Modelpeers

Claude Opus 4.6 changelog

Every change to Claude Opus 4.6 that Modelpeers has recorded, newest first, each with the source it came from. The record starts Apr 12, 2026.

All (3)Breaking changes (1)Prices/limits (1)Quality (1)

April 2026

Claude Code character

Claude Code and Opus 4.6

2 products from Anthropic

Limits change

Max 5x users report quota exhausted in 1.5 hours, Claude Code team points to 1M-context cache misses

A GitHub issue reported a Max 5x quota exhausted within 1.5 hours of moderate use on Opus 4.6 with 1M context. Claude Code's Boris Cherny replied that stale sessions over an hour old cause full cache misses with the 1M window and that Anthropic was investigating a 400k default. The thread drew 759 points and 660 comments.

Who is affected:
Claude Max subscribers using 1M-context sessions in Claude Code.
Action needed:
Run /clear before resuming sessions idle for over an hour, or set CLAUDE_CODE_AUTO_COMPACT_WINDOW=400000.

1 incident is listed on the Claude Opus 4.6 page. Get this changelog in a feed reader with the RSS feed.