A GitHub Action wrapper for the GitHub Copilot CLI that enables AI-powered automation in your workflow files.

Add the copilot-requests: write permission to your workflow. The default GITHUB_TOKEN now handles Copilot authentication — no PAT required.

Add the following workflow to your .github/workflows folder:

name: 'Copilot Automation'
on: [pull_request]

permissions:
  copilot-requests: write
  pull-requests: write

jobs:
  copilot:
    runs-on: ubuntu-latest
    steps:
      - name: 'Checkout Repository'
        uses: actions/checkout@v5

      - name: 'Run Copilot CLI'
        uses: austenstone/copilot-cli@v3
        with:
          prompt: |
            Review this pull request for:
            1. Code quality and best practices
            2. Security vulnerabilities
            3. Performance implications
            4. Documentation completeness

          prompt: 'What time is it?'
          mcp-config: |
            {
              "mcpServers": {
                "time": {
                  "type": "local",
                  "command": "uvx",
                  "args": ["mcp-server-time", "--local-timezone", "America/New_York"],
                  "tools": ["*"]
                }
              }
            }

The action supports Model Context Protocol (MCP) servers for extending Copilot's capabilities. Configure MCP servers using JSON format with an mcpServers object where each key is the server name and the value contains its configuration.

1. "Copilot token required" / Permission Denied

   • Ensure your workflow has copilot-requests: write permission
   • Your org must enable the "Allow use of Copilot CLI billed to the organization" policy
   • If using a legacy PAT, ensure it has the "Copilot Requests" permission

2. Copilot starts but permission denied on repo operations

   • Add appropriate permissions (e.g., contents: write, pull-requests: write)
   • Check Settings > Actions > General > Workflow permissions

3. Tool Access Denied

   • Check your allowed-tools and denied-tools configuration
   • If allow-all-tools: false, you must explicitly allow needed tools

4. MCP Server Connection Issues

   • Verify MCP server URLs are accessible from GitHub-hosted runners
   • Check authentication headers and tokens
   • Ensure type is set correctly (local, http, or sse)

5. Session Resume Not Working

   • Session data is stored in logs; ensure upload-artifact: true
   • Use resume-session: latest to continue the most recent session

6. Large Output Truncation

   • Set log-level: error or log-level: warning to reduce verbosity
   • Break complex prompts into smaller, focused tasks

• GitHub Copilot CLI Documentation
• Model Context Protocol (MCP)
• MCP Server Configuration Docs
• Search for workflow examples