OpenHands/docs/usage/mcp.mdx

---
title: Model Context Protocol (MCP)
description: This page outlines how to configure and use the Model Context Protocol (MCP) in OpenHands, allowing you
  to extend the agent's capabilities with custom tools.
---

## Overview

Model Context Protocol (MCP) is a mechanism that allows OpenHands to communicate with external tool servers. These
servers can provide additional functionality to the agent, such as specialized data processing, external API access,
or custom tools. MCP is based on the open standard defined at [modelcontextprotocol.io](https://modelcontextprotocol.io).

<Note>
MCP is currently not available on OpenHands Cloud. This feature is only available when running OpenHands locally.
</Note>

### How MCP Works

When OpenHands starts, it:

1. Reads the MCP configuration.
2. Connects to any configured SSE and SHTTP servers.
3. Starts any configured stdio servers.
4. Registers the tools provided by these servers with the agent.

The agent can then use these tools just like any built-in tool. When the agent calls an MCP tool:

1. OpenHands routes the call to the appropriate MCP server.
2. The server processes the request and returns a response.
3. OpenHands converts the response to an observation and presents it to the agent.

## Configuration

MCP configuration can be defined in:
* The OpenHands UI through the Settings under the `MCP` tab.
* The `config.toml` file under the `[mcp]` section if not using the UI.

### Configuration Example via config.toml

```toml
[mcp]
# SSE Servers - External servers that communicate via Server-Sent Events
sse_servers = [
    # Basic SSE server with just a URL
    "http://example.com:8080/mcp",

    # SSE server with API key authentication
    {url="https://secure-example.com/mcp", api_key="your-api-key"}
]

# SHTTP Servers - External servers that communicate via Streamable HTTP
shttp_servers = [
    # Basic SHTTP server with just a URL
    "http://example.com:8080/mcp",

    # SHTTP server with API key authentication
    {url="https://secure-example.com/mcp", api_key="your-api-key"}
]

# Stdio Servers - Local processes that communicate via standard input/output
stdio_servers = [
    # Basic stdio server
    {name="fetch", command="uvx", args=["mcp-server-fetch"]},

    # Stdio server with environment variables
    {
        name="data-processor",
        command="python",
        args=["-m", "my_mcp_server"],
        env={
            "DEBUG": "true",
            "PORT": "8080"
        }
    }
]
```

## Configuration Options

### SSE Servers

SSE servers are configured using either a string URL or an object with the following properties:

- `url` (required)
  - Type: `str`
  - Description: The URL of the SSE server

- `api_key` (optional)
  - Type: `str`
  - Description: API key for authentication

### SHTTP Servers

SHTTP (Streamable HTTP) servers are configured using either a string URL or an object with the following properties:

- `url` (required)
  - Type: `str`
  - Description: The URL of the SHTTP server

- `api_key` (optional)
  - Type: `str`
  - Description: API key for authentication

### Stdio Servers

Stdio servers are configured using an object with the following properties:

- `name` (required)
  - Type: `str`
  - Description: A unique name for the server

- `command` (required)
  - Type: `str`
  - Description: The command to run the server

- `args` (optional)
  - Type: `list of str`
  - Default: `[]`
  - Description: Command-line arguments to pass to the server

- `env` (optional)
  - Type: `dict of str to str`
  - Default: `{}`
  - Description: Environment variables to set for the server process

## Transport Protocols

OpenHands supports three different MCP transport protocols:

### Server-Sent Events (SSE)
SSE is a legacy HTTP-based transport that uses Server-Sent Events for server-to-client communication and HTTP POST requests for client-to-server communication. This transport is suitable for basic streaming scenarios but has limitations in session management and connection resumability.

### Streamable HTTP (SHTTP)
SHTTP is the modern HTTP-based transport protocol that provides enhanced features over SSE:

- **Improved Session Management**: Supports stateful sessions with session IDs for maintaining context across requests
- **Connection Resumability**: Can resume broken connections and replay missed messages using event IDs
- **Bidirectional Communication**: Uses HTTP POST for client-to-server and optional SSE streams for server-to-client communication
- **Better Error Handling**: Enhanced error reporting and recovery mechanisms

SHTTP is the recommended transport for HTTP-based MCP servers as it provides better reliability and features compared to the legacy SSE transport.

### Standard Input/Output (stdio)
Stdio transport enables communication through standard input and output streams, making it ideal for local integrations and command-line tools. This transport is used for locally executed MCP servers that run as separate processes.