{name}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_CHROMADB+chromadb}",
+            provider_id="${env.ENABLE_CHROMADB:+chromadb}",
             provider_type="remote::chromadb",
-            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:}"),
+            config=ChromaVectorIOConfig.sample_run_config(url="${env.CHROMADB_URL:+}"),
         ),
         Provider(
-            provider_id="${env.ENABLE_PGVECTOR+pgvector}",
+            provider_id="${env.ENABLE_PGVECTOR:+pgvector}",
             provider_type="remote::pgvector",
             config=PGVectorVectorIOConfig.sample_run_config(
-                db="${env.PGVECTOR_DB:}",
-                user="${env.PGVECTOR_USER:}",
-                password="${env.PGVECTOR_PASSWORD:}",
+                db="${env.PGVECTOR_DB:+}",
+                user="${env.PGVECTOR_USER:+}",
+                password="${env.PGVECTOR_PASSWORD:+}",
             ),
         ),
     ]
diff --git a/llama_stack/templates/tgi/build.yaml b/llama_stack/templates/tgi/build.yaml
index 361b0b680..3ac3968e8 100644
--- a/llama_stack/templates/tgi/build.yaml
+++ b/llama_stack/templates/tgi/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use (an external) TGI server for running LLM inference
   providers:
diff --git a/llama_stack/templates/tgi/run-with-safety.yaml b/llama_stack/templates/tgi/run-with-safety.yaml
index 22b7bcde6..63da62a03 100644
--- a/llama_stack/templates/tgi/run-with-safety.yaml
+++ b/llama_stack/templates/tgi/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: tgi
 apis:
 - agents
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,17 +84,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -104,10 +104,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/tgi/run.yaml b/llama_stack/templates/tgi/run.yaml
index dd012323c..430494121 100644
--- a/llama_stack/templates/tgi/run.yaml
+++ b/llama_stack/templates/tgi/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: tgi
 apis:
 - agents
@@ -26,7 +26,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -39,17 +39,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -57,7 +57,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -65,14 +65,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -83,17 +83,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -103,10 +103,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/tgi}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/tgi}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/together/build.yaml b/llama_stack/templates/together/build.yaml
index 5ffeac873..518a843da 100644
--- a/llama_stack/templates/together/build.yaml
+++ b/llama_stack/templates/together/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use Together.AI for running LLM inference
   providers:
diff --git a/llama_stack/templates/together/run-with-safety.yaml b/llama_stack/templates/together/run-with-safety.yaml
index a24843416..7ae2a1d1a 100644
--- a/llama_stack/templates/together/run-with-safety.yaml
+++ b/llama_stack/templates/together/run-with-safety.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: together
 apis:
 - agents
@@ -16,7 +16,7 @@ providers:
     provider_type: remote::together
     config:
       url: https://api.together.xyz/v1
-      api_key: ${env.TOGETHER_API_KEY:}
+      api_key: ${env.TOGETHER_API_KEY:+}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -45,17 +45,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -63,7 +63,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -71,14 +71,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -89,17 +89,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -110,13 +110,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/inference_store.db
 models:
 - metadata: {}
   model_id: meta-llama/Meta-Llama-3.1-8B-Instruct-Turbo
diff --git a/llama_stack/templates/together/run.yaml b/llama_stack/templates/together/run.yaml
index c71f960bd..dc09aeac9 100644
--- a/llama_stack/templates/together/run.yaml
+++ b/llama_stack/templates/together/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: together
 apis:
 - agents
@@ -16,7 +16,7 @@ providers:
     provider_type: remote::together
     config:
       url: https://api.together.xyz/v1
-      api_key: ${env.TOGETHER_API_KEY:}
+      api_key: ${env.TOGETHER_API_KEY:+}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -27,7 +27,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -40,17 +40,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -58,7 +58,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -66,14 +66,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -84,17 +84,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -105,13 +105,13 @@ providers:
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/together}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/together}/inference_store.db
 models:
 - metadata: {}
   model_id: meta-llama/Meta-Llama-3.1-8B-Instruct-Turbo
diff --git a/llama_stack/templates/vllm-gpu/build.yaml b/llama_stack/templates/vllm-gpu/build.yaml
index d5ff0f1f4..147dca50d 100644
--- a/llama_stack/templates/vllm-gpu/build.yaml
+++ b/llama_stack/templates/vllm-gpu/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use a built-in vLLM engine for running LLM inference
   providers:
diff --git a/llama_stack/templates/vllm-gpu/run.yaml b/llama_stack/templates/vllm-gpu/run.yaml
index 6878c22b2..104b3a239 100644
--- a/llama_stack/templates/vllm-gpu/run.yaml
+++ b/llama_stack/templates/vllm-gpu/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: vllm-gpu
 apis:
 - agents
@@ -15,12 +15,12 @@ providers:
   - provider_id: vllm
     provider_type: inline::vllm
     config:
-      tensor_parallel_size: ${env.TENSOR_PARALLEL_SIZE:1}
-      max_tokens: ${env.MAX_TOKENS:4096}
-      max_model_len: ${env.MAX_MODEL_LEN:4096}
-      max_num_seqs: ${env.MAX_NUM_SEQS:4}
-      enforce_eager: ${env.ENFORCE_EAGER:False}
-      gpu_memory_utilization: ${env.GPU_MEMORY_UTILIZATION:0.3}
+      tensor_parallel_size: ${env.TENSOR_PARALLEL_SIZE:=1}
+      max_tokens: ${env.MAX_TOKENS:=4096}
+      max_model_len: ${env.MAX_MODEL_LEN:=4096}
+      max_num_seqs: ${env.MAX_NUM_SEQS:=4}
+      enforce_eager: ${env.ENFORCE_EAGER:=False}
+      gpu_memory_utilization: ${env.GPU_MEMORY_UTILIZATION:=0.3}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -31,7 +31,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -44,17 +44,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -62,7 +62,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -70,14 +70,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -88,17 +88,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -108,10 +108,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/vllm-gpu}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/vllm-gpu}/inference_store.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/llama_stack/templates/watsonx/build.yaml b/llama_stack/templates/watsonx/build.yaml
index e68ace183..08ee2c5ce 100644
--- a/llama_stack/templates/watsonx/build.yaml
+++ b/llama_stack/templates/watsonx/build.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 distribution_spec:
   description: Use watsonx for running LLM inference
   providers:
diff --git a/llama_stack/templates/watsonx/run.yaml b/llama_stack/templates/watsonx/run.yaml
index d60a87906..678bf72ff 100644
--- a/llama_stack/templates/watsonx/run.yaml
+++ b/llama_stack/templates/watsonx/run.yaml
@@ -1,4 +1,4 @@
-version: '2'
+version: 2
 image_name: watsonx
 apis:
 - agents
@@ -15,9 +15,9 @@ providers:
   - provider_id: watsonx
     provider_type: remote::watsonx
     config:
-      url: ${env.WATSONX_BASE_URL:https://us-south.ml.cloud.ibm.com}
-      api_key: ${env.WATSONX_API_KEY:}
-      project_id: ${env.WATSONX_PROJECT_ID:}
+      url: ${env.WATSONX_BASE_URL:=https://us-south.ml.cloud.ibm.com}
+      api_key: ${env.WATSONX_API_KEY:+}
+      project_id: ${env.WATSONX_PROJECT_ID:+}
   - provider_id: sentence-transformers
     provider_type: inline::sentence-transformers
     config: {}
@@ -28,7 +28,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/faiss_store.db
   safety:
   - provider_id: llama-guard
     provider_type: inline::llama-guard
@@ -41,17 +41,17 @@ providers:
       persistence_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/agents_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/agents_store.db
       responses_store:
         type: sqlite
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/responses_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/trace_store.db
   eval:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -59,7 +59,7 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/meta_reference_eval.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/meta_reference_eval.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
@@ -67,14 +67,14 @@ providers:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
       kvstore:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/localfs_datasetio.db
   scoring:
   - provider_id: basic
     provider_type: inline::basic
@@ -85,17 +85,17 @@ providers:
   - provider_id: braintrust
     provider_type: inline::braintrust
     config:
-      openai_api_key: ${env.OPENAI_API_KEY:}
+      openai_api_key: ${env.OPENAI_API_KEY:+}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
@@ -105,10 +105,10 @@ providers:
     config: {}
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/registry.db
 inference_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/watsonx}/inference_store.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/inference_store.db
 models:
 - metadata: {}
   model_id: meta-llama/llama-3-3-70b-instruct
diff --git a/tests/external-provider/llama-stack-provider-ollama/run.yaml b/tests/external-provider/llama-stack-provider-ollama/run.yaml
index 158f6800f..60cff7503 100644
--- a/tests/external-provider/llama-stack-provider-ollama/run.yaml
+++ b/tests/external-provider/llama-stack-provider-ollama/run.yaml
@@ -1,71 +1,101 @@
-version: '2'
+version: 2
 image_name: ollama
 apis:
+- agents
+- datasetio
+- eval
 - inference
+- safety
+- scoring
 - telemetry
 - tool_runtime
-- datasetio
 - vector_io
+
 providers:
   inference:
-  - provider_id: custom_ollama
-    provider_type: remote::custom_ollama
+  - provider_id: ollama
+    provider_type: remote::ollama
     config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
+      url: ${env.OLLAMA_URL:=http://localhost:11434}
   vector_io:
   - provider_id: faiss
     provider_type: inline::faiss
     config:
-      kvstore:
+      metadata_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/faiss_store.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/faiss_store.db
+  safety:
+  - provider_id: llama-guard
+    provider_type: inline::llama-guard
+    config: {}
+  agents:
+  - provider_id: meta-reference
+    provider_type: inline::meta-reference
+    config:
+      agents_store:
+        type: sqlite
+        namespace: null
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/agents_store.db
+      responses_store:
+        type: sqlite
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/responses_store.db
   telemetry:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
     config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/trace_store.db
+      service_name: "${env.OTEL_SERVICE_NAME:=\u200b}"
+      sinks: ${env.TELEMETRY_SINKS:=console,sqlite}
+      sqlite_db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/trace_store.db
+  eval:
+  - provider_id: meta-reference
+    provider_type: inline::meta-reference
+    config:
+      metadata_store:
+        type: sqlite
+        namespace: null
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/huggingface_datasetio.db
   datasetio:
   - provider_id: huggingface
     provider_type: remote::huggingface
     config:
-      kvstore:
+      metadata_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/huggingface_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/huggingface_datasetio.db
   - provider_id: localfs
     provider_type: inline::localfs
     config:
-      kvstore:
+      metadata_store:
         type: sqlite
         namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/localfs_datasetio.db
+        db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/localfs_datasetio.db
+  scoring:
+  - provider_id: basic
+    provider_type: inline::basic
+    config: {}
   tool_runtime:
   - provider_id: brave-search
     provider_type: remote::brave-search
     config:
-      api_key: ${env.BRAVE_SEARCH_API_KEY:}
+      api_key: ${env.BRAVE_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: tavily-search
     provider_type: remote::tavily-search
     config:
-      api_key: ${env.TAVILY_SEARCH_API_KEY:}
+      api_key: ${env.TAVILY_SEARCH_API_KEY:+}
       max_results: 3
   - provider_id: rag-runtime
     provider_type: inline::rag-runtime
     config: {}
-  - provider_id: model-context-protocol
-    provider_type: remote::model-context-protocol
-    config: {}
   - provider_id: wolfram-alpha
     provider_type: remote::wolfram-alpha
     config:
-      api_key: ${env.WOLFRAM_ALPHA_API_KEY:}
+      api_key: ${env.WOLFRAM_ALPHA_API_KEY:+}
+
 metadata_store:
   type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/registry.db
+  db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/registry.db
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}
diff --git a/tests/unit/server/test_replace_env_vars.py b/tests/unit/server/test_replace_env_vars.py
index 7fcbbfde9..0fb7c395e 100644
--- a/tests/unit/server/test_replace_env_vars.py
+++ b/tests/unit/server/test_replace_env_vars.py
@@ -26,39 +26,44 @@ class TestReplaceEnvVars(unittest.TestCase):
         self.assertEqual(replace_env_vars("${env.TEST_VAR}"), "test_value")
 
     def test_default_value_when_not_set(self):
-        self.assertEqual(replace_env_vars("${env.NOT_SET:default}"), "default")
+        self.assertEqual(replace_env_vars("${env.NOT_SET:=default}"), "default")
 
     def test_default_value_when_set(self):
-        self.assertEqual(replace_env_vars("${env.TEST_VAR:default}"), "test_value")
+        self.assertEqual(replace_env_vars("${env.TEST_VAR:=default}"), "test_value")
 
     def test_default_value_when_empty(self):
-        self.assertEqual(replace_env_vars("${env.EMPTY_VAR:default}"), "default")
+        self.assertEqual(replace_env_vars("${env.EMPTY_VAR:=default}"), "default")
+
+    def test_empty_var_no_default(self):
+        self.assertEqual(replace_env_vars("${env.EMPTY_VAR_NO_DEFAULT:+}"), None)
 
     def test_conditional_value_when_set(self):
-        self.assertEqual(replace_env_vars("${env.TEST_VAR+conditional}"), "conditional")
+        self.assertEqual(replace_env_vars("${env.TEST_VAR:+conditional}"), "conditional")
 
     def test_conditional_value_when_not_set(self):
-        self.assertEqual(replace_env_vars("${env.NOT_SET+conditional}"), "")
+        self.assertEqual(replace_env_vars("${env.NOT_SET:+conditional}"), None)
 
     def test_conditional_value_when_empty(self):
-        self.assertEqual(replace_env_vars("${env.EMPTY_VAR+conditional}"), "")
+        self.assertEqual(replace_env_vars("${env.EMPTY_VAR:+conditional}"), None)
 
     def test_conditional_value_with_zero(self):
-        self.assertEqual(replace_env_vars("${env.ZERO_VAR+conditional}"), "conditional")
+        self.assertEqual(replace_env_vars("${env.ZERO_VAR:+conditional}"), "conditional")
 
     def test_mixed_syntax(self):
-        self.assertEqual(replace_env_vars("${env.TEST_VAR:default} and ${env.NOT_SET+conditional}"), "test_value and ")
         self.assertEqual(
-            replace_env_vars("${env.NOT_SET:default} and ${env.TEST_VAR+conditional}"), "default and conditional"
+            replace_env_vars("${env.TEST_VAR:=default} and ${env.NOT_SET:+conditional}"), "test_value and "
+        )
+        self.assertEqual(
+            replace_env_vars("${env.NOT_SET:=default} and ${env.TEST_VAR:+conditional}"), "default and conditional"
         )
 
     def test_nested_structures(self):
         data = {
-            "key1": "${env.TEST_VAR:default}",
-            "key2": ["${env.NOT_SET:default}", "${env.TEST_VAR+conditional}"],
-            "key3": {"nested": "${env.NOT_SET+conditional}"},
+            "key1": "${env.TEST_VAR:=default}",
+            "key2": ["${env.NOT_SET:=default}", "${env.TEST_VAR:+conditional}"],
+            "key3": {"nested": "${env.NOT_SET:+conditional}"},
         }
-        expected = {"key1": "test_value", "key2": ["default", "conditional"], "key3": {"nested": ""}}
+        expected = {"key1": "test_value", "key2": ["default", "conditional"], "key3": {"nested": None}}
         self.assertEqual(replace_env_vars(data), expected)