Async timer AI Agent tool | Resonate example application

This example shows a minimal example of Resonate + MCP.

To use Resonate in an MCP Server, the MCP Server needs to be run using "streamable-http" as the transport.

Therefore, you need a stdio -> streamable-http proxy running for Claude to talk to.

proxy

from fastmcp import FastMCP

# Create a proxy to a remote server
proxy = FastMCP.as_proxy(
    "http://localhost:5001/mcp",  # URL of the remote server
    name="Remote Server Proxy"
)


if __name__ == "__main__":
    proxy.run()  # Runs via STDIO for Claude Desktop

To run the proxy:

uv run proxy.py

claude_desktop_config.json

Make sure Claude's config points at the proxy.

{
  "mcpServers": {
    "timer": {
      "command": "uv", // or /opt/homebrew/bin/uv
      "args": [
        "--directory",
        "/FULL/PATH/TO/YOUR/TOOL/DIRECTORY/example-agent-tool-async-timer",
        "run",
        "proxy.py"
      ]
    }
  }
}

You should restart Claude desktop after changing this config.

On the MCP Server, make sure you return a promise ID - instead of blocking on a result. Claude can then use the promise ID to check for the result at any point later on.

timer mcp server

The function that runs in the background is registered with resonate.register(timer).

timer function

async def timer(ctx: Context, timer_name: str, seconds: int) -> str:
    print(f"Timer started: {timer_name} for {seconds} seconds", flush=True)
    await ctx.sleep(int(seconds))
    return "complete"

resonate.register(timer)

The functions that Claude interacts with are decorated with @mcp.tool

set timer tool

@mcp.tool()
def set_timer(timer_name: str, seconds: int) -> dict:
    # tool description

    resonate.run(timer_name, timer, timer_name, seconds)
    return {"promise_id": timer_name}

get timer status tool

@mcp.tool()
async def get_timer_status(timer_name: str) -> dict:
    # tool description

    promise_id = f"{timer_name}"
    handle = await resonate.get(promise_id)
    if not handle.done():
        return {"status": "running"}
    return {"status": await handle.result()}

To run the MCP server:

uv run timer.py