@useatlas/mcp

Reference implementation of AtlasInteractionPlugin from @useatlas/plugin-sdk.

Manages the lifecycle (init, health, teardown) of the @atlas/mcp server as a plugin, proving the interaction plugin interface works with a real integration. Tool bridging and resource registration are handled internally by @atlas/mcp — this plugin is a thin lifecycle wrapper.

Usage

// atlas.config.ts
import { defineConfig } from "@atlas/api/lib/config";
import { mcpPlugin } from "@useatlas/mcp";

export default defineConfig({
  plugins: [
    mcpPlugin({ transport: "stdio" }),
  ],
});

Config Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | transport | "stdio" \| "sse" | "stdio" | Transport type. stdio uses stdin/stdout (JSON-RPC) | | port | number | — | Port for SSE transport (ignored for stdio) |

Transport Support

• stdio (default) — Communicates via stdin/stdout JSON-RPC. Used by Claude Desktop, Cursor, and other MCP-compatible clients. Fully implemented.
• sse — Server-Sent Events over HTTP. Defined in config type for future implementation.

Interface Change

This reference implementation revealed that AtlasInteractionPlugin.routes should be optional. MCP's primary transport (stdio) doesn't involve HTTP routes — making routes mandatory would force stdio-based interaction plugins to provide a meaningless no-op.

Change: routes on AtlasInteractionPlugin is now optional (routes?: (app: Hono) => void). Plugins that don't need HTTP routes (stdio transports, CLI interfaces) can omit it entirely. Plugins that do need routes (Slack bot, SSE-based MCP, webhooks) still provide them as before.

Standalone Usage

The @atlas/mcp package continues to work standalone without the plugin wrapper:

bun run mcp             # Start MCP server on stdio
bun run dev:mcp         # Start MCP server with hot reload
bun run atlas -- mcp    # Start via CLI

The plugin is an additive wrapper for use with atlas.config.ts — it does not replace the standalone entry points.