From 29ef0f419f7a87ce6f0d48b6e434458ec327c20f Mon Sep 17 00:00:00 2001
From: Paul Kompfner <paul@daily.co>
Date: Mon, 3 Nov 2025 22:19:07 -0500
Subject: [PATCH] Add typing formalizing `MCPClient` support for registering
 tools on an `LLMSwitcher` in addition to an `LLMService`.

---
 CHANGELOG.md                        | 20 ++++++++++++++------
 src/pipecat/services/mcp_service.py |  7 +++++--
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2f5aba6f2..411e381af 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,20 @@ reason")`.
   `LLMSwitcher.register_function()` in that it's a shorthand for registering
   functions on all LLMs in the switcher, but for direct functions.
 
+- Added support for passing in an `LLMSwicher` to `MCPClient.register_tools()`
+  (as well as the new `MCPClient.register_tools_schema()`).
+
+- Added `LLMSwitcher.register_direct_function()`. It works much like
+  `LLMSwitcher.register_function()` in that it's a shorthand for registering
+  a function on all LLMs in the switcher, except it takes a direct function (a
+  `FunctionSchema`-less function).
+
+- Added the two-step `MCPClient.get_tools_schema()` and
+  `MCPClient.register_tools_schema()` as two-step alternative to
+  `MCPClient.register_tools()`, to allow users to use `MCPClient` alongside
+  the pattern of passing in tools to the LLM service constructor (a pattern
+  supported by speech-to-speech services such as `GeminiLiveLLMService`).
+
 ### Changed
 
 - Bumped the `fastapi` dependency's upperbound to `<0.122.0`.
@@ -57,12 +71,6 @@ reason")`.
   supported languages before Pipecat's service classes are updated, while still
   providing guidance on verified languages.
 
-- Added the two-step `MCPClient.get_tools_schema()` and
-  `MCPClient.register_tools_schema()` as two-step alternative to
-  `MCPClient.register_tools()`, to allow users to use `MCPClient` alongside
-  the pattern of passing in tools to the LLM service constructor (a pattern
-  supported by speech-to-speech services such as `GeminiLiveLLMService`).
-
 ### Fixed
 
 - Fixed an issue where the `SmallWebRTCRequest` dataclass in runner would scrub
diff --git a/src/pipecat/services/mcp_service.py b/src/pipecat/services/mcp_service.py
index e38ea17b1..ccfb47adb 100644
--- a/src/pipecat/services/mcp_service.py
+++ b/src/pipecat/services/mcp_service.py
@@ -13,6 +13,7 @@ from loguru import logger
 
 from pipecat.adapters.schemas.function_schema import FunctionSchema
 from pipecat.adapters.schemas.tools_schema import ToolsSchema
+from pipecat.pipeline.llm_switcher import LLMSwitcher
 from pipecat.services.llm_service import FunctionCallParams, LLMService
 from pipecat.utils.base_object import BaseObject
 
@@ -74,7 +75,7 @@ class MCPClient(BaseObject):
                 f"{self} invalid argument type: `server_params` must be either StdioServerParameters, SseServerParameters, or StreamableHttpParameters."
             )
 
-    async def register_tools(self, llm) -> ToolsSchema:
+    async def register_tools(self, llm: LLMService | LLMSwitcher) -> ToolsSchema:
         """Register all available MCP tools with an LLM service.
 
         Connects to the MCP server, discovers available tools, converts their
@@ -106,7 +107,9 @@ class MCPClient(BaseObject):
         tools_schema = await self._list_tools()
         return tools_schema
 
-    async def register_tools_schema(self, tools_schema: ToolsSchema, llm: LLMService) -> None:
+    async def register_tools_schema(
+        self, tools_schema: ToolsSchema, llm: LLMService | LLMSwitcher
+    ) -> None:
         """Register the MCP tools (previously obtained from get_tools_schema()) with the LLM service.
 
         Args: