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| 1 | +# Install GitHub MCP Server in OpenCode |
| 2 | + |
| 3 | +[OpenCode](https://opencode.ai) 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](./README.md). |
| 4 | + |
| 5 | +## Prerequisites |
| 6 | + |
| 7 | +1. OpenCode installed (`brew install sst/tap/opencode` or see [OpenCode install docs](https://opencode.ai/docs/)) |
| 8 | +2. [GitHub Personal Access Token](https://github.com/settings/personal-access-tokens/new) with appropriate scopes |
| 9 | +3. For local installation: [Docker](https://www.docker.com/) installed and running |
| 10 | + |
| 11 | +> [!IMPORTANT] |
| 12 | +> 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](../server-configuration.md) and the [main README's toolsets section](../../README.md#available-toolsets). |
| 13 | +
|
| 14 | +## Remote Server (Recommended) |
| 15 | + |
| 16 | +Uses GitHub's hosted server at `https://api.githubcopilot.com/mcp/`. Edit your [OpenCode config](https://opencode.ai/docs/config/) (typically `~/.config/opencode/opencode.json`, or `opencode.json` in your project root) and add the following under `mcp`: |
| 17 | + |
| 18 | +```json |
| 19 | +{ |
| 20 | + "$schema": "https://opencode.ai/config.json", |
| 21 | + "mcp": { |
| 22 | + "github": { |
| 23 | + "type": "remote", |
| 24 | + "url": "https://api.githubcopilot.com/mcp/", |
| 25 | + "enabled": true, |
| 26 | + "oauth": false, |
| 27 | + "headers": { |
| 28 | + "Authorization": "Bearer YOUR_GITHUB_PAT" |
| 29 | + } |
| 30 | + } |
| 31 | + } |
| 32 | +} |
| 33 | +``` |
| 34 | + |
| 35 | +Replace `YOUR_GITHUB_PAT` with your [GitHub Personal Access Token](https://github.com/settings/tokens). The `oauth: false` setting disables OpenCode's automatic OAuth discovery and tells it to use the PAT in `Authorization` instead — without this, OpenCode may try the OAuth flow first. |
| 36 | + |
| 37 | +### Using an environment variable for the PAT |
| 38 | + |
| 39 | +OpenCode supports environment-variable interpolation in config values via `{env:VAR_NAME}`. To avoid putting your PAT directly in `opencode.json`: |
| 40 | + |
| 41 | +```json |
| 42 | +{ |
| 43 | + "$schema": "https://opencode.ai/config.json", |
| 44 | + "mcp": { |
| 45 | + "github": { |
| 46 | + "type": "remote", |
| 47 | + "url": "https://api.githubcopilot.com/mcp/", |
| 48 | + "enabled": true, |
| 49 | + "oauth": false, |
| 50 | + "headers": { |
| 51 | + "Authorization": "Bearer {env:GITHUB_PERSONAL_ACCESS_TOKEN}" |
| 52 | + } |
| 53 | + } |
| 54 | + } |
| 55 | +} |
| 56 | +``` |
| 57 | + |
| 58 | +Set `GITHUB_PERSONAL_ACCESS_TOKEN` in your shell environment before starting OpenCode. |
| 59 | + |
| 60 | +## Local Server (Docker) |
| 61 | + |
| 62 | +The local GitHub MCP server runs via Docker and requires Docker Desktop (or another Docker runtime) to be installed and running. |
| 63 | + |
| 64 | +```json |
| 65 | +{ |
| 66 | + "$schema": "https://opencode.ai/config.json", |
| 67 | + "mcp": { |
| 68 | + "github": { |
| 69 | + "type": "local", |
| 70 | + "command": [ |
| 71 | + "docker", "run", "-i", "--rm", |
| 72 | + "-e", "GITHUB_PERSONAL_ACCESS_TOKEN", |
| 73 | + "ghcr.io/github/github-mcp-server" |
| 74 | + ], |
| 75 | + "enabled": true, |
| 76 | + "environment": { |
| 77 | + "GITHUB_PERSONAL_ACCESS_TOKEN": "YOUR_GITHUB_PAT" |
| 78 | + } |
| 79 | + } |
| 80 | + } |
| 81 | +} |
| 82 | +``` |
| 83 | + |
| 84 | +> [!IMPORTANT] |
| 85 | +> 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. |
| 86 | +
|
| 87 | +## Verify Installation |
| 88 | + |
| 89 | +1. Restart OpenCode (or start a new session). |
| 90 | +2. Check that the server is discovered: |
| 91 | + ```sh |
| 92 | + opencode mcp list |
| 93 | + ``` |
| 94 | +3. Try a prompt that references the server by name to bias the model toward its tools: |
| 95 | + ``` |
| 96 | + Use the github tool to list my recently merged pull requests. |
| 97 | + ``` |
| 98 | + |
| 99 | +## Managing the Server |
| 100 | + |
| 101 | +OpenCode exposes a few useful subcommands for MCP servers: |
| 102 | + |
| 103 | +| Command | Purpose | |
| 104 | +| --- | --- | |
| 105 | +| `opencode mcp list` | List configured MCP servers and their auth/connection status. | |
| 106 | +| `opencode mcp debug github` | Show auth status, test HTTP connectivity, and walk through OAuth discovery for the `github` server. | |
| 107 | +| `opencode mcp auth github` | Trigger an OAuth flow manually (only relevant if `oauth` is not set to `false`). | |
| 108 | +| `opencode mcp logout github` | Clear stored OAuth tokens for the server. | |
| 109 | + |
| 110 | +## Disabling Tools Per-Agent |
| 111 | + |
| 112 | +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: |
| 113 | + |
| 114 | +```json |
| 115 | +{ |
| 116 | + "$schema": "https://opencode.ai/config.json", |
| 117 | + "mcp": { |
| 118 | + "github": { |
| 119 | + "type": "remote", |
| 120 | + "url": "https://api.githubcopilot.com/mcp/", |
| 121 | + "enabled": true, |
| 122 | + "oauth": false, |
| 123 | + "headers": { "Authorization": "Bearer {env:GITHUB_PERSONAL_ACCESS_TOKEN}" } |
| 124 | + } |
| 125 | + }, |
| 126 | + "tools": { |
| 127 | + "github_*": false |
| 128 | + }, |
| 129 | + "agent": { |
| 130 | + "github-helper": { |
| 131 | + "tools": { "github_*": true } |
| 132 | + } |
| 133 | + } |
| 134 | +} |
| 135 | +``` |
| 136 | + |
| 137 | +This pattern is recommended by the [OpenCode MCP docs](https://opencode.ai/docs/mcp-servers/) for servers with many tools. |
| 138 | + |
| 139 | +## Troubleshooting |
| 140 | + |
| 141 | +- **`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. |
| 142 | +- **Server marked failed in `opencode mcp list`**: run `opencode mcp debug github` to see the exact connectivity and auth diagnostics. |
| 143 | +- **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. |
| 144 | +- **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. |
| 145 | +- **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`). |
| 146 | + |
| 147 | +## Important Notes |
| 148 | + |
| 149 | +- **Configuration key**: OpenCode uses `mcp` (not `mcpServers` or `context_servers`). |
| 150 | +- **Type discriminator**: every entry must include `"type": "local"` or `"type": "remote"`. |
| 151 | +- **Command shape**: `command` is a single array combining the executable and its arguments. |
| 152 | +- **Environment variable key**: `environment` (not `env`). |
| 153 | +- **OAuth**: enabled by default for remote servers. Set `"oauth": false` when using PAT-in-`Authorization`, otherwise OpenCode may try OAuth first. |
| 154 | +- **Env interpolation**: use `{env:VAR_NAME}` in string values to read from the shell environment instead of hard-coding secrets. |
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