feat: Adding OpenAI Compatible Prompts API

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

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)