Claude Code Hidden Problem Analysis

Claude Code Hidden Problem Analysis is a GitHub repository by ArkNill that documents measured client-side bugs and server-side quota behavior in Anthropic's Claude Code. It combines proxy-captured request data, JSONL session analysis, rate limit header analysis and CHANGELOG cross-references through v2.1.140. The README states it is based on community research and personal measurement and is not endorsed by Anthropic.

What It Is

The repository is a research and documentation project rather than a software tool. It tracks 11 confirmed client-side bugs (B1-B5, B8, B8a, B9, B10, B11, B2a) and 3 preliminary findings. It records which bugs are fixed, possibly fixed or unfixed across Claude Code releases. The author reports the analysis started when a Max 20 plan hit 100% usage in about 70 minutes, and later grew with community contributions.

Evidence and Method

The author used a transparent monitoring proxy (cc-relay) to capture per-request data and rate limit headers. The README reports 45,884 requests across 320 sessions between April 1 and 22. These were cross-checked against independent community datasets and against Anthropic's April 23 postmortem. Chapters cover the dual 5-hour and 7-day quota windows, thinking-token accounting, microcompact and tool-result budget behavior, and per-environment cache ratios.

Opus 4.7 Advisory

A dedicated advisory recommends staying on v2.1.109 with Opus 4.6. It cites a 2.4x averaged five-hour quota burn on Opus 4.7, model pin bypass, cache metering anomalies and an autocompact threshold of about 195K tokens. It also describes sycophancy and narrow-scope behavior patterns, rated by evidence strength.

Practical Guidance

A quick-fix guide covers version pinning with DISABLE_AUTOUPDATER=1, avoiding --resume and --continue, starting fresh sessions periodically, and checking whether the npm or standalone build is in use. Companion documents provide a usage guide, an advanced guide on hooks, subagents and monitoring, an issue index and a Korean translation.