MCP Overview

Mastra supports the Model Context Protocol (MCP) , an open standard for connecting AI agents to external tools and resources. It serves as a universal plugin system, enabling agents to call tools regardless of language or hosting environment.

Mastra can also be used to author MCP servers, exposing agents, tools, and other structured resources via the MCP interface. These can then be accessed by any system or agent that supports the protocol.

Mastra currently supports two MCP classes:

MCPClient: Connects to one or many MCP servers to access their tools, resources, prompts, and handle elicitation requests.
MCPServer: Exposes Mastra tools, agents, workflows, prompts, and resources to MCP compatible clients.

Getting started

To use MCP, install the required dependency:


npm install @mastra/mcp@latest

Configuring `MCPClient`

The MCPClient connects Mastra primitives to external MCP servers, which can be local packages (invoked using npx) or remote HTTP(S) endpoints. Each server must be configured with either a command or a url, depending on how it’s hosted.

src/mastra/mcp/test-mcp-client.ts


import { MCPClient } from "@mastra/mcp";
 
export const testMcpClient = new MCPClient({
  id: "test-mcp-client",
  servers: {
    wikipedia: {
      command: "npx",
      args: ["-y", "wikipedia-mcp"]
    },
    weather: {
      url: new URL(`https://server.smithery.ai/@smithery-ai/national-weather-service/mcp?api_key=${process.env.SMITHERY_API_KEY}`)
    },
  }
});

See MCPClient for a full list of configuration options.

Using `MCPClient` with an agent

To use tools from an MCP server in an agent, import your MCPClient and call .getTools() in the tools parameter. This loads from the defined MCP servers, making them available to the agent.

src/mastra/agents/test-agent.ts


import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
 
import { testMcpClient } from "../mcp/test-mcp-client";
 
export const testAgent = new Agent({
  name: "Test Agent",
  description: "You are a helpful AI assistant",
  instructions: `
      You are a helpful assistant that has access to the following MCP Servers.
      - Wikipedia MCP Server
      - US National Weather Service
 
      Answer questions using the information you find using the MCP Servers.`,
  model: openai("gpt-4o-mini"),
  tools: await testMcpClient.getTools()
});

See the Agent Class for a full list of configuration options.

Configuring `MCPServer`

To expose agents, tools, and workflows from your Mastra application to external systems over HTTP(S) use the MCPServer class. This makes them accessible to any system or agent that supports the protocol.

src/mastra/mcp/test-mcp-server.ts


import { MCPServer } from "@mastra/mcp";
 
import { testAgent } from "../agents/test-agent";
import { testWorkflow } from "../workflows/test-workflow";
import { testTool } from "../tools/test-tool";
 
export const testMcpServer = new MCPServer({
  id: "test-mcp-server",
  name: "Test Server",
  version: "1.0.0",
  agents: { testAgent },
  tools: { testTool },
  workflows: { testWorkflow }
});

See MCPServer for a full list of configuration options.

Registering an `MCPServer`

To make an MCP server available to other systems or agents that support the protocol, register it in the main Mastra instance using mcpServers.

src/mastra/index.ts


import { Mastra } from "@mastra/core/mastra";
 
import { testMcpServer } from "./mcp/test-mcp-server";
 
export const mastra = new Mastra({
  // ...
  mcpServers: { testMcpServer }
});

Static and dynamic tools

MCPClient offers two approaches to retrieving tools from connected servers, suitable for different application architectures:

Feature	Static Configuration (`await mcp.getTools()`)	Dynamic Configuration (`await mcp.getToolsets()`)
Use Case	Single-user, static config (e.g., CLI tool)	Multi-user, dynamic config (e.g., SaaS app)
Configuration	Fixed at agent initialization	Per-request, dynamic
Credentials	Shared across all uses	Can vary per user/request
Agent Setup	Tools added in `Agent` constructor	Tools passed in `.generate()` or `.stream()` options

Static tools

Use the .getTools() method to fetch tools from all configured MCP servers. This is suitable when configuration (such as API keys) is static and consistent across users or requests. Call it once and pass the result to the tools property when defining your agent.

See getTools() for more information.

src/mastra/agents/test-agent.ts


import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
 
import { testMcpClient } from "../mcp/test-mcp-client";
 
export const testAgent = new Agent({
  // ...
  tools: await testMcpClient.getTools()
});

Dynamic tools

Use the .getToolsets() method when tool configuration may vary by request or user, such as in a multi-tenant system where each user provides their own API key. This method returns toolsets that can be passed to the toolsets option in the agent’s .generate() or .stream() calls.


import { MCPClient } from "@mastra/mcp";
import { mastra } from "./mastra";
 
async function handleRequest(userPrompt: string, userApiKey: string) {
  const userMcp = new MCPClient({
    servers: {
      weather: {
        url: new URL("http://localhost:8080/mcp"),
        requestInit: {
          headers: {
            Authorization: `Bearer ${userApiKey}`
          }
        }
      }
    }
  });
 
  const agent = mastra.getAgent("testAgent");
 
  const response = await agent.generate(userPrompt, {
    toolsets: await userMcp.getToolsets()
  });
 
  await userMcp.disconnect();
 
  return Response.json({
    data: response.text
  });
}

See getToolsets() for more information.

Connecting to an MCP registry

MCP servers can be discovered through registries. Here’s how to connect to some popular ones using MCPClient:

Klavis AI

Klavis AI provides hosted, enterprise-authenticated, high-quality MCP servers.


import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    salesforce: {
      url: new URL("https://salesforce-mcp-server.klavis.ai/mcp/?instance_id={private-instance-id}"),
    },
    hubspot: {
      url: new URL("https://hubspot-mcp-server.klavis.ai/mcp/?instance_id={private-instance-id}"),
    },
  },
});

Klavis AI offers enterprise-grade authentication and security for production deployments.

For more details on how to integrate Mastra with Klavis, check out their documentation .

mcp.run

mcp.run provides pre-authenticated, managed MCP servers. Tools are grouped into Profiles, each with a unique, signed URL.


import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    marketing: { // Example profile name
      url: new URL(process.env.MCP_RUN_SSE_URL!), // Get URL from mcp.run profile
    },
  },
});

Important: Treat the mcp.run SSE URL like a password. Store it securely, for example, in an environment variable.
.env
MCP_RUN_SSE_URL=https://www.mcp.run/api/mcp/sse?nonce=...

Composio.dev

Composio.dev offers a registry of SSE-based MCP servers . You can use the SSE URL generated for tools like Cursor directly.


import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    googleSheets: {
      url: new URL("https://mcp.composio.dev/googlesheets/[private-url-path]"),
    },
    gmail: {
      url: new URL("https://mcp.composio.dev/gmail/[private-url-path]"),
    },
  },
});

Authentication with services like Google Sheets often happens interactively through the agent conversation.

Note: Composio URLs are typically tied to a single user account, making them best suited for personal automation rather than multi-tenant applications.

Smithery.ai

Smithery.ai provides a registry accessible via their CLI.


// Unix/Mac
import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    sequentialThinking: {
      command: "npx",
      args: [
        "-y",
        "@smithery/cli@latest",
        "run",
        "@smithery-ai/server-sequential-thinking",
        "--config",
        "{}",
      ],
    },
  },
});


// Windows
import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    sequentialThinking: {
      command: "npx",
      args: [
        "-y",
        "@smithery/cli@latest",
        "run",
        "@smithery-ai/server-sequential-thinking",
        "--config",
        "{}",
      ],
    },
  },
});

Ampersand

Ampersand offers an MCP Server that allows you to connect your agent to 150+ integrations with SaaS products like Salesforce, Hubspot, and Zendesk.


 
// MCPClient with Ampersand MCP Server using SSE
export const mcp = new MCPClient({
    servers: {
    "@amp-labs/mcp-server": {
      "url": `https://mcp.withampersand.com/v1/sse?${new URLSearchParams({
        apiKey: process.env.AMPERSAND_API_KEY,
        project: process.env.AMPERSAND_PROJECT_ID,
        integrationName: process.env.AMPERSAND_INTEGRATION_NAME,
        groupRef: process.env.AMPERSAND_GROUP_REF
      })}`
    }
  }
});


// If you prefer to run the MCP server locally:
 
import { MCPClient } from "@mastra/mcp";
 
// MCPClient with Ampersand MCP Server using stdio transport
export const mcp = new MCPClient({
    servers: {
      "@amp-labs/mcp-server": {
        command: "npx",
        args: [
          "-y",
          "@amp-labs/mcp-server@latest",
          "--transport",
          "stdio",
          "--project",
          process.env.AMPERSAND_PROJECT_ID,
          "--integrationName",
          process.env.AMPERSAND_INTEGRATION_NAME,
          "--groupRef",
          process.env.AMPERSAND_GROUP_REF, // optional
        ],
        env: {
          AMPERSAND_API_KEY: process.env.AMPERSAND_API_KEY,
        },
      },
    },
});

As an alternative to MCP, Ampersand’s AI SDK also has an adapter for Mastra, so you can directly import Ampersand tools for your agent to access.

MCP Overview

Mastra currently supports two MCP classes:

MCPClient: Connects to one or many MCP servers to access their tools, resources, prompts, and handle elicitation requests.
MCPServer: Exposes Mastra tools, agents, workflows, prompts, and resources to MCP compatible clients.

Getting started

To use MCP, install the required dependency:


npm install @mastra/mcp@latest

Configuring `MCPClient`

src/mastra/mcp/test-mcp-client.ts


import { MCPClient } from "@mastra/mcp";
 
export const testMcpClient = new MCPClient({
  id: "test-mcp-client",
  servers: {
    wikipedia: {
      command: "npx",
      args: ["-y", "wikipedia-mcp"]
    },
    weather: {
      url: new URL(`https://server.smithery.ai/@smithery-ai/national-weather-service/mcp?api_key=${process.env.SMITHERY_API_KEY}`)
    },
  }
});

See MCPClient for a full list of configuration options.

Using `MCPClient` with an agent

To use tools from an MCP server in an agent, import your MCPClient and call .getTools() in the tools parameter. This loads from the defined MCP servers, making them available to the agent.

src/mastra/agents/test-agent.ts


import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
 
import { testMcpClient } from "../mcp/test-mcp-client";
 
export const testAgent = new Agent({
  name: "Test Agent",
  description: "You are a helpful AI assistant",
  instructions: `
      You are a helpful assistant that has access to the following MCP Servers.
      - Wikipedia MCP Server
      - US National Weather Service
 
      Answer questions using the information you find using the MCP Servers.`,
  model: openai("gpt-4o-mini"),
  tools: await testMcpClient.getTools()
});

See the Agent Class for a full list of configuration options.

Configuring `MCPServer`

src/mastra/mcp/test-mcp-server.ts


import { MCPServer } from "@mastra/mcp";
 
import { testAgent } from "../agents/test-agent";
import { testWorkflow } from "../workflows/test-workflow";
import { testTool } from "../tools/test-tool";
 
export const testMcpServer = new MCPServer({
  id: "test-mcp-server",
  name: "Test Server",
  version: "1.0.0",
  agents: { testAgent },
  tools: { testTool },
  workflows: { testWorkflow }
});

See MCPServer for a full list of configuration options.

Registering an `MCPServer`

To make an MCP server available to other systems or agents that support the protocol, register it in the main Mastra instance using mcpServers.

src/mastra/index.ts


import { Mastra } from "@mastra/core/mastra";
 
import { testMcpServer } from "./mcp/test-mcp-server";
 
export const mastra = new Mastra({
  // ...
  mcpServers: { testMcpServer }
});

Static and dynamic tools

MCPClient offers two approaches to retrieving tools from connected servers, suitable for different application architectures:

Feature	Static Configuration (`await mcp.getTools()`)	Dynamic Configuration (`await mcp.getToolsets()`)
Use Case	Single-user, static config (e.g., CLI tool)	Multi-user, dynamic config (e.g., SaaS app)
Configuration	Fixed at agent initialization	Per-request, dynamic
Credentials	Shared across all uses	Can vary per user/request
Agent Setup	Tools added in `Agent` constructor	Tools passed in `.generate()` or `.stream()` options

Static tools

See getTools() for more information.

src/mastra/agents/test-agent.ts


import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
 
import { testMcpClient } from "../mcp/test-mcp-client";
 
export const testAgent = new Agent({
  // ...
  tools: await testMcpClient.getTools()
});

Dynamic tools


import { MCPClient } from "@mastra/mcp";
import { mastra } from "./mastra";
 
async function handleRequest(userPrompt: string, userApiKey: string) {
  const userMcp = new MCPClient({
    servers: {
      weather: {
        url: new URL("http://localhost:8080/mcp"),
        requestInit: {
          headers: {
            Authorization: `Bearer ${userApiKey}`
          }
        }
      }
    }
  });
 
  const agent = mastra.getAgent("testAgent");
 
  const response = await agent.generate(userPrompt, {
    toolsets: await userMcp.getToolsets()
  });
 
  await userMcp.disconnect();
 
  return Response.json({
    data: response.text
  });
}

See getToolsets() for more information.

Connecting to an MCP registry

MCP servers can be discovered through registries. Here’s how to connect to some popular ones using MCPClient:

Klavis AI

Klavis AI provides hosted, enterprise-authenticated, high-quality MCP servers.


import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    salesforce: {
      url: new URL("https://salesforce-mcp-server.klavis.ai/mcp/?instance_id={private-instance-id}"),
    },
    hubspot: {
      url: new URL("https://hubspot-mcp-server.klavis.ai/mcp/?instance_id={private-instance-id}"),
    },
  },
});

Klavis AI offers enterprise-grade authentication and security for production deployments.

For more details on how to integrate Mastra with Klavis, check out their documentation .

mcp.run

mcp.run provides pre-authenticated, managed MCP servers. Tools are grouped into Profiles, each with a unique, signed URL.


import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    marketing: { // Example profile name
      url: new URL(process.env.MCP_RUN_SSE_URL!), // Get URL from mcp.run profile
    },
  },
});

Important: Treat the mcp.run SSE URL like a password. Store it securely, for example, in an environment variable.
.env
MCP_RUN_SSE_URL=https://www.mcp.run/api/mcp/sse?nonce=...

Composio.dev

Composio.dev offers a registry of SSE-based MCP servers . You can use the SSE URL generated for tools like Cursor directly.


import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    googleSheets: {
      url: new URL("https://mcp.composio.dev/googlesheets/[private-url-path]"),
    },
    gmail: {
      url: new URL("https://mcp.composio.dev/gmail/[private-url-path]"),
    },
  },
});

Authentication with services like Google Sheets often happens interactively through the agent conversation.

Note: Composio URLs are typically tied to a single user account, making them best suited for personal automation rather than multi-tenant applications.

Smithery.ai

Smithery.ai provides a registry accessible via their CLI.


// Unix/Mac
import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    sequentialThinking: {
      command: "npx",
      args: [
        "-y",
        "@smithery/cli@latest",
        "run",
        "@smithery-ai/server-sequential-thinking",
        "--config",
        "{}",
      ],
    },
  },
});


// Windows
import { MCPClient } from "@mastra/mcp";
 
const mcp = new MCPClient({
  servers: {
    sequentialThinking: {
      command: "npx",
      args: [
        "-y",
        "@smithery/cli@latest",
        "run",
        "@smithery-ai/server-sequential-thinking",
        "--config",
        "{}",
      ],
    },
  },
});

Ampersand

Ampersand offers an MCP Server that allows you to connect your agent to 150+ integrations with SaaS products like Salesforce, Hubspot, and Zendesk.


 
// MCPClient with Ampersand MCP Server using SSE
export const mcp = new MCPClient({
    servers: {
    "@amp-labs/mcp-server": {
      "url": `https://mcp.withampersand.com/v1/sse?${new URLSearchParams({
        apiKey: process.env.AMPERSAND_API_KEY,
        project: process.env.AMPERSAND_PROJECT_ID,
        integrationName: process.env.AMPERSAND_INTEGRATION_NAME,
        groupRef: process.env.AMPERSAND_GROUP_REF
      })}`
    }
  }
});


// If you prefer to run the MCP server locally:
 
import { MCPClient } from "@mastra/mcp";
 
// MCPClient with Ampersand MCP Server using stdio transport
export const mcp = new MCPClient({
    servers: {
      "@amp-labs/mcp-server": {
        command: "npx",
        args: [
          "-y",
          "@amp-labs/mcp-server@latest",
          "--transport",
          "stdio",
          "--project",
          process.env.AMPERSAND_PROJECT_ID,
          "--integrationName",
          process.env.AMPERSAND_INTEGRATION_NAME,
          "--groupRef",
          process.env.AMPERSAND_GROUP_REF, // optional
        ],
        env: {
          AMPERSAND_API_KEY: process.env.AMPERSAND_API_KEY,
        },
      },
    },
});

As an alternative to MCP, Ampersand’s AI SDK also has an adapter for Mastra, so you can directly import Ampersand tools for your agent to access.

MCP Overview

Getting started

Configuring MCPClient

Using MCPClient with an agent

Configuring MCPServer

Registering an MCPServer

Static and dynamic tools

Static tools

Dynamic tools

Connecting to an MCP registry

Klavis AI

mcp.run

Composio.dev

Smithery.ai

Ampersand

Related

MCP Overview

Getting started

Configuring MCPClient

Using MCPClient with an agent

Configuring MCPServer

Registering an MCPServer

Static and dynamic tools

Static tools

Dynamic tools

Connecting to an MCP registry

Klavis AI

mcp.run

Composio.dev

Smithery.ai

Ampersand

Related

Configuring `MCPClient`

Using `MCPClient` with an agent

Configuring `MCPServer`

Registering an `MCPServer`

Configuring `MCPClient`

Using `MCPClient` with an agent

Configuring `MCPServer`

Registering an `MCPServer`