feat: support MCP bridge

[sigoden]

Let MCP tools be used by LLM functions.

Get Started

1. Create a mpc.json at <llm-functions-dir>.

{
  "mcpServers": {
    "sqlite": {
      "command": "uvx",
      "args": [
        "mcp-server-sqlite",
        "--db-path",
        "/tmp/foo.db"
      ]
    },
    "github": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-github"
      ],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "<YOUR_TOKEN>"
      }
    }
  }
}

MCP-Bridge will launch the server and register all the tools listed by the server. The tool identifier will be server_toolname to avoid clashes.

2. Run the bridge server, build mcp tool binaries, update functions.json, all with:

argc mcp start

Run argc mcp stop to stop the bridge server, recover functions.json

argc mcp

$ argc mcp --help
USAGE: mcp <COMMAND>

COMMANDS:
  start               Start/Restart mcp bridge server
  stop                Stop mcp bridge server
  call                Call mcp tool
  logs                Show logs
  build-bin           Build tools to bin
  merge-functions     Merge mcp tools into functions.json
  unmerge-functions   Unmerge mcp tools from functions.json
  build-declarations  Build tools to bin
  wait-for-server     Wait for mcp bridge server to ready