• Explore repository structure and understand current state
• Understand MCP completion protocol requirements
• Identify resource templates that need completion support
• Verify build and test setup works
• Add completion capability to server configuration
• Implement CompletionHandlerFunc type and registration
• Create repository_completions.go with GitHub API completion logic
• Add completion handler to server registration
• Write tests for completion functionality
• Create completion-aware stdio server wrapper
• Implement custom in-process transport for GitHubMCPServer
• Test end-to-end completion behavior with working MCP client
• Update library dependencies to latest version

Successfully implemented full completion support for GitHub MCP Server!

Core Completion Logic:

• CompletionHandlerFunc type and registration in GitHubMCPServer
• Comprehensive RepositoryCompletionHandler that provides contextual completions for:
  • Repository owners/organizations (via GitHub search)
  • Repository names (via GitHub search with owner context)
  • Branch names (via GitHub API for specific repos)
  • Commit SHAs (via GitHub API for specific repos)
  • Tag names (via GitHub API for specific repos)
  • Pull request numbers (via GitHub API for specific repos)
  • File paths (via GitHub API directory listings)

Custom MCP Server & Transport:

• Extended GitHubMCPServer that wraps base MCPServer and overrides HandleMessage
• Custom completion handling that intercepts completion/complete requests
• GitHubInProcessTransport that routes requests through the custom server
• Proper JSON-RPC error and response handling
• Falls back to base server for all non-completion requests

Working Integration:

• ✅ End-to-end completion tests passing using custom in-process client
• ✅ Proper error handling for invalid requests and GitHub API failures
• ✅ Empty completion results for non-repo URIs and unsupported arguments
• ✅ Full test coverage including unit and integration tests
• ✅ All existing tests continue to pass

Client Usage:

• Use NewInProcessClientWithGitHubServer() for testing with completion support
• Use custom stdio server wrapper for command-line completion support
• Maintains backward compatibility with existing toolsets and resources

The completion feature now works end-to-end and provides intelligent GitHub resource completions based on context!

Fixes #422.

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.