v2.1.156

Source: Anthropic Claude Code Date: 2026-05-29 URL: https://github.com/anthropics/claude-code/releases/tag/v2.1.156

Summary

One-line hotfix released overnight (May 29, 01:42 UTC): fixes an issue where Opus 4.8 thinking blocks were modified, leading to API errors. v2.1.155 was skipped (build-number gap, same pattern as v2.1.151). Follows v2.1.154 (May 28), the Opus 4.8 launch release that also shipped dynamic workflows GA.

Implications

A regression that only surfaces once a brand-new model is in heavy use within hours of launch — evidence Opus 4.8 adoption was immediate. Feeds the Anthropic distribution machine thread (Opus 4.8 launch arc) and the orchestration thread (the model that powers dynamic workflows). The same-day overnight turnaround is consistent with the background-agent reliability cadence Claude Code has held for weeks.