Install GitHub MCP Server in OpenCode

OpenCode is a terminal-based AI coding agent that exposes MCP servers under the mcp key in opencode.json (or opencode.jsonc). For general setup information (prerequisites, Docker installation, security best practices), see the Installation Guides README.

Prerequisites

1. OpenCode installed (brew install sst/tap/opencode or see OpenCode install docs)
2. GitHub Personal Access Token with appropriate scopes
3. For local installation: Docker installed and running

[!IMPORTANT] The OpenCode docs note that the GitHub MCP server can add a lot of tokens to your context. Consider limiting toolsets — for example, by setting X-MCP-Toolsets on the remote server or --toolsets on the local server — to keep prompts within your model's context window. See the Server Configuration Guide and the main README's toolsets section.

Remote Server (Recommended)

Uses GitHub's hosted server at https://api.githubcopilot.com/mcp/. Edit your OpenCode config (typically ~/.config/opencode/opencode.json, or opencode.json in your project root) and add the following under mcp:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "github": {
      "type": "remote",
      "url": "https://api.githubcopilot.com/mcp/",
      "enabled": true,
      "oauth": false,
      "headers": {
        "Authorization": "Bearer YOUR_GITHUB_PAT"
      }
    }
  }
}

Replace YOUR_GITHUB_PAT with your GitHub Personal Access Token. The oauth: false setting disables OpenCode's automatic OAuth discovery and tells it to use the PAT in Authorization instead — without this, OpenCode may try the OAuth flow first.

Using an environment variable for the PAT

OpenCode supports environment-variable interpolation in config values via {env:VAR_NAME}. To avoid putting your PAT directly in opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "github": {
      "type": "remote",
      "url": "https://api.githubcopilot.com/mcp/",
      "enabled": true,
      "oauth": false,
      "headers": {
        "Authorization": "Bearer {env:GITHUB_PERSONAL_ACCESS_TOKEN}"
      }
    }
  }
}

Set GITHUB_PERSONAL_ACCESS_TOKEN in your shell environment before starting OpenCode.

Local Server (Docker)

The local GitHub MCP server runs via Docker and requires Docker Desktop (or another Docker runtime) to be installed and running.

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "github": {
      "type": "local",
      "command": [
        "docker", "run", "-i", "--rm",
        "-e", "GITHUB_PERSONAL_ACCESS_TOKEN",
        "ghcr.io/github/github-mcp-server"
      ],
      "enabled": true,
      "environment": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "YOUR_GITHUB_PAT"
      }
    }
  }
}

[!IMPORTANT] OpenCode expects command as a single array combining the executable and its arguments (e.g. ["docker", "run", "-i", ...]), and the env-var key is environment (not env). This differs from hosts like Zed and Cursor.

Verify Installation

1. Restart OpenCode (or start a new session).
2. Check that the server is discovered:
   shCopy

   opencode mcp list
   

3. Try a prompt that references the server by name to bias the model toward its tools:
   Copy

   Use the github tool to list my recently merged pull requests.
   

Managing the Server

OpenCode exposes a few useful subcommands for MCP servers:

Disabling Tools Per-Agent

Because the GitHub MCP server can register a large number of tools, you may want to disable them globally and re-enable them only for specific agents. OpenCode uses the <server-name>_* glob pattern to match all tools from a server:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "github": {
      "type": "remote",
      "url": "https://api.githubcopilot.com/mcp/",
      "enabled": true,
      "oauth": false,
      "headers": { "Authorization": "Bearer {env:GITHUB_PERSONAL_ACCESS_TOKEN}" }
    }
  },
  "tools": {
    "github_*": false
  },
  "agent": {
    "github-helper": {
      "tools": { "github_*": true }
    }
  }
}

This pattern is recommended by the OpenCode MCP docs for servers with many tools.

Troubleshooting

• 401 Unauthorized from the remote server: confirm your PAT is valid and not expired. If you set oauth: false, OpenCode will not attempt an OAuth fallback — the Authorization header must be correct.
• Server marked failed in opencode mcp list: run opencode mcp debug github to see the exact connectivity and auth diagnostics.
• Tools missing from prompts: check that enabled: true is set on the server and that you have not disabled github_* in your tools block without re-enabling it for the current agent.
• Context window exceeded: the GitHub MCP server can register many tools. Use server-side toolset filtering (X-MCP-Toolsets header) to register only the toolsets you need.
• Docker errors on the local server: ensure Docker Desktop is running and the ghcr.io/github/github-mcp-server image has been pulled (docker pull ghcr.io/github/github-mcp-server).

Important Notes

• Configuration key: OpenCode uses mcp (not mcpServers or context_servers).
• Type discriminator: every entry must include "type": "local" or "type": "remote".
• Command shape: command is a single array combining the executable and its arguments.
• Environment variable key: environment (not env).
• OAuth: enabled by default for remote servers. Set "oauth": false when using PAT-in-Authorization, otherwise OpenCode may try OAuth first.
• Env interpolation: use {env:VAR_NAME} in string values to read from the shell environment instead of hard-coding secrets.