Claude Code v2.1.42

Claude Code v2.1.42 was released on .

Summary

- Improved startup performance by deferring Zod schema construction - Improved prompt cache hit rates by moving date out of system prompt - Added one-time Opus 4.6 effort callout for eligible users...

Release Context

  • This was the 35th Claude Code release of 2026 tracked by Havoptic.
  • It shipped 1 day after Claude Code v2.1.41 (February 13, 2026).

Shipped around the same time

Within 3 days of this release, other AI coding tools also shipped:

Compare Claude Code: vs OpenAI Codex CLI · vs Cursor · vs Gemini CLI · vs Kiro CLI · vs GitHub Copilot CLI · vs Devin Desktop · vs Antigravity CLI

Release Notes

View original release

Other Recent Claude Code Releases

All Claude Code releases · All AI coding tool releases on Havoptic