fix: support MCP Python SDK v2

CLAUDE.md

@@ -47,7 +47,7 @@ The daemon idle-exits after `daemon.idle_timeout_minutes` (default 180, 0 = neve
 
 **`settings.py`** — YAML config loading for both global (`~/.cocoindex_code/global_settings.yml`) and per-project (`.cocoindex_code/settings.yml`) settings. Also provides all path helpers (`cocoindex_db_path`, `target_sqlite_db_path`, `resolve_db_dir`, etc.) and host-path-mapping logic for Docker.
 
-**`server.py`** — FastMCP wrapper that delegates `search` calls to the daemon client. Also contains the legacy `main()` entry point (`cocoindex-code` command) for backward-compatible env-var-based configuration.
+**`server.py`** — MCPServer wrapper that delegates `search` calls to the daemon client. Also contains the legacy `main()` entry point (`cocoindex-code` command) for backward-compatible env-var-based configuration.
 
 **`cli.py`** — Typer app with `ccc` subcommands (`init`, `index`, `search`, `grep`, `status`, `reset`, `doctor`, `mcp`, `daemon status/restart/stop`). CLI logic only — delegates to `client.py` or `grep.py`.
 

pyproject.toml

@@ -22,7 +22,7 @@ classifiers = [
 ]
 
 dependencies = [
-    "mcp>=1.0.0",
+    "mcp>=2.0.0,<3",
     "cocoindex[litellm]>=1.0.13,<1.1.0",
     "sqlite-vec>=0.1.0",
     "pydantic>=2.0.0",

src/cocoindex_code/server.py

@@ -14,7 +14,7 @@
 import os
 from pathlib import Path
 
-from mcp.server.fastmcp import FastMCP
+from mcp.server.mcpserver import MCPServer
 from pydantic import BaseModel, Field
 
 from .settings import DaemonSettings, load_user_settings
@@ -58,9 +58,9 @@ class SearchResultModel(BaseModel):
 # === Daemon-backed MCP server factory ===
 
 
-def create_mcp_server(project_root: str) -> FastMCP:
+def create_mcp_server(project_root: str) -> MCPServer:
     """Create a lightweight MCP server that delegates to the daemon."""
-    mcp = FastMCP("cocoindex-code", instructions=_MCP_INSTRUCTIONS)
+    mcp = MCPServer("cocoindex-code", instructions=_MCP_INSTRUCTIONS)
 
     @mcp.tool(
         name="search",
@@ -201,7 +201,7 @@ async def run_heartbeat_loop() -> None:
 
 
 # Keep the old `mcp` global for backward compatibility in __init__.py
-mcp: FastMCP | None = None
+mcp: MCPServer | None = None
 
 
 # === Backward-compatible entry point ===

tests/test_server.py

@@ -0,0 +1,31 @@
+import pytest
+from mcp import Client
+
+from cocoindex_code import client as daemon_client
+from cocoindex_code.protocol import SearchResponse
+from cocoindex_code.server import create_mcp_server
+
+
+async def test_mcp_server_uses_v2_protocol(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setattr(
+        daemon_client,
+        "search",
+        lambda **kwargs: SearchResponse(success=True, offset=kwargs["offset"]),
+    )
+
+    server = create_mcp_server(".")
+    async with Client(server, raise_exceptions=True) as client:
+        tools = await client.list_tools()
+        result = await client.call_tool(
+            "search",
+            {"query": "authentication", "refresh_index": False},
+        )
+
+    assert [tool.name for tool in tools.tools] == ["search"]
+    assert result.structured_content == {
+        "success": True,
+        "results": [],
+        "total_returned": 0,
+        "offset": 0,
+        "message": None,
+    }