HomeRun AI Coding Agents in CoderMCP Server

MCP Server

Coder includes a built-in Model Context Protocol (MCP) server that provides AI assistants with tools and context about your Coder deployment. This enables AI-powered workflows for managing workspaces, templates, and development environments.

Coder supports two MCP server modes:

Local MCP Server: Runs via the Coder CLI using stdio transport. Ideal for local AI tools and IDE integrations.
Remote MCP Server: HTTP-based server exposed by your Coder deployment. Supports OAuth2 authentication and is published to the MCP Registry.

Local MCP Server

The local MCP server runs via the Coder CLI and uses stdio transport to communicate with AI tools.

Setup

Run the MCP server using the Coder CLI:

coder exp mcp server

Client Configuration

Configure your MCP client to spawn the Coder CLI:

{
  "mcpServers": {
    "coder": {
      "command": "coder",
      "args": ["exp", "mcp", "server"]
    }
  }
}

The CLI automatically uses your existing Coder authentication (from coder login).

Claude Desktop Example

Add to your Claude Desktop configuration file:

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "coder": {
      "command": "coder",
      "args": ["exp", "mcp", "server"]
    }
  }
}

Remote MCP Server

The remote MCP server is an HTTP endpoint exposed by your Coder deployment at /api/experimental/mcp/http. This enables MCP clients to connect to Coder without running the CLI locally.

Prerequisites

The remote MCP HTTP endpoint requires both the oauth2 and mcp-server-http experiments enabled on your Coder deployment:

coder server --experiments=oauth2,mcp-server-http

Or set the environment variable:

CODER_EXPERIMENTS=oauth2,mcp-server-http

MCP Registry

Coder is published to the official MCP Registry as io.github.coder/coder, enabling easy installation in supported MCP clients.

VS Code / GitHub Copilot

Open VS Code Command Palette and run MCP: Add Server...
Select From MCP Registry
Search for "Coder" and select it
Enter your Coder deployment hostname when prompted (e.g., coder.example.com)
VS Code will automatically handle OAuth2 authentication

Claude Desktop (Remote)

Add to your Claude Desktop configuration file (claude_desktop_config.json):

{
  "mcpServers": {
    "coder": {
      "url": "https://coder.example.com/api/experimental/mcp/http"
    }
  }
}

Claude Desktop will automatically discover OAuth2 endpoints and prompt you to authenticate through your browser.

Manual Configuration

For MCP clients that don't support the registry or OAuth2 discovery, configure the server manually with a session token:

{
  "mcpServers": {
    "coder": {
      "url": "https://coder.example.com/api/experimental/mcp/http",
      "headers": {
        "Coder-Session-Token": "<your-session-token>"
      }
    }
  }
}

To create a session token:

Navigate to your Coder deployment
Go to Settings > Tokens
Create a new token
Add the token to your MCP client configuration

Authentication

The MCP server supports two authentication methods:

OAuth2 (Recommended for Interactive Clients)

MCP clients that support RFC 9728 (Protected Resource Metadata) can authenticate automatically using OAuth2. The server advertises its OAuth2 capabilities via the WWW-Authenticate header and /.well-known/oauth-protected-resource endpoint.

This enables a seamless "click-to-connect" experience where users authenticate through their browser without manually managing tokens.

Note

OAuth2 requires the oauth2 experiment to be enabled on your Coder deployment.

Session Token (For Programmatic Access)

For clients that don't support OAuth2 discovery, or for programmatic access, use a session token as shown in the Manual Configuration section.

Available Tools

The MCP server exposes tools across several areas:

Workspace management: list, inspect, create, and build workspaces
Template operations: list, inspect, create, and manage templates and versions
File operations: read, write, and edit files in a workspace
Workspace interaction: run commands, forward ports, list apps, and read logs
Task management: create, list, inspect, and control tasks
User and system: authenticated user details, tar uploads, and task reporting

The full, authoritative set of tools, including their names, descriptions, and arguments, is defined in Coder's toolsdk package. Refer to it for the current list, since the available tools can change between releases.

Troubleshooting

"Unauthorized" errors

Verify your session token is valid and not expired
Check that the MCP server experiment is enabled on your deployment
Ensure your user has appropriate permissions for the requested operations

Connection timeouts

Verify your Coder deployment URL is correct and accessible
Check network connectivity between your MCP client and the Coder server
Review Coder server logs for any errors

OAuth2 authentication not working

Ensure your Coder deployment has the oauth2 experiment enabled
Verify your MCP client supports RFC 9728 Protected Resource Metadata
Check that your browser can reach the Coder authorization endpoint