MCP Client

Last updated 2026-10-31

Agenvoy's MCP client lets agents call tools exposed by any MCP server. Client and server share one package (internal/runtime/mcp) built on the official modelcontextprotocol/go-sdk.

Configuration layout

One file. The session-scoped layer was removed — every client reads the same config:

~/.config/agenvoy/mcp.json

JSON format

{
  "servers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": { "GITHUB_TOKEN": "${GITHUB_TOKEN}" }
    },
    "remote-api": {
      "url": "https://api.example.com/mcp",
      "headers": { "Authorization": "Bearer ${TOKEN}" }
    }
  }
}

command and url are mutually exclusive. ${VAR} / $VAR placeholders inside env, headers, and args are expanded with os.ExpandEnv at startup.

Transport types

Both transports are handled by the SDK; Agenvoy only supplies the command or the endpoint plus a header-injecting HTTP client.

Management

The add flow asks for the server name, transport (Local stdio / Remote HTTP), and the type-specific fields. There are no agen mcp CLI subcommands. Since v1.2.0 the TUI opens no MCP connections of its own: /mcp status, reconnect, tools and remove (disconnect) are sent to the daemon over its Unix socket (~/.config/agenvoy/daemon.sock), which owns every MCP client.

OAuth for HTTP servers

A server marked auth: oauth logs in through mcp.Login: the daemon opens a loopback callback listener on localhost:17988, performs dynamic client registration when the provider allows it, and stores the resulting token and client id in the OS keychain. When the provider rejects dynamic registration, supply a pre-registered client with POST /v1/mcp/oauth/client (redirect_uri defaults to http://localhost:17988/callback and must match the provider console exactly). When the browser cannot reach the listener, paste the redirect URL back with POST /v1/mcp/oauth/callback.

Recommended servers

Zero-auth, locally executed (no API key required):

Avoid registering MCP servers whose capabilities overlap with built-in tools (e.g., filesystem, git, fetch, shell) — duplicates only inflate the LLM tool list.