Published onJuly 31, 2026Improving Token Efficiency for GitHub Copilot in VS CodeAI-AgentsGitHub-CopilotVS-CodeToken-OptimizationPrompt-CachingWebSocketsArchitectureInside VS Code's harness-level engineering: how extended prompt caching, embedding-guided tool search, and WebSockets cut agent tokens by up to 28% and idle latency by 19%.