copilot

Copilot Chat v0.42: Context Compaction & Session Fixes

Copilot Chat v0.42 fixes context compaction issues, adds session checkpoints and discard changes, and hardens Claude integration with proper MCP tool schema support.

TL;DR

Fixed premature context compaction by decoupling token ratios and raising thresholds
Sessions now support checkpoints, discard changes, and improved workspace tracking
Claude integration hardened with proper MCP tool schema preservation and auth fixes

Fixed

Premature compaction — context was being compacted too early; decoupled ratio from tool tokens and raised thresholds to keep more conversation history
Tool call image handling — fixed continuation logic for tool call images to prevent processing errors
Document validation triggers — PromptsServiceImpl no longer uses openTextDocument, avoiding unnecessary validation overhead
Race condition in code search — fixed possible race where external ingest wasn't seeing code search repos
Chat session command conditions — updated command condition logic for proper session state handling

New

Session checkpoints — all sessions can now create checkpoints to save progress
Discard changes action — sessions include confirmation dialog and action to discard unsaved changes
File watcher for workspace tracking — sessions now use file watcher instead of git extension API for better reliability
Dynamic prompt variables — support for variables that change based on context
OTel metrics for edits — added observability for edit acceptance and code survival telemetry
Enhanced GitHub auth — improved session handling with detailed prompts for authentication
Claude MCP support — proper schema preservation for Anthropic API and Bearer token authentication
Rate limit handling — process rate limits and quota from WebSocket responses