Merge f3297c4166 into fa0b0c13d4

.github/workflows/test-external.yml

@@ -1,4 +1,4 @@
-name: Test External Providers
+name: Test External API and Providers
 
 on:
   push:
@@ -11,10 +11,10 @@ on:
       - 'uv.lock'
       - 'pyproject.toml'
       - 'requirements.txt'
-      - '.github/workflows/test-external-providers.yml' # This workflow
+      - '.github/workflows/test-external.yml' # This workflow
 
 jobs:
-  test-external-providers:
+  test-external:
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -28,24 +28,23 @@ jobs:
       - name: Install dependencies
         uses: ./.github/actions/setup-runner
 
-      - name: Apply image type to config file
+      - name: Create API configuration
         run: |
-          yq -i '.image_type = "${{ matrix.image-type }}"' tests/external-provider/llama-stack-provider-ollama/custom-distro.yaml
-          cat tests/external-provider/llama-stack-provider-ollama/custom-distro.yaml
-
-      - name: Setup directory for Ollama custom provider
-        run: |
-          mkdir -p tests/external-provider/llama-stack-provider-ollama/src/
-          cp -a llama_stack/providers/remote/inference/ollama/ tests/external-provider/llama-stack-provider-ollama/src/llama_stack_provider_ollama
+          mkdir -p /home/runner/.llama/apis.d
+          cp tests/external/weather.yaml /home/runner/.llama/apis.d/weather.yaml
 
       - name: Create provider configuration
         run: |
-          mkdir -p /home/runner/.llama/providers.d/remote/inference
-          cp tests/external-provider/llama-stack-provider-ollama/custom_ollama.yaml /home/runner/.llama/providers.d/remote/inference/custom_ollama.yaml
+          mkdir -p /home/runner/.llama/providers.d/remote/weather
+          cp tests/external/kaze.yaml /home/runner/.llama/providers.d/remote/weather/kaze.yaml
+
+      - name: Print distro dependencies
+        run: |
+          USE_COPY_NOT_MOUNT=true LLAMA_STACK_DIR=. llama stack build --config tests/external/build.yaml --print-deps-only
 
       - name: Build distro from config file
         run: |
-          USE_COPY_NOT_MOUNT=true LLAMA_STACK_DIR=. llama stack build --config tests/external-provider/llama-stack-provider-ollama/custom-distro.yaml
+          USE_COPY_NOT_MOUNT=true LLAMA_STACK_DIR=. llama stack build --config tests/external/build.yaml
 
       - name: Start Llama Stack server in background
         if: ${{ matrix.image-type }} == 'venv'
@@ -55,19 +54,22 @@ jobs:
           # Use the virtual environment created by the build step (name comes from build config)
           source ci-test/bin/activate
           uv pip list
-          nohup llama stack run tests/external-provider/llama-stack-provider-ollama/run.yaml --image-type ${{ matrix.image-type }} > server.log 2>&1 &
+          nohup llama stack run tests/external/run-byoa.yaml --image-type ${{ matrix.image-type }} > server.log 2>&1 &
 
       - name: Wait for Llama Stack server to be ready
         run: |
+          echo "Waiting for Llama Stack server..."
           for i in {1..30}; do
-            if ! grep -q "Successfully loaded external provider remote::custom_ollama" server.log; then
-              echo "Waiting for Llama Stack server to load the provider..."
-              sleep 1
-            else
-              echo "Provider loaded"
+            if curl -sSf http://localhost:8321/v1/health | grep -q "OK"; then
+              echo "Llama Stack server is up!"
               exit 0
             fi
+            sleep 1
           done
-          echo "Provider failed to load"
+          echo "Llama Stack server failed to start"
           cat server.log
           exit 1
+
+      - name: Test external API
+        run: |
+          curl -sSf http://localhost:8321/v1/weather/locations

docs/source/apis/external.md

@@ -0,0 +1,392 @@
+# External APIs
+
+Llama Stack supports external APIs that live outside of the main codebase. This allows you to:
+- Create and maintain your own APIs independently
+- Share APIs with others without contributing to the main codebase
+- Keep API-specific code separate from the core Llama Stack code
+
+## Configuration
+
+To enable external APIs, you need to configure the `external_apis_dir` in your Llama Stack configuration. This directory should contain your external API specifications:
+
+```yaml
+external_apis_dir: ~/.llama/apis.d/
+```
+
+## Directory Structure
+
+The external APIs directory should follow this structure:
+
+```
+apis.d/
+  custom_api1.yaml
+  custom_api2.yaml
+```
+
+Each YAML file in these directories defines an API specification.
+
+## API Specification
+
+Here's an example of an external API specification for a weather API:
+
+```yaml
+module: weather
+api_dependencies:
+  - inference
+protocol: WeatherAPI
+name: weather
+pip_packages:
+  - llama-stack-api-weather
+```
+
+### API Specification Fields
+
+- `module`: Python module containing the API implementation
+- `protocol`: Name of the protocol class for the API
+- `name`: Name of the API
+- `pip_packages`: List of pip packages to install the API, typically a single package
+
+## Required Implementation
+
+External APIs must expose a `available_providers()` function in their module that returns a list of provider names:
+
+```python
+# llama_stack_api_weather/api.py
+from llama_stack.providers.datatypes import Api, InlineProviderSpec, ProviderSpec
+
+
+def available_providers() -> list[ProviderSpec]:
+    return [
+        InlineProviderSpec(
+            api=Api.weather,
+            provider_type="inline::darksky",
+            pip_packages=[],
+            module="llama_stack_provider_darksky",
+            config_class="llama_stack_provider_darksky.DarkSkyWeatherImplConfig",
+        ),
+    ]
+```
+
+A Protocol class like so:
+
+```python
+# llama_stack_api_weather/api.py
+from typing import Protocol
+
+from llama_stack.schema_utils import webmethod
+
+
+class WeatherAPI(Protocol):
+    """
+    A protocol for the Weather API.
+    """
+
+    @webmethod(route="/locations", method="GET")
+    async def get_available_locations() -> dict[str, list[str]]:
+        """
+        Get the available locations.
+        """
+        ...
+```
+
+## Example: Custom API
+
+Here's a complete example of creating and using a custom API:
+
+1. First, create the API package:
+
+```bash
+mkdir -p llama-stack-api-weather
+cd llama-stack-api-weather
+mkdir src/llama_stack_api_weather
+git init
+uv init
+```
+
+2. Edit `pyproject.toml`:
+
+```toml
+[project]
+name = "llama-stack-api-weather"
+version = "0.1.0"
+description = "Weather API for Llama Stack"
+readme = "README.md"
+requires-python = ">=3.10"
+dependencies = ["llama-stack", "pydantic"]
+
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+include = ["llama_stack_api_weather", "llama_stack_api_weather.*"]
+```
+
+3. Create the initial files:
+
+```bash
+touch src/llama_stack_api_weather/__init__.py
+touch src/llama_stack_api_weather/api.py
+```
+
+```python
+# llama-stack-api-weather/src/llama_stack_api_weather/__init__.py
+"""Weather API for Llama Stack."""
+
+from .api import WeatherAPI, available_providers
+
+__all__ = ["WeatherAPI", "available_providers"]
+```
+
+4. Create the API implementation:
+
+```python
+# llama-stack-api-weather/src/llama_stack_api_weather/weather.py
+from typing import Protocol
+
+from llama_stack.providers.datatypes import (
+    AdapterSpec,
+    Api,
+    ProviderSpec,
+    RemoteProviderSpec,
+)
+from llama_stack.schema_utils import webmethod
+
+
+def available_providers() -> list[ProviderSpec]:
+    return [
+        RemoteProviderSpec(
+            api=Api.weather,
+            provider_type="remote::kaze",
+            config_class="llama_stack_provider_kaze.KazeProviderConfig",
+            adapter=AdapterSpec(
+                adapter_type="kaze",
+                module="llama_stack_provider_kaze",
+                pip_packages=["llama_stack_provider_kaze"],
+                config_class="llama_stack_provider_kaze.KazeProviderConfig",
+            ),
+        ),
+    ]
+
+
+class WeatherProvider(Protocol):
+    """
+    A protocol for the Weather API.
+    """
+
+    @webmethod(route="/weather/locations", method="GET")
+    async def get_available_locations() -> dict[str, list[str]]:
+        """
+        Get the available locations.
+        """
+        ...
+```
+
+5. Create the API specification:
+
+```yaml
+# ~/.llama/apis.d/weather.yaml
+module: llama_stack_api_weather
+name: weather
+pip_packages: ["llama-stack-api-weather"]
+protocol: WeatherProvider
+
+```
+
+6. Install the API package:
+
+```bash
+uv pip install -e .
+```
+
+7. Configure Llama Stack to use external APIs:
+
+```yaml
+version: "2"
+image_name: "llama-stack-api-weather"
+apis:
+  - weather
+providers: {}
+external_apis_dir: ~/.llama/apis.d
+```
+
+The API will now be available at `/v1/weather/locations`.
+
+## Example: custom provider for the weather API
+
+1. Create the provider package:
+
+```bash
+mkdir -p llama-stack-provider-kaze
+cd llama-stack-provider-kaze
+uv init
+```
+
+2. Edit `pyproject.toml`:
+
+```toml
+[project]
+name = "llama-stack-provider-kaze"
+version = "0.1.0"
+description = "Kaze weather provider for Llama Stack"
+readme = "README.md"
+requires-python = ">=3.10"
+dependencies = ["llama-stack", "pydantic", "aiohttp"]
+
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+include = ["llama_stack_provider_kaze", "llama_stack_provider_kaze.*"]
+```
+
+3. Create the initial files:
+
+```bash
+touch src/llama_stack_provider_kaze/__init__.py
+touch src/llama_stack_provider_kaze/kaze.py
+```
+
+4. Create the provider implementation:
+
+
+Initialization function:
+
+```python
+# llama-stack-provider-kaze/src/llama_stack_provider_kaze/__init__.py
+"""Kaze weather provider for Llama Stack."""
+
+from .config import KazeProviderConfig
+from .kaze import WeatherKazeAdapter
+
+__all__ = ["KazeProviderConfig", "WeatherKazeAdapter"]
+
+
+async def get_adapter_impl(config: KazeProviderConfig, _deps):
+    from .kaze import WeatherKazeAdapter
+
+    impl = WeatherKazeAdapter(config)
+    await impl.initialize()
+    return impl
+```
+
+Configuration:
+
+```python
+# llama-stack-provider-kaze/src/llama_stack_provider_kaze/config.py
+from pydantic import BaseModel, Field
+
+
+class KazeProviderConfig(BaseModel):
+    """Configuration for the Kaze weather provider."""
+
+    base_url: str = Field(
+        "https://api.kaze.io/v1",
+        description="Base URL for the Kaze weather API",
+    )
+```
+
+Main implementation:
+
+```python
+# llama-stack-provider-kaze/src/llama_stack_provider_kaze/kaze.py
+from llama_stack_api_weather.api import WeatherProvider
+
+from .config import KazeProviderConfig
+
+
+class WeatherKazeAdapter(WeatherProvider):
+    """Kaze weather provider implementation."""
+
+    def __init__(
+        self,
+        config: KazeProviderConfig,
+    ) -> None:
+        self.config = config
+
+    async def initialize(self) -> None:
+        pass
+
+    async def get_available_locations(self) -> dict[str, list[str]]:
+        """Get available weather locations."""
+        return {"locations": ["Paris", "Tokyo"]}
+```
+
+5. Create the provider specification:
+
+```yaml
+# ~/.llama/providers.d/remote/weather/kaze.yaml
+adapter:
+  adapter_type: kaze
+  pip_packages: ["llama_stack_provider_kaze"]
+  config_class: llama_stack_provider_kaze.config.KazeProviderConfig
+  module: llama_stack_provider_kaze
+optional_api_dependencies: []
+```
+
+6. Install the provider package:
+
+```bash
+uv pip install -e .
+```
+
+7. Configure Llama Stack to use the provider:
+
+```yaml
+# ~/.llama/run-byoa.yaml
+version: "2"
+image_name: "llama-stack-api-weather"
+apis:
+  - weather
+providers:
+  weather:
+  - provider_id: kaze
+    provider_type: remote::kaze
+    config: {}
+external_apis_dir: ~/.llama/apis.d
+external_providers_dir: ~/.llama/providers.d
+server:
+  port: 8321
+```
+
+8. Run the server:
+
+```bash
+python -m llama_stack.distribution.server.server --yaml-config ~/.llama/run-byoa.yaml
+```
+
+9. Test the API:
+
+```bash
+curl -sSf http://127.0.0.1:8321/v1/weather/locations
+{"locations":["Paris","Tokyo"]}%
+```
+
+## Best Practices
+
+1. **Package Naming**: Use a clear and descriptive name for your API package.
+
+2. **Version Management**: Keep your API package versioned and compatible with the Llama Stack version you're using.
+
+3. **Dependencies**: Only include the minimum required dependencies in your API package.
+
+4. **Documentation**: Include clear documentation in your API package about:
+   - Installation requirements
+   - Configuration options
+   - API endpoints and usage
+   - Any limitations or known issues
+
+5. **Testing**: Include tests in your API package to ensure it works correctly with Llama Stack.
+
+## Troubleshooting
+
+If your external API isn't being loaded:
+
+1. Check that the `external_apis_dir` path is correct and accessible.
+2. Verify that the YAML files are properly formatted.
+3. Ensure all required Python packages are installed.
+4. Check the Llama Stack server logs for any error messages - turn on debug logging to get more information using `LLAMA_STACK_LOGGING=all=debug`.
+5. Verify that the API package is installed in your Python environment.

llama_stack/apis/datatypes.py

@@ -4,15 +4,83 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 
-from enum import Enum
+from enum import Enum, EnumMeta
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 from llama_stack.schema_utils import json_schema_type
 
 
+class DynamicApiMeta(EnumMeta):
+    def __new__(cls, name, bases, namespace):
+        # Store the original enum values
+        original_values = {k: v for k, v in namespace.items() if not k.startswith("_")}
+
+        # Create the enum class
+        cls = super().__new__(cls, name, bases, namespace)
+
+        # Store the original values for reference
+        cls._original_values = original_values
+        # Initialize _dynamic_values
+        cls._dynamic_values = {}
+
+        return cls
+
+    def __call__(cls, value):
+        try:
+            return super().__call__(value)
+        except ValueError as e:
+            # If this value was already dynamically added, return it
+            if value in cls._dynamic_values:
+                return cls._dynamic_values[value]
+
+            # If the value doesn't exist, create a new enum member
+            # Create a new member name from the value
+            member_name = value.lower().replace("-", "_")
+
+            # If this member name already exists in the enum, return the existing member
+            if member_name in cls._member_map_:
+                return cls._member_map_[member_name]
+
+            # Instead of creating a new member, raise ValueError to force users to use Api.add() to
+            # register new APIs explicitly
+            raise ValueError(f"API '{value}' does not exist. Use Api.add() to register new APIs.") from e
+
+    def __iter__(cls):
+        # Allow iteration over both static and dynamic members
+        yield from super().__iter__()
+        if hasattr(cls, "_dynamic_values"):
+            yield from cls._dynamic_values.values()
+
+    def add(cls, value):
+        """
+        Add a new API to the enum.
+        Used to register external APIs.
+        """
+        member_name = value.lower().replace("-", "_")
+
+        # If this member name already exists in the enum, return it
+        if member_name in cls._member_map_:
+            return cls._member_map_[member_name]
+
+        # Create a new enum member
+        member = object.__new__(cls)
+        member._name_ = member_name
+        member._value_ = value
+
+        # Add it to the enum class
+        cls._member_map_[member_name] = member
+        cls._member_names_.append(member_name)
+        cls._member_type_ = str
+
+        # Store it in our dynamic values
+        cls._dynamic_values[value] = member
+
+        return member
+
+
 @json_schema_type
-class Api(Enum):
+class Api(Enum, metaclass=DynamicApiMeta):
     providers = "providers"
     inference = "inference"
     safety = "safety"
@@ -54,3 +122,12 @@ class Error(BaseModel):
     title: str
     detail: str
     instance: str | None = None
+
+
+class ExternalApiSpec(BaseModel):
+    """Specification for an external API implementation."""
+
+    module: str = Field(..., description="Python module containing the API implementation")
+    name: str = Field(..., description="Name of the API")
+    pip_packages: list[str] = Field(default=[], description="List of pip packages to install the API")
+    protocol: str = Field(..., description="Name of the protocol class for the API")

llama_stack/cli/stack/_build.py

@@ -36,6 +36,7 @@ from llama_stack.distribution.datatypes import (
     StackRunConfig,
 )
 from llama_stack.distribution.distribution import get_provider_registry
+from llama_stack.distribution.external import load_external_apis
 from llama_stack.distribution.resolver import InvalidProviderError
 from llama_stack.distribution.stack import replace_env_vars
 from llama_stack.distribution.utils.config_dirs import DISTRIBS_BASE_DIR, EXTERNAL_PROVIDERS_DIR
@@ -390,6 +391,29 @@ def _run_stack_build_command_from_build_config(
         to_write = json.loads(build_config.model_dump_json())
         f.write(yaml.dump(to_write, sort_keys=False))
 
+    # We first install the external APIs so that the build process can use them and discover the
+    # providers dependencies
+    if build_config.external_apis_dir:
+        cprint("Installing external APIs", color="yellow", file=sys.stderr)
+        external_apis = load_external_apis(build_config)
+        if external_apis:
+            # install the external APIs
+            packages = []
+            for _, api_spec in external_apis.items():
+                if api_spec.pip_packages:
+                    packages.extend(api_spec.pip_packages)
+                    cprint(
+                        f"Installing {api_spec.name} with pip packages {api_spec.pip_packages}",
+                        color="yellow",
+                        file=sys.stderr,
+                    )
+            return_code = run_command(["uv", "pip", "install", *packages])
+            if return_code != 0:
+                packages_str = ", ".join(packages)
+                raise RuntimeError(
+                    f"Failed to install external APIs packages: {packages_str} (return code: {return_code})"
+                )
+
     return_code = build_image(
         build_config,
         build_file_path,

llama_stack/distribution/build.py

@@ -14,6 +14,7 @@ from termcolor import cprint
 
 from llama_stack.distribution.datatypes import BuildConfig
 from llama_stack.distribution.distribution import get_provider_registry
+from llama_stack.distribution.external import load_external_apis
 from llama_stack.distribution.utils.exec import run_command
 from llama_stack.distribution.utils.image_types import LlamaStackImageType
 from llama_stack.providers.datatypes import Api
@@ -105,6 +106,11 @@ def build_image(
 
     normal_deps, special_deps = get_provider_dependencies(build_config)
     normal_deps += SERVER_DEPENDENCIES
+    if build_config.external_apis_dir:
+        external_apis = load_external_apis(build_config)
+        if external_apis:
+            for _, api_spec in external_apis.items():
+                normal_deps.extend(api_spec.pip_packages)
 
     if build_config.image_type == LlamaStackImageType.CONTAINER.value:
         script = str(importlib.resources.files("llama_stack") / "distribution/build_container.sh")

llama_stack/distribution/datatypes.py

@@ -289,6 +289,11 @@ a default SQLite store will be used.""",
         description="Path to directory containing external provider implementations. The providers code and dependencies must be installed on the system.",
     )
 
+    external_apis_dir: Path | None = Field(
+        default=None,
+        description="Path to directory containing external API implementations. The APIs code and dependencies must be installed on the system.",
+    )
+
     @field_validator("external_providers_dir")
     @classmethod
     def validate_external_providers_dir(cls, v):
@@ -320,6 +325,10 @@ class BuildConfig(BaseModel):
         default_factory=list,
         description="Additional pip packages to install in the distribution. These packages will be installed in the distribution environment.",
     )
+    external_apis_dir: Path | None = Field(
+        default=None,
+        description="Path to directory containing external API implementations. The APIs code and dependencies must be installed on the system.",
+    )
 
     @field_validator("external_providers_dir")
     @classmethod

llama_stack/distribution/distribution.py

@@ -12,6 +12,7 @@ from typing import Any
 import yaml
 from pydantic import BaseModel
 
+from llama_stack.distribution.external import load_external_apis
 from llama_stack.log import get_logger
 from llama_stack.providers.datatypes import (
     AdapterSpec,
@@ -133,16 +134,34 @@ def get_provider_registry(
         ValueError: If any provider spec is invalid
     """
 
-    ret: dict[Api, dict[str, ProviderSpec]] = {}
+    registry: dict[Api, dict[str, ProviderSpec]] = {}
     for api in providable_apis():
         name = api.name.lower()
         logger.debug(f"Importing module {name}")
         try:
             module = importlib.import_module(f"llama_stack.providers.registry.{name}")
-            ret[api] = {a.provider_type: a for a in module.available_providers()}
+            registry[api] = {a.provider_type: a for a in module.available_providers()}
         except ImportError as e:
             logger.warning(f"Failed to import module {name}: {e}")
 
+    # Refresh providable APIs with external APIs if any
+    external_apis = load_external_apis(config)
+    for api, api_spec in external_apis.items():
+        name = api_spec.name.lower()
+        logger.info(f"Importing external API {name} module {api_spec.module}")
+        try:
+            module = importlib.import_module(api_spec.module)
+            registry[api] = {a.provider_type: a for a in module.available_providers()}
+        except (ImportError, AttributeError) as e:
+            # Populate the registry with an empty dict to avoid breaking the provider registry
+            # This assume that the in-tree provider(s) are not available for this API which means
+            # that users will need to use external providers for this API.
+            registry[api] = {}
+            logger.error(
+                f"Failed to import external API {name}: {e}. Could not populate the in-tree provider(s) registry for {api.name}. \n"
+                "Install the API package to load any in-tree providers for this API."
+            )
+
     # Check if config has the external_providers_dir attribute
     if config and hasattr(config, "external_providers_dir") and config.external_providers_dir:
         external_providers_dir = os.path.abspath(os.path.expanduser(config.external_providers_dir))
@@ -175,11 +194,9 @@ def get_provider_registry(
                         else:
                             spec = _load_inline_provider_spec(spec_data, api, provider_name)
                             provider_type_key = f"inline::{provider_name}"
-
-                        logger.info(f"Loaded {provider_type} provider spec for {provider_type_key} from {spec_path}")
-                        if provider_type_key in ret[api]:
+                        if provider_type_key in registry[api]:
                             logger.warning(f"Overriding already registered provider {provider_type_key} for {api.name}")
-                        ret[api][provider_type_key] = spec
+                        registry[api][provider_type_key] = spec
                         logger.info(f"Successfully loaded external provider {provider_type_key}")
                     except yaml.YAMLError as yaml_err:
                         logger.error(f"Failed to parse YAML file {spec_path}: {yaml_err}")
@@ -187,4 +204,4 @@ def get_provider_registry(
                     except Exception as e:
                         logger.error(f"Failed to load provider spec from {spec_path}: {e}")
                         raise e
-    return ret
+    return registry

llama_stack/distribution/external.py

@@ -0,0 +1,59 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+
+import yaml
+
+from llama_stack.apis.datatypes import Api, ExternalApiSpec
+from llama_stack.log import get_logger
+
+logger = get_logger(name=__name__, category="core")
+
+
+def load_external_apis(config=None) -> dict[Api, ExternalApiSpec]:
+    """Load external API specifications from the configured directory.
+
+    Args:
+        config: StackRunConfig containing the external APIs directory path
+
+    Returns:
+        A dictionary mapping API names to their specifications
+    """
+    if not config:
+        return {}
+
+    if not hasattr(config, "external_apis_dir"):
+        return {}
+
+    if not config.external_apis_dir:
+        return {}
+
+    external_apis_dir = config.external_apis_dir.expanduser().resolve()
+    if not external_apis_dir.is_dir():
+        logger.error(f"External APIs directory is not a directory: {external_apis_dir}")
+        return {}
+
+    logger.info(f"Loading external APIs from {external_apis_dir}")
+    external_apis: dict[Api, ExternalApiSpec] = {}
+
+    # Look for YAML files in the external APIs directory
+    for yaml_path in external_apis_dir.glob("*.yaml"):
+        try:
+            with open(yaml_path) as f:
+                spec_data = yaml.safe_load(f)
+
+            spec = ExternalApiSpec(**spec_data)
+            api = Api.add(spec.name)
+            logger.info(f"Loaded external API spec for {spec.name} from {yaml_path}")
+            external_apis[api] = spec
+        except yaml.YAMLError as yaml_err:
+            logger.error(f"Failed to parse YAML file {yaml_path}: {yaml_err}")
+            raise yaml_err
+        except Exception as e:
+            logger.error(f"Failed to load external API spec from {yaml_path}: {e}")
+            raise e
+
+    return external_apis

llama_stack/distribution/inspect.py

@@ -16,6 +16,7 @@ from llama_stack.apis.inspect import (
     VersionInfo,
 )
 from llama_stack.distribution.datatypes import StackRunConfig
+from llama_stack.distribution.external import load_external_apis
 from llama_stack.distribution.server.routes import get_all_api_routes
 from llama_stack.providers.datatypes import HealthStatus
 
@@ -42,7 +43,8 @@ class DistributionInspectImpl(Inspect):
         run_config: StackRunConfig = self.config.run_config
 
         ret = []
-        all_endpoints = get_all_api_routes()
+        external_apis = load_external_apis(run_config)
+        all_endpoints = get_all_api_routes(external_apis)
         for api, endpoints in all_endpoints.items():
             # Always include provider and inspect APIs, filter others based on run config
             if api.value in ["providers", "inspect"]:

llama_stack/distribution/resolver.py

@@ -11,6 +11,7 @@ from llama_stack.apis.agents import Agents
 from llama_stack.apis.benchmarks import Benchmarks
 from llama_stack.apis.datasetio import DatasetIO
 from llama_stack.apis.datasets import Datasets
+from llama_stack.apis.datatypes import ExternalApiSpec
 from llama_stack.apis.eval import Eval
 from llama_stack.apis.files import Files
 from llama_stack.apis.inference import Inference, InferenceProvider
@@ -35,6 +36,7 @@ from llama_stack.distribution.datatypes import (
     StackRunConfig,
 )
 from llama_stack.distribution.distribution import builtin_automatically_routed_apis
+from llama_stack.distribution.external import load_external_apis
 from llama_stack.distribution.store import DistributionRegistry
 from llama_stack.distribution.utils.dynamic import instantiate_class_type
 from llama_stack.log import get_logger
@@ -59,8 +61,16 @@ class InvalidProviderError(Exception):
     pass
 
 
-def api_protocol_map() -> dict[Api, Any]:
-    return {
+def api_protocol_map(external_apis: dict[Api, ExternalApiSpec] | None = None) -> dict[Api, Any]:
+    """Get a mapping of API types to their protocol classes.
+
+    Args:
+        external_apis: Optional dictionary of external API specifications
+
+    Returns:
+        Dictionary mapping API types to their protocol classes
+    """
+    protocols = {
         Api.providers: ProvidersAPI,
         Api.agents: Agents,
         Api.inference: Inference,
@@ -83,10 +93,23 @@ def api_protocol_map() -> dict[Api, Any]:
         Api.files: Files,
     }
 
+    if external_apis:
+        for api, api_spec in external_apis.items():
+            try:
+                module = importlib.import_module(api_spec.module)
+                api_class = getattr(module, api_spec.protocol)
 
-def api_protocol_map_for_compliance_check() -> dict[Api, Any]:
+                protocols[api] = api_class
+            except (ImportError, AttributeError) as e:
+                logger.warning(f"Failed to load external API {api_spec.name}: {e}")
+
+    return protocols
+
+
+def api_protocol_map_for_compliance_check(config: Any) -> dict[Api, Any]:
+    external_apis = load_external_apis(config)
     return {
-        **api_protocol_map(),
+        **api_protocol_map(external_apis),
         Api.inference: InferenceProvider,
     }
 
@@ -250,7 +273,7 @@ async def instantiate_providers(
     dist_registry: DistributionRegistry,
     run_config: StackRunConfig,
     policy: list[AccessRule],
-) -> dict:
+) -> dict[Api, Any]:
     """Instantiates providers asynchronously while managing dependencies."""
     impls: dict[Api, Any] = {}
     inner_impls_by_provider_id: dict[str, dict[str, Any]] = {f"inner-{x.value}": {} for x in router_apis}
@@ -356,7 +379,7 @@ async def instantiate_provider(
     impl.__provider_spec__ = provider_spec
     impl.__provider_config__ = config
 
-    protocols = api_protocol_map_for_compliance_check()
+    protocols = api_protocol_map_for_compliance_check(run_config)
     additional_protocols = additional_protocols_map()
     # TODO: check compliance for special tool groups
     # the impl should be for Api.tool_runtime, the name should be the special tool group, the protocol should be the special tool group protocol

llama_stack/distribution/server/routes.py

@@ -12,10 +12,9 @@ from typing import Any
 from aiohttp import hdrs
 from starlette.routing import Route
 
+from llama_stack.apis.datatypes import Api, ExternalApiSpec
 from llama_stack.apis.tools import RAGToolRuntime, SpecialToolGroup
 from llama_stack.apis.version import LLAMA_STACK_API_VERSION
-from llama_stack.distribution.resolver import api_protocol_map
-from llama_stack.providers.datatypes import Api
 
 EndpointFunc = Callable[..., Any]
 PathParams = dict[str, str]
@@ -31,10 +30,13 @@ def toolgroup_protocol_map():
     }
 
 
-def get_all_api_routes() -> dict[Api, list[Route]]:
+def get_all_api_routes(external_apis: dict[Api, ExternalApiSpec] | None = None) -> dict[Api, list[Route]]:
     apis = {}
 
-    protocols = api_protocol_map()
+    # Lazy import to avoid circular dependency
+    from llama_stack.distribution.resolver import api_protocol_map
+
+    protocols = api_protocol_map(external_apis)
     toolgroup_protocols = toolgroup_protocol_map()
     for api, protocol in protocols.items():
         routes = []
@@ -73,8 +75,8 @@ def get_all_api_routes() -> dict[Api, list[Route]]:
     return apis
 
 
-def initialize_route_impls(impls: dict[Api, Any]) -> RouteImpls:
-    routes = get_all_api_routes()
+def initialize_route_impls(impls, external_apis: dict[Api, ExternalApiSpec] | None = None) -> RouteImpls:
+    routes = get_all_api_routes(external_apis)
     route_impls: RouteImpls = {}
 
     def _convert_path_to_regex(path: str) -> str:

llama_stack/distribution/server/server.py

@@ -33,6 +33,7 @@ from pydantic import BaseModel, ValidationError
 from llama_stack.apis.common.responses import PaginatedResponse
 from llama_stack.distribution.datatypes import AuthenticationRequiredError, LoggingConfig, StackRunConfig
 from llama_stack.distribution.distribution import builtin_automatically_routed_apis
+from llama_stack.distribution.external import ExternalApiSpec, load_external_apis
 from llama_stack.distribution.request_headers import PROVIDER_DATA_VAR, User, request_provider_data_context
 from llama_stack.distribution.resolver import InvalidProviderError
 from llama_stack.distribution.server.routes import (
@@ -270,9 +271,10 @@ def create_dynamic_typed_route(func: Any, method: str, route: str) -> Callable:
 
 
 class TracingMiddleware:
-    def __init__(self, app, impls):
+    def __init__(self, app, impls, external_apis: dict[str, ExternalApiSpec]):
         self.app = app
         self.impls = impls
+        self.external_apis = external_apis
         # FastAPI built-in paths that should bypass custom routing
         self.fastapi_paths = ("/docs", "/redoc", "/openapi.json", "/favicon.ico", "/static")
 
@@ -289,7 +291,7 @@ class TracingMiddleware:
             return await self.app(scope, receive, send)
 
         if not hasattr(self, "route_impls"):
-            self.route_impls = initialize_route_impls(self.impls)
+            self.route_impls = initialize_route_impls(self.impls, self.external_apis)
 
         try:
             _, _, trace_path = find_matching_route(scope.get("method", hdrs.METH_GET), path, self.route_impls)
@@ -493,7 +495,9 @@ def main(args: argparse.Namespace | None = None):
     else:
         setup_logger(TelemetryAdapter(TelemetryConfig(), {}))
 
-    all_routes = get_all_api_routes()
+    # Load external APIs if configured
+    external_apis = load_external_apis(config)
+    all_routes = get_all_api_routes(external_apis)
 
     if config.apis:
         apis_to_serve = set(config.apis)
@@ -512,7 +516,10 @@ def main(args: argparse.Namespace | None = None):
         api = Api(api_str)
 
         routes = all_routes[api]
-        impl = impls[api]
+        try:
+            impl = impls[api]
+        except KeyError as e:
+            raise ValueError(f"Could not find provider implementation for {api} API") from e
 
         for route in routes:
             if not hasattr(impl, route.name):
@@ -543,7 +550,7 @@ def main(args: argparse.Namespace | None = None):
     app.exception_handler(Exception)(global_exception_handler)
 
     app.__llama_stack_impls__ = impls
-    app.add_middleware(TracingMiddleware, impls=impls)
+    app.add_middleware(TracingMiddleware, impls=impls, external_apis=external_apis)
 
     import uvicorn
 

tests/external-provider/llama-stack-provider-ollama/README.md

@@ -1,3 +0,0 @@
-# Ollama external provider for Llama Stack
-
-Template code to create a new external provider for Llama Stack.

tests/external-provider/llama-stack-provider-ollama/custom_ollama.yaml

@@ -1,7 +0,0 @@
-adapter:
-  adapter_type: custom_ollama
-  pip_packages: ["ollama", "aiohttp", "tests/external-provider/llama-stack-provider-ollama"]
-  config_class: llama_stack_provider_ollama.config.OllamaImplConfig
-  module: llama_stack_provider_ollama
-api_dependencies: []
-optional_api_dependencies: []

tests/external-provider/llama-stack-provider-ollama/pyproject.toml

@@ -1,43 +0,0 @@
-[project]
-dependencies = [
-    "llama-stack",
-    "pydantic",
-    "ollama",
-    "aiohttp",
-    "aiosqlite",
-    "autoevals",
-    "chardet",
-    "chromadb-client",
-    "datasets",
-    "faiss-cpu",
-    "fastapi",
-    "fire",
-    "httpx",
-    "matplotlib",
-    "mcp",
-    "nltk",
-    "numpy",
-    "openai",
-    "opentelemetry-exporter-otlp-proto-http",
-    "opentelemetry-sdk",
-    "pandas",
-    "pillow",
-    "psycopg2-binary",
-    "pymongo",
-    "pypdf",
-    "redis",
-    "requests",
-    "scikit-learn",
-    "scipy",
-    "sentencepiece",
-    "tqdm",
-    "transformers",
-    "tree_sitter",
-    "uvicorn",
-]
-
-name = "llama-stack-provider-ollama"
-version = "0.1.0"
-description = "External provider for Ollama using the Llama Stack API"
-readme = "README.md"
-requires-python = ">=3.12"

tests/external-provider/llama-stack-provider-ollama/run.yaml

@@ -1,94 +0,0 @@
-version: '2'
-image_name: ollama
-apis:
-- inference
-- telemetry
-- tool_runtime
-- datasetio
-- vector_io
-providers:
-  inference:
-  - provider_id: custom_ollama
-    provider_type: remote::custom_ollama
-    config:
-      url: ${env.OLLAMA_URL:http://localhost:11434}
-  vector_io:
-  - provider_id: faiss
-    provider_type: inline::faiss
-    config:
-      kvstore:
-        type: sqlite
-        namespace: null
-        db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/faiss_store.db
-  telemetry:
-  - provider_id: meta-reference
-    provider_type: inline::meta-reference
-    config:
-      service_name: "${env.OTEL_SERVICE_NAME:\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:console,sqlite}
-      sqlite_db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/trace_store.db
-  datasetio:
-  - provider_id: huggingface
-    provider_type: remote::huggingface
-    config:
-      kvstore:
-        type: sqlite
-        namespace: null
-        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
-  tool_runtime:
-  - provider_id: brave-search
-    provider_type: remote::brave-search
-    config:
-      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:}
-      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:}
-metadata_store:
-  type: sqlite
-  db_path: ${env.SQLITE_STORE_DIR:~/.llama/distributions/ollama}/registry.db
-models:
-- metadata: {}
-  model_id: ${env.INFERENCE_MODEL}
-  provider_id: custom_ollama
-  model_type: llm
-- metadata:
-    embedding_dimension: 384
-  model_id: all-MiniLM-L6-v2
-  provider_id: custom_ollama
-  provider_model_id: all-minilm:latest
-  model_type: embedding
-shields: []
-vector_dbs: []
-datasets: []
-scoring_fns: []
-benchmarks: []
-tool_groups:
-- toolgroup_id: builtin::websearch
-  provider_id: tavily-search
-- toolgroup_id: builtin::rag
-  provider_id: rag-runtime
-- toolgroup_id: builtin::wolfram_alpha
-  provider_id: wolfram-alpha
-server:
-  port: 8321
-external_providers_dir: ~/.llama/providers.d

tests/external/build.yaml

@@ -2,8 +2,9 @@ version: '2'
 distribution_spec:
   description: Custom distro for CI tests
   providers:
-    inference:
-    - remote::custom_ollama
-image_type: container
+    weather:
+    - remote::kaze
+image_type: venv
 image_name: ci-test
 external_providers_dir: ~/.llama/providers.d
+external_apis_dir: ~/.llama/apis.d

tests/external/kaze.yaml

@@ -0,0 +1,6 @@
+adapter:
+  adapter_type: kaze
+  pip_packages: ["tests/external/llama-stack-provider-kaze"]
+  config_class: llama_stack_provider_kaze.config.KazeProviderConfig
+  module: llama_stack_provider_kaze
+optional_api_dependencies: []

tests/external/llama-stack-api-weather/pyproject.toml

@@ -0,0 +1,15 @@
+[project]
+name = "llama-stack-api-weather"
+version = "0.1.0"
+description = "Weather API for Llama Stack"
+readme = "README.md"
+requires-python = ">=3.10"
+dependencies = ["llama-stack", "pydantic"]
+
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+include = ["llama_stack_api_weather", "llama_stack_api_weather.*"]

tests/external/llama-stack-api-weather/src/llama_stack_api_weather/__init__.py

@@ -0,0 +1,11 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+"""Weather API for Llama Stack."""
+
+from .weather import WeatherProvider, available_providers
+
+__all__ = ["WeatherProvider", "available_providers"]

tests/external/llama-stack-api-weather/src/llama_stack_api_weather/weather.py

@@ -0,0 +1,39 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import Protocol
+
+from llama_stack.providers.datatypes import AdapterSpec, Api, ProviderSpec, RemoteProviderSpec
+from llama_stack.schema_utils import webmethod
+
+
+def available_providers() -> list[ProviderSpec]:
+    return [
+        RemoteProviderSpec(
+            api=Api.weather,
+            provider_type="remote::kaze",
+            config_class="llama_stack_provider_kaze.KazeProviderConfig",
+            adapter=AdapterSpec(
+                adapter_type="kaze",
+                module="llama_stack_provider_kaze",
+                pip_packages=["llama_stack_provider_kaze"],
+                config_class="llama_stack_provider_kaze.KazeProviderConfig",
+            ),
+        ),
+    ]
+
+
+class WeatherProvider(Protocol):
+    """
+    A protocol for the Weather API.
+    """
+
+    @webmethod(route="/weather/locations", method="GET")
+    async def get_available_locations() -> dict[str, list[str]]:
+        """
+        Get the available locations.
+        """
+        ...

tests/external/llama-stack-provider-kaze/pyproject.toml

@@ -0,0 +1,15 @@
+[project]
+name = "llama-stack-provider-kaze"
+version = "0.1.0"
+description = "Kaze weather provider for Llama Stack"
+readme = "README.md"
+requires-python = ">=3.10"
+dependencies = ["llama-stack", "pydantic", "aiohttp"]
+
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+include = ["llama_stack_provider_kaze", "llama_stack_provider_kaze.*"]

tests/external/llama-stack-provider-kaze/src/llama_stack_provider_kaze/__init__.py

@@ -0,0 +1,20 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+"""Kaze weather provider for Llama Stack."""
+
+from .config import KazeProviderConfig
+from .kaze import WeatherKazeAdapter
+
+__all__ = ["KazeProviderConfig", "WeatherKazeAdapter"]
+
+
+async def get_adapter_impl(config: KazeProviderConfig, _deps):
+    from .kaze import WeatherKazeAdapter
+
+    impl = WeatherKazeAdapter(config)
+    await impl.initialize()
+    return impl

tests/external/llama-stack-provider-kaze/src/llama_stack_provider_kaze/config.py

@@ -0,0 +1,11 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from pydantic import BaseModel
+
+
+class KazeProviderConfig(BaseModel):
+    """Configuration for the Kaze weather provider."""

tests/external/llama-stack-provider-kaze/src/llama_stack_provider_kaze/kaze.py

@@ -0,0 +1,26 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from llama_stack_api_weather.weather import WeatherProvider
+
+from .config import KazeProviderConfig
+
+
+class WeatherKazeAdapter(WeatherProvider):
+    """Kaze weather provider implementation."""
+
+    def __init__(
+        self,
+        config: KazeProviderConfig,
+    ) -> None:
+        self.config = config
+
+    async def initialize(self) -> None:
+        pass
+
+    async def get_available_locations(self) -> dict[str, list[str]]:
+        """Get available weather locations."""
+        return {"locations": ["Paris", "Tokyo"]}

tests/external/run-byoa.yaml

@@ -0,0 +1,13 @@
+version: "2"
+image_name: "llama-stack-api-weather"
+apis:
+  - weather
+providers:
+  weather:
+  - provider_id: kaze
+    provider_type: remote::kaze
+    config: {}
+external_apis_dir: ~/.llama/apis.d
+external_providers_dir: ~/.llama/providers.d
+server:
+  port: 8321

tests/external/weather.yaml

@@ -0,0 +1,4 @@
+module: llama_stack_api_weather
+name: weather
+pip_packages: ["tests/external/llama-stack-api-weather"]
+protocol: WeatherProvider