@tanstack/ai-mcp/src/server/registry.ts

Host-side Model Context Protocol client for TanStack AI: discover and run MCP server tools, resources, and prompts in any adapter's chat() loop, with generated end-to-end types.

import type { MCPServerOptions } from './create-server'

// Keeps the options of each server for `directMCPClient`.
// This module imports nothing at runtime, so the client entry point can read
// the options without loading the server SDK.
const serverOptionsByServer = new WeakMap<object, MCPServerOptions>()

/** Internal. Records the options that `server` was created with. */
export function rememberServerOptions(
  server: object,
  options: MCPServerOptions,
) {
  serverOptionsByServer.set(server, options)
}

/** Internal. Returns the options that `server` was created with. */
export function optionsOfServer(server: object) {
  return serverOptionsByServer.get(server)
}

// A stdio process serves one client, so spec 2025 sessions cost nothing.
const stdioServers = new WeakSet<object>()

/** Internal. Records that `serveMCPStdio` serves `server`. */
export function markServedOverStdio(server: object) {
  stdioServers.add(server)
}

/** Internal. True when `serveMCPStdio` serves `server`. */
export function isServedOverStdio(server: object) {
  return stdioServers.has(server)
}