Turn Any OpenAPI into an MCP Server

import express from "express";
import { buildMcpServer, loadOpenApiSpec, attachSseRoutes } from "@powerduck/openapi-mcp-server";

// Load the OpenAPI document once (JSON or YAML)
const spec = await loadOpenApiSpec("./openapi.json");

// SpecProvider: () => Document | null
// ContextProvider: () => ExecutionContext
// BuildMcpServerOptions: { protocol?, name?, version?, pageSize?, instructions? }
const mcp = buildMcpServer(
  () => spec,                              // specProvider (required)
  () => ({                                 // contextProvider (optional)
    baseUrlOverride: "https://api.example.com/v1",
    upstreamHeaders: { "X-Service": "mcp-gateway" },
    requestTimeoutMs: 30000,
    security: { bearerToken: "upstream-token" },
    correlationId: "req-123",
    onLog: (entry) => console.log(entry.level, entry.message),
  }),
  {                                        // BuildMcpServerOptions (optional)
    name: "My API MCP Server",
    version: "1.0.0",
    pageSize: 100,                        // Max tools per list response
    instructions: "Use these tools to interact with the My API.",
  },
);

// Attach SSE routes to an Express app
const app = express();
attachSseRoutes(app, () => spec, () => ({}));
app.listen(3000, () => console.log("MCP SSE server on :3000"));

import { loadOpenApiSpec, startStdioServer } from "@powerduck/openapi-mcp-server";

// Load the OpenAPI document
const spec = await loadOpenApiSpec("./openapi.yaml");

// Start stdio server (pass the document directly)
await startStdioServer(spec, {}, { name: "My API" });

import { loadOpenApiSpec, generateTools, generatePrompts, generateResources } from "@powerduck/openapi-mcp-server";

const spec = await loadOpenApiSpec("./openapi.json");

const tools = generateTools(spec);           // MCP Tool[]
const prompts = generatePrompts(spec);       // GeneratedPrompt[]
const resources = generateResources(spec); // GeneratedResource[]

console.log(`Generated ${tools.length} tools, ${prompts.length} prompts, ${resources.length} resources`);

import { startAdminServer } from "@powerduck/openapi-mcp-server";

// Full ServerConfig — all fields shown
await startAdminServer({
  port: 8080,                            // REQUIRED: TCP port (0-65535)
  host: "127.0.0.1",                    // Bind interface (default: 127.0.0.1)
  apiKey: "mcp_secret_123",              // Shared secret for admin API
  specPath: "./openapi.json",             // Spec loaded at startup
  baseUrlOverride: "https://api.example.com/v1", // Override servers[0].url
  upstreamHeaders: { "X-Service": "mcp-admin" }, // Headers on every upstream request
  requestTimeoutMs: 30000,               // Per-request upstream timeout
  persistState: true,                    // Persist spec across restarts
  stateFilePath: "./mcp-state.json",      // Persisted state location
  allowedOrigins: ["https://app.example.com"], // CORS allowed origins
  allowedHosts: ["localhost", "127.0.0.1"],
  maxLogEntries: 1000,                   // Max in-memory log entries
  redactSensitiveHeaders: true,           // Redact auth headers in logs
  redactHeaderNames: ["X-Internal-Token"], // Additional headers to redact
  security: {                             // Credentials forwarded to upstream
    bearerToken: "upstream-bearer",
    basicAuth: { username: "admin", password: "secret" },
    apiKeys: { "X-API-Key": "key-value" },
  },
});
console.log("Admin UI at http://localhost:8080");