feat: Adding OpenAI Compatible Prompts API

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>

llama_stack/core/prompts/__init__.py

@@ -0,0 +1,5 @@
+# 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.

llama_stack/core/prompts/prompts.py

@@ -0,0 +1,182 @@
+# 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 json
+from typing import Any
+
+from pydantic import BaseModel
+
+from llama_stack.apis.prompts import ListPromptsResponse, Prompt, Prompts
+from llama_stack.providers.utils.kvstore import KVStore, kvstore_impl
+from llama_stack.providers.utils.kvstore.config import KVStoreConfig
+
+
+class PromptServiceConfig(BaseModel):
+    """Configuration for the built-in prompt service.
+
+    :param kvstore: Configuration for the key-value store backend
+    """
+
+    kvstore: KVStoreConfig
+
+
+async def get_provider_impl(config: PromptServiceConfig, deps: dict[Any, Any]):
+    """Get the prompt service implementation."""
+    impl = PromptServiceImpl(config, deps)
+    await impl.initialize()
+    return impl
+
+
+class PromptServiceImpl(Prompts):
+    """Built-in prompt service implementation using KVStore."""
+
+    def __init__(self, config: PromptServiceConfig, deps: dict[Any, Any]):
+        self.config = config
+        self.deps = deps
+        self.kvstore: KVStore
+
+    async def initialize(self) -> None:
+        self.kvstore = await kvstore_impl(self.config.kvstore)
+
+    def _get_prompt_key(self, prompt_id: str, version: str | None = None) -> str:
+        if version:
+            return f"prompts:v1:{prompt_id}:{version}"
+        return f"prompts:v1:{prompt_id}:default"
+
+    def _get_version_key(self, prompt_id: str, version: str) -> str:
+        """Get the KVStore key for a specific prompt version."""
+        return f"prompts:v1:{prompt_id}:{version}"
+
+    def _get_list_key_prefix(self) -> str:
+        """Get the key prefix for listing prompts."""
+        return "prompts:v1:"
+
+    def _serialize_prompt(self, prompt: Prompt) -> str:
+        """Serialize a prompt to JSON string for storage."""
+        return json.dumps(
+            {
+                "prompt_id": prompt.prompt_id,
+                "prompt": prompt.prompt,
+                "version": prompt.version,
+                "variables": prompt.variables or {},
+            }
+        )
+
+    def _deserialize_prompt(self, data: str) -> Prompt:
+        """Deserialize a prompt from JSON string."""
+        obj = json.loads(data)
+        return Prompt(
+            prompt_id=obj["prompt_id"], prompt=obj["prompt"], version=obj["version"], variables=obj.get("variables", {})
+        )
+
+    async def list_prompts(self) -> ListPromptsResponse:
+        """List all prompts (default versions only)."""
+        prefix = self._get_list_key_prefix()
+        keys = await self.kvstore.keys_in_range(prefix, prefix + "\xff")
+
+        prompts = []
+        for key in keys:
+            if key.endswith(":default"):
+                try:
+                    default_version = await self.kvstore.get(key)
+                    if default_version:
+                        prompt_id = key.replace(prefix, "").replace(":default", "")
+                        version_key = self._get_version_key(prompt_id, default_version)
+                        data = await self.kvstore.get(version_key)
+                        if data:
+                            prompt = self._deserialize_prompt(data)
+                            prompts.append(prompt)
+                except (json.JSONDecodeError, KeyError):
+                    continue
+
+        prompts.sort(key=lambda p: p.prompt_id or "", reverse=True)
+        return ListPromptsResponse(data=prompts)
+
+    async def get_prompt(self, prompt_id: str, version: str | None = None) -> Prompt:
+        """Get a prompt by its identifier and optional version."""
+        if version:
+            key = self._get_version_key(prompt_id, version)
+            data = await self.kvstore.get(key)
+            if data is None:
+                raise ValueError(f"Prompt {prompt_id} version {version} not found")
+        else:
+            default_key = self._get_prompt_key(prompt_id)
+            default_version = await self.kvstore.get(default_key)
+            if default_version is None:
+                raise ValueError(f"Prompt with ID '{prompt_id}' not found")
+
+            key = self._get_version_key(prompt_id, default_version)
+            data = await self.kvstore.get(key)
+            if data is None:
+                raise ValueError(f"Prompt with ID '{prompt_id}' not found")
+
+        return self._deserialize_prompt(data)
+
+    async def create_prompt(
+        self,
+        prompt: str,
+        variables: dict[str, str] | None = None,
+    ) -> Prompt:
+        """Create a new prompt."""
+        if variables is None:
+            variables = {}
+
+        prompt_obj = Prompt(prompt_id=Prompt.generate_prompt_id(), prompt=prompt, version="1", variables=variables)
+
+        version_key = self._get_version_key(prompt_obj.prompt_id, "1")
+        data = self._serialize_prompt(prompt_obj)
+        await self.kvstore.set(version_key, data)
+
+        default_key = self._get_prompt_key(prompt_obj.prompt_id)
+        await self.kvstore.set(default_key, "1")
+
+        return prompt_obj
+
+    async def update_prompt(
+        self,
+        prompt_id: str,
+        prompt: str,
+        variables: dict[str, str] | None = None,
+    ) -> Prompt:
+        """Update an existing prompt (increments version)."""
+        if variables is None:
+            variables = {}
+
+        current_prompt = await self.get_prompt(prompt_id)
+        new_version = str(int(current_prompt.version) + 1)
+
+        updated_prompt = Prompt(prompt_id=prompt_id, prompt=prompt, version=new_version, variables=variables)
+
+        version_key = self._get_version_key(prompt_id, new_version)
+        data = self._serialize_prompt(updated_prompt)
+        await self.kvstore.set(version_key, data)
+
+        default_key = self._get_prompt_key(prompt_id)
+        await self.kvstore.set(default_key, new_version)
+
+        return updated_prompt
+
+    async def delete_prompt(self, prompt_id: str) -> None:
+        """Delete a prompt and all its versions."""
+        await self.get_prompt(prompt_id)
+
+        prefix = f"prompts:v1:{prompt_id}:"
+        keys = await self.kvstore.keys_in_range(prefix, prefix + "\xff")
+
+        for key in keys:
+            await self.kvstore.delete(key)
+
+    async def set_default_version(self, prompt_id: str, version: str) -> Prompt:
+        """Set which version of a prompt should be the default (latest)."""
+        version_key = self._get_version_key(prompt_id, version)
+        data = await self.kvstore.get(version_key)
+        if data is None:
+            raise ValueError(f"Prompt {prompt_id} version {version} not found")
+
+        default_key = self._get_prompt_key(prompt_id)
+        await self.kvstore.set(default_key, version)
+
+        return self._deserialize_prompt(data)

llama_stack/core/resolver.py

@@ -19,6 +19,7 @@ from llama_stack.apis.inference import Inference, InferenceProvider
 from llama_stack.apis.inspect import Inspect
 from llama_stack.apis.models import Models
 from llama_stack.apis.post_training import PostTraining
+from llama_stack.apis.prompts import Prompts
 from llama_stack.apis.providers import Providers as ProvidersAPI
 from llama_stack.apis.safety import Safety
 from llama_stack.apis.scoring import Scoring
@@ -93,6 +94,7 @@ def api_protocol_map(external_apis: dict[Api, ExternalApiSpec] | None = None) ->
         Api.tool_groups: ToolGroups,
         Api.tool_runtime: ToolRuntime,
         Api.files: Files,
+        Api.prompts: Prompts,
     }
 
     if external_apis:
@@ -284,7 +286,15 @@ async def instantiate_providers(
         if provider.provider_id is None:
             continue
 
-        deps = {a: impls[a] for a in provider.spec.api_dependencies}
+        try:
+            deps = {a: impls[a] for a in provider.spec.api_dependencies}
+        except KeyError as e:
+            missing_api = e.args[0]
+            raise RuntimeError(
+                f"Failed to resolve '{provider.spec.api.value}' provider '{provider.provider_id}' of type '{provider.spec.provider_type}': "
+                f"required dependency '{missing_api.value}' is not available. "
+                f"Please add a '{missing_api.value}' provider to your configuration or check if the provider is properly configured."
+            ) from e
         for a in provider.spec.optional_api_dependencies:
             if a in impls:
                 deps[a] = impls[a]

llama_stack/core/routers/inference.py

@@ -755,7 +755,7 @@ class InferenceRouter(Inference):
                             choices_data[idx] = {
                                 "content_parts": [],
                                 "tool_calls_builder": {},
-                                "finish_reason": None,
+                                "finish_reason": "stop",
                                 "logprobs_content_parts": [],
                             }
                         current_choice_data = choices_data[idx]

llama_stack/core/server/server.py

@@ -132,9 +132,9 @@ def translate_exception(exc: Exception) -> HTTPException | RequestValidationErro
             },
         )
     elif isinstance(exc, ConflictError):
-        return HTTPException(status_code=409, detail=str(exc))
+        return HTTPException(status_code=httpx.codes.CONFLICT, detail=str(exc))
     elif isinstance(exc, ResourceNotFoundError):
-        return HTTPException(status_code=404, detail=str(exc))
+        return HTTPException(status_code=httpx.codes.NOT_FOUND, detail=str(exc))
     elif isinstance(exc, ValueError):
         return HTTPException(status_code=httpx.codes.BAD_REQUEST, detail=f"Invalid value: {str(exc)}")
     elif isinstance(exc, BadRequestError):
@@ -513,6 +513,7 @@ def main(args: argparse.Namespace | None = None):
 
     apis_to_serve.add("inspect")
     apis_to_serve.add("providers")
+    apis_to_serve.add("prompts")
     for api_str in apis_to_serve:
         api = Api(api_str)
 

llama_stack/core/stack.py

@@ -24,6 +24,7 @@ from llama_stack.apis.inference import Inference
 from llama_stack.apis.inspect import Inspect
 from llama_stack.apis.models import Models
 from llama_stack.apis.post_training import PostTraining
+from llama_stack.apis.prompts import Prompts
 from llama_stack.apis.providers import Providers
 from llama_stack.apis.safety import Safety
 from llama_stack.apis.scoring import Scoring
@@ -37,6 +38,7 @@ from llama_stack.apis.vector_io import VectorIO
 from llama_stack.core.datatypes import Provider, StackRunConfig
 from llama_stack.core.distribution import get_provider_registry
 from llama_stack.core.inspect import DistributionInspectConfig, DistributionInspectImpl
+from llama_stack.core.prompts.prompts import PromptServiceConfig, PromptServiceImpl
 from llama_stack.core.providers import ProviderImpl, ProviderImplConfig
 from llama_stack.core.resolver import ProviderRegistry, resolve_impls
 from llama_stack.core.routing_tables.common import CommonRoutingTableImpl
@@ -44,6 +46,7 @@ from llama_stack.core.store.registry import create_dist_registry
 from llama_stack.core.utils.dynamic import instantiate_class_type
 from llama_stack.log import get_logger
 from llama_stack.providers.datatypes import Api
+from llama_stack.providers.utils.kvstore.config import SqliteKVStoreConfig
 
 logger = get_logger(name=__name__, category="core")
 
@@ -72,6 +75,7 @@ class LlamaStack(
     ToolRuntime,
     RAGToolRuntime,
     Files,
+    Prompts,
 ):
     pass
 
@@ -105,12 +109,12 @@ async def register_resources(run_config: StackRunConfig, impls: dict[Api, Any]):
 
         method = getattr(impls[api], register_method)
         for obj in objects:
-            logger.debug(f"registering {rsrc.capitalize()} {obj} for provider {obj.provider_id}")
-
-            # Do not register models on disabled providers
-            if hasattr(obj, "provider_id") and (not obj.provider_id or obj.provider_id == "__disabled__"):
-                logger.debug(f"Skipping {rsrc.capitalize()} registration for disabled provider.")
-                continue
+            if hasattr(obj, "provider_id"):
+                # Do not register models on disabled providers
+                if not obj.provider_id or obj.provider_id == "__disabled__":
+                    logger.debug(f"Skipping {rsrc.capitalize()} registration for disabled provider.")
+                    continue
+                logger.debug(f"registering {rsrc.capitalize()} {obj} for provider {obj.provider_id}")
 
             # we want to maintain the type information in arguments to method.
             # instead of method(**obj.model_dump()), which may convert a typed attr to a dict,
@@ -305,6 +309,12 @@ def add_internal_implementations(impls: dict[Api, Any], run_config: StackRunConf
     )
     impls[Api.providers] = providers_impl
 
+    prompts_impl = PromptServiceImpl(
+        PromptServiceConfig(kvstore=SqliteKVStoreConfig(db_path=os.path.expanduser("~/.llama-stack/prompts.db"))),
+        deps=impls,
+    )
+    impls[Api.prompts] = prompts_impl
+
 
 # Produces a stack of providers for the given run config. Not all APIs may be
 # asked for in the run config.
@@ -329,6 +339,9 @@ async def construct_stack(
     # Add internal implementations after all other providers are resolved
     add_internal_implementations(impls, run_config)
 
+    if Api.prompts in impls:
+        await impls[Api.prompts].initialize()
+
     await register_resources(run_config, impls)
 
     await refresh_registry_once(impls)