@rcrsr/rill-ext-mcp

rill extension for Model Context Protocol (MCP) integration. Generates host functions dynamically from MCP server capabilities. Supports stdio and HTTP transports with static and dynamic authentication.

Experimental. Breaking changes will occur before stabilization.

Install

npm install @rcrsr/rill-ext-mcp

Peer dependencies: @rcrsr/rill

Quick Start

import { parse, execute, createRuntimeContext, prefixFunctions } from '@rcrsr/rill';
import { createMcpExtension } from '@rcrsr/rill-ext-mcp';

const ext = await createMcpExtension({
  transport: {
    type: 'stdio',
    command: 'npx',
    args: ['-y', '@modelcontextprotocol/server-filesystem', '/tmp'],
  },
});
const prefixed = prefixFunctions('fs', ext);
const { dispose, ...functions } = prefixed;

const ctx = createRuntimeContext({
  functions,
  callbacks: { onLog: (v) => console.log(v) },
});

const script = `fs::list_tools() -> log`;
const result = await execute(parse(script), ctx);

dispose?.();

Documentation

See full documentation for configuration, transport types, authentication patterns, error handling, and examples.

Related

• rill — Core language runtime
• Extensions Guide — Extension contract and patterns
• Host API Reference — Runtime context and host functions
• MCP Specification — Model Context Protocol documentation

License

MIT