When HERMES.md appears in a commit message, it gets routed into the extra usage billing path

A bug was confirmed where, if the string HERMES.md appeared in a commit message, Claude Code requests were incorrectly routed into the extra usage billing path instead of the Max plan quota. This had nothing to do with whether the file actually existed on disk—the content of the commit message itself was the trigger.

The issue was reproducible on Claude Code v2.1.119, macOS Apple Silicon, and the Max 20x plan ($200/month). The same behavior was observed on both claude-opus-4-6[1m] and claude-opus-4-7: running git commit -m 'add HERMES.md' followed by claude -p 'say hello' --model 'claude-opus-4-6[1m]' produced API Error: 400 You're out of extra usage.... Changing the message to add hermes.md resulted in a normal response.

The impact showed up directly in billing and availability.

• Even though weekly usage was only around 13%, $200.98 worth of extra usage credit was consumed.
• The dashboard showed 86%+ capacity remaining, meaning the displayed state didn't match the actual routing.
• Once extra usage ran out, multiple projects became unusable.

Anthropic attributed the cause to an overly aggressive anti-abuse system and stated that it has already been fixed. The issue was subsequently closed as completed, and Anthropic announced it would issue full refunds to affected users along with additional usage credits equivalent to their monthly subscription fee.