Arcade MCP (MCP Server SDK) - TypeScript Overview

// Main exports
import { MCPApp, tool } from 'arcade-mcp';
import { NotFoundError, RetryableToolError, FatalToolError } from 'arcade-mcp';
 
// Auth providers
import { Google, GitHub, Slack } from 'arcade-mcp/auth';
 
// Error adapters
import { SlackErrorAdapter, GoogleErrorAdapter } from 'arcade-mcp/adapters';

// server.ts
import { MCPApp } from 'arcade-mcp';
import { z } from 'zod';
 
const app = new MCPApp({ name: 'my-server', version: '1.0.0' });
 
app.tool('greet', {
  description: 'Greet a person by name',
  input: z.object({
    name: z.string().describe('The name of the person to greet'),
  }),
  handler: ({ input }) => `Hello, ${input.name}!`,
});
 
app.run({ transport: 'http', port: 8000, reload: true });

new MCPApp(options?: MCPAppOptions)

interface MCPAppOptions {
  /** Server name shown to AI clients */
  name?: string;
 
  /** Server version */
  version?: string;
 
  /** Human-readable title */
  title?: string;
 
  /** Usage instructions for AI clients */
  instructions?: string;
 
  /** Logging level */
  logLevel?: 'DEBUG' | 'INFO' | 'WARNING' | 'ERROR';
 
  /** Transport type: 'stdio' for Claude Desktop, 'http' for web */
  transport?: 'stdio' | 'http';
 
  /** HTTP host (auto-selects HTTP transport if set) */
  host?: string;
 
  /** HTTP port (auto-selects HTTP transport if set) */
  port?: number;
 
  /** Hot reload on file changes (development only) */
  reload?: boolean;
}

app.tool(name: string, options: ToolOptions): void

interface ToolOptions<
  TInput,
  TSecrets extends string = string,
  TAuth extends AuthProvider | undefined = undefined
> {
  /** Tool description for AI clients */
  description?: string;
 
  /** Zod schema for input validation */
  input: z.ZodType<TInput>;
 
  /** Tool handler function — authorization is non-optional when requiresAuth is set */
  handler: (
    context: ToolContext<TInput, TSecrets, TAuth extends AuthProvider ? true : false>
  ) => unknown | Promise<unknown>;
 
  /** OAuth provider for user authentication */
  requiresAuth?: TAuth;
 
  /** Secret keys required by this tool (use `as const` for type safety) */
  requiresSecrets?: readonly TSecrets[];
 
  /** Metadata keys required from the client */
  requiresMetadata?: string[];
 
  /** Error adapters for translating upstream errors (e.g., Slack, Google APIs) */
  adapters?: ErrorAdapter[];
}

handler: ({ input, authorization, getSecret, getMetadata }) => {
  // input         — Validated input matching your Zod schema
  // authorization — OAuth token/provider (TypeScript narrows to non-optional when requiresAuth is set)
  // getSecret     — Retrieve secrets (type-safe with `as const`)
  // getMetadata   — Retrieve metadata from the client
}

app.run(options?: RunOptions): Promise<void>

interface RunOptions {
  transport?: 'stdio' | 'http';
  host?: string;
  port?: number;
  reload?: boolean;
}

// tools/math.ts
import { tool } from 'arcade-mcp';
import { z } from 'zod';
 
export const add = tool({
  description: 'Add two numbers',
  input: z.object({ a: z.number(), b: z.number() }),
  handler: ({ input }) => input.a + input.b,
});
 
export const multiply = tool({
  description: 'Multiply two numbers',
  input: z.object({ a: z.number(), b: z.number() }),
  handler: ({ input }) => input.a * input.b,
});

// server.ts
import * as mathTools from './tools/math';
 
app.addToolsFromModule(mathTools);

export const calculator = tool({
  name: 'basic-calculator',  // explicit name overrides 'calculator'
  description: 'Basic arithmetic',
  input: z.object({
    operation: z.enum(['add', 'subtract', 'multiply', 'divide']),
    a: z.number(),
    b: z.number(),
  }),
  handler: ({ input }) => {
    const { operation, a, b } = input;
    switch (operation) {
      case 'add': return a + b;
      case 'subtract': return a - b;
      case 'multiply': return a * b;
      case 'divide': return a / b;
    }
  },
});

import { tool } from 'arcade-mcp';
import { z } from 'zod';
 
// Create and add a tool at runtime
const dynamicTool = tool({
  name: 'dynamic-tool',  // name required for runtime registration
  description: 'Added at runtime',
  input: z.object({ value: z.string() }),
  handler: ({ input }) => `Got: ${input.value}`,
});
 
await app.tools.add(dynamicTool);
 
// Remove a tool
await app.tools.remove('dynamic-tool');
 
// List all tools
const tools = await app.tools.list();

// Add a prompt (reusable message templates for AI clients)
await app.prompts.add(prompt, handler);
 
// Add a resource (files, data, or content the AI can read)
await app.resources.add(resource);

import { MCPApp } from 'arcade-mcp';
import { z } from 'zod';
 
const app = new MCPApp({ name: 'example-server' });
 
app.tool('echo', {
  description: 'Echo the text back',
  input: z.object({
    text: z.string().describe('The text to echo'),
  }),
  handler: ({ input }) => `Echo: ${input.text}`,
});
 
app.run({ transport: 'http', host: '0.0.0.0', port: 8000 });

import { MCPApp } from 'arcade-mcp';
import { Google } from 'arcade-mcp/auth';
import { z } from 'zod';
 
const app = new MCPApp({ name: 'my-server' });
 
app.tool('getProfile', {
  description: 'Get user profile from Google',
  input: z.object({
    userId: z.string(),
  }),
  requiresAuth: Google({ scopes: ['profile'] }),
  requiresSecrets: ['API_KEY'] as const,  // as const enables type-safe getSecret()
  handler: async ({ input, authorization, getSecret }) => {
    const token = authorization.token;      // User's OAuth token
    const apiKey = getSecret('API_KEY');    // ✅ Type-safe, autocomplete works
    // getSecret('OTHER');                  // ❌ TypeScript error: not in requiresSecrets
    return { userId: input.userId };
  },
});
 
app.run();

app.tool('contextAware', {
  description: 'A tool that uses client context',
  input: z.object({ query: z.string() }),
  requiresMetadata: ['sessionId', 'userAgent'],
  handler: ({ input, getMetadata }) => {
    const sessionId = getMetadata('sessionId');  // string | undefined
    return `Processing ${input.query} for session ${sessionId}`;
  },
});

app.tool('search', {
  description: 'Search the knowledge base',
  input: z.object({
    query: z.string().describe('Search query'),
    limit: z.number()
      .int()
      .min(1)
      .max(100)
      .default(10)
      .meta({
        title: 'Result limit',
        examples: [10, 25, 50],
      }),
  }),
  handler: ({ input }) => searchKnowledgeBase(input.query, input.limit),
});

import { MCPApp, NotFoundError } from 'arcade-mcp';
import { z } from 'zod';
 
const app = new MCPApp({ name: 'api-server' });
 
app.tool('getUser', {
  description: 'Fetch a user by ID',
  input: z.object({
    id: z.string().uuid().describe('User ID'),
  }),
  handler: async ({ input }) => {
    const user = await db.users.find(input.id);
 
    if (!user) {
      throw new NotFoundError(`User ${input.id} not found`);
    }
 
    return user;
  },
});

import { MCPApp } from 'arcade-mcp';
import { Google } from 'arcade-mcp/auth';
import { z } from 'zod';
 
const app = new MCPApp({
  name: 'full-example',
  version: '1.0.0',
  instructions: 'Use these tools to manage documents.',
  logLevel: 'DEBUG',
});
 
// Simple tool
app.tool('ping', {
  description: 'Health check',
  input: z.object({}),
  handler: () => 'pong',
});
 
// Complex tool with auth and secrets
app.tool('createDocument', {
  description: 'Create a new document in Google Drive',
  input: z.object({
    title: z.string().min(1).describe('Document title'),
    content: z.string().describe('Document content'),
    folder: z.string().optional().describe('Parent folder ID'),
  }),
  requiresAuth: Google({ scopes: ['drive.file'] }),
  requiresSecrets: ['DRIVE_API_KEY'] as const,
  handler: async ({ input, authorization, getSecret }) => {
    const response = await createDriveDocument({
      token: authorization.token,
      apiKey: getSecret('DRIVE_API_KEY'),
      ...input,
    });
    return { documentId: response.id, url: response.webViewLink };
  },
});
 
// Start server
if (import.meta.main) {
  app.run({ transport: 'http', host: '0.0.0.0', port: 8000 });
}