GitHub MCP Server Policy

Sandbox the GitHub MCP server. Both REST and GraphQL live on api.github.com.

What it needs

Resource	Access	Details
Filesystem	Read + Write	Cache for API responses, output for generated files
Network	`api.github.com`	REST API + GraphQL (same hostname)
Env	`GITHUB_TOKEN`	GitHub personal access token

Complete Policy

command: ["node", "@modelcontextprotocol/server-github"]

filesystem:
  read:
    - "./cache"              # API response cache
  write:
    - "./output"             # Generated diffs, reports

network:
  allow:
    - "api.github.com"       # REST + GraphQL

env:
  allow:
    - "GITHUB_TOKEN"
    - "HOME"

limits:
  memory_mb: 256
  timeout_s: 300

How to run

# Step 1: Install the server
npm install -g @modelcontextprotocol/server-github

# Step 2: Set your token
export GITHUB_TOKEN="ghp_xxxxxxxxxxxx"

# Step 3: Run sandboxed
warden run --policy policy-github.yaml

Tips

Grant HOME if the server needs to read git config or .netrc
Never put GITHUB_TOKEN in the policy, give only the name; the value comes from the shell
Both GraphQL and REST are on api.github.com, so one entry is enough
Increase timeout_s for long-running PR reviews

Troubleshooting

Error	Fix
`permission denied` on network	Check that `api.github.com` is in `network.allow`
Token not found	Export `GITHUB_TOKEN` in the shell; the policy contains only the name
Rate limiting	Grant write access to the `cache` directory

Resources

← Google Drive MCP Server Policy Notion MCP Server Policy →