llama-stack-mirror/llama_stack/apis/tools/tools.py
Ashwin Bharambe 51945f1e57
feat: accept MCP authorization headers for MCP toolgroups (#2230)
The most interesting MCP servers are those with an authorization wall in
front of them. This PR uses the existing `provider_data` mechanism of
passing provider API keys for passing MCP access tokens (in fact,
arbitrary headers in the style of the OpenAI Responses API) from the
client through to the MCP server.

```
class MCPProviderDataValidator(BaseModel):
    # mcp_endpoint => list of headers to send
    mcp_headers: dict[str, list[str]] | None = None
```

Note how we must stuff the headers for all MCP endpoints into a single
"MCPProviderDataValidator". Unlike existing providers (e.g., Together
and Fireworks for inference) where we could name the provider api keys
clearly (`together_api_key`, `fireworks_api_key`), we cannot name these
keys for MCP. We have a single generic MCP provider which can serve
multiple "toolgroups". So we use a dict to combine all the headers for
all MCP endpoints you may want to use in an agentic call.


## Test Plan

See the added integration test for usage.
2025-05-23 08:52:18 -07:00

200 lines
5.5 KiB
Python

# 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 enum import Enum
from typing import Any, Literal
from pydantic import BaseModel, Field
from typing_extensions import Protocol, runtime_checkable
from llama_stack.apis.common.content_types import URL, InterleavedContent
from llama_stack.apis.resource import Resource, ResourceType
from llama_stack.providers.utils.telemetry.trace_protocol import trace_protocol
from llama_stack.schema_utils import json_schema_type, webmethod
from .rag_tool import RAGToolRuntime
@json_schema_type
class ToolParameter(BaseModel):
name: str
parameter_type: str
description: str
required: bool = Field(default=True)
default: Any | None = None
@json_schema_type
class ToolHost(Enum):
distribution = "distribution"
client = "client"
model_context_protocol = "model_context_protocol"
@json_schema_type
class Tool(Resource):
type: Literal[ResourceType.tool] = ResourceType.tool
toolgroup_id: str
tool_host: ToolHost
description: str
parameters: list[ToolParameter]
metadata: dict[str, Any] | None = None
@json_schema_type
class ToolDef(BaseModel):
name: str
description: str | None = None
parameters: list[ToolParameter] | None = None
metadata: dict[str, Any] | None = None
@json_schema_type
class ToolGroupInput(BaseModel):
toolgroup_id: str
provider_id: str
args: dict[str, Any] | None = None
mcp_endpoint: URL | None = None
@json_schema_type
class ToolGroup(Resource):
type: Literal[ResourceType.tool_group] = ResourceType.tool_group
mcp_endpoint: URL | None = None
args: dict[str, Any] | None = None
@json_schema_type
class ToolInvocationResult(BaseModel):
content: InterleavedContent | None = None
error_message: str | None = None
error_code: int | None = None
metadata: dict[str, Any] | None = None
class ToolStore(Protocol):
async def get_tool(self, tool_name: str) -> Tool: ...
async def get_tool_group(self, toolgroup_id: str) -> ToolGroup: ...
class ListToolGroupsResponse(BaseModel):
data: list[ToolGroup]
class ListToolsResponse(BaseModel):
data: list[Tool]
class ListToolDefsResponse(BaseModel):
data: list[ToolDef]
@runtime_checkable
@trace_protocol
class ToolGroups(Protocol):
@webmethod(route="/toolgroups", method="POST")
async def register_tool_group(
self,
toolgroup_id: str,
provider_id: str,
mcp_endpoint: URL | None = None,
args: dict[str, Any] | None = None,
) -> None:
"""Register a tool group.
:param toolgroup_id: The ID of the tool group to register.
:param provider_id: The ID of the provider to use for the tool group.
:param mcp_endpoint: The MCP endpoint to use for the tool group.
:param args: A dictionary of arguments to pass to the tool group.
"""
...
@webmethod(route="/toolgroups/{toolgroup_id:path}", method="GET")
async def get_tool_group(
self,
toolgroup_id: str,
) -> ToolGroup:
"""Get a tool group by its ID.
:param toolgroup_id: The ID of the tool group to get.
:returns: A ToolGroup.
"""
...
@webmethod(route="/toolgroups", method="GET")
async def list_tool_groups(self) -> ListToolGroupsResponse:
"""List tool groups with optional provider.
:returns: A ListToolGroupsResponse.
"""
...
@webmethod(route="/tools", method="GET")
async def list_tools(self, toolgroup_id: str | None = None) -> ListToolsResponse:
"""List tools with optional tool group.
:param toolgroup_id: The ID of the tool group to list tools for.
:returns: A ListToolsResponse.
"""
...
@webmethod(route="/tools/{tool_name:path}", method="GET")
async def get_tool(
self,
tool_name: str,
) -> Tool:
"""Get a tool by its name.
:param tool_name: The name of the tool to get.
:returns: A Tool.
"""
...
@webmethod(route="/toolgroups/{toolgroup_id:path}", method="DELETE")
async def unregister_toolgroup(
self,
toolgroup_id: str,
) -> None:
"""Unregister a tool group.
:param toolgroup_id: The ID of the tool group to unregister.
"""
...
class SpecialToolGroup(Enum):
rag_tool = "rag_tool"
@runtime_checkable
@trace_protocol
class ToolRuntime(Protocol):
tool_store: ToolStore | None = None
rag_tool: RAGToolRuntime | None = None
# TODO: This needs to be renamed once OPEN API generator name conflict issue is fixed.
@webmethod(route="/tool-runtime/list-tools", method="GET")
async def list_runtime_tools(
self, tool_group_id: str | None = None, mcp_endpoint: URL | None = None
) -> ListToolDefsResponse:
"""List all tools in the runtime.
:param tool_group_id: The ID of the tool group to list tools for.
:param mcp_endpoint: The MCP endpoint to use for the tool group.
:returns: A ListToolDefsResponse.
"""
...
@webmethod(route="/tool-runtime/invoke", method="POST")
async def invoke_tool(self, tool_name: str, kwargs: dict[str, Any]) -> ToolInvocationResult:
"""Run a tool with the given arguments.
:param tool_name: The name of the tool to invoke.
:param kwargs: A dictionary of arguments to pass to the tool.
:returns: A ToolInvocationResult.
"""
...