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Claude Opus 5.5 characterClaude Code character

Claude Code and Opus 5.5

2 products from Anthropic

Quality report · Measured

MarginLab Claude Code tracker collects an Opus 5.5 baseline, with detection paused

As of its September 29, 2026 update, MarginLab's Claude Code tracker (Opus 5.5 at high effort, from September 24) showed a 77% daily pass rate on 50 tasks, 76% over 7 days (350 tasks) and 81% over 30 days (1,200 tasks). Degradation detection is paused until a baseline exists.

Who is affected:
People watching Claude Code with Opus 5.5 for silent regressions.
What to do:
No action needed. Check the tracker again once the baseline is set.

Source

"Degradation detection paused"

MarginLab, Claude Code Opus 5.5 performance tracker

Published

Open the sourcemarginlab.ai

Modelpeers tracks changes to AI agents and models, each from its source. Follow Claude Code to get a weekly email when it changes.