One user burned through $200.98 of “extra usage” on Claude Code while 86% of their $200/month Max plan quota was sitting untouched. The cause: a git commit message containing the exact string HERMES.md. Claude Code includes recent git history in its system prompt. A server-side content filter was matching that specific string — case-sensitive, with the .md extension; hermes.md and AGENTS.md both worked fine — and silently rerouting all API requests from plan quota to a separate extra billing pool. No error until the extra usage ran out, at which point everything fails with a 400 billing error. Anthropic initially refused to refund the charge: “we are unable to issue compensation for degraded service or technical errors.” That response attracted more negative votes than the bug report itself. The patch and refunds came after the issue went viral on HN. The fix addressed this specific trigger. What it didn’t address: why API billing is allowed to depend on the content of developer commit messages at all, and nobody outside Anthropic knows what other strings trigger the same routing behavior. If you’re on a Max plan and hit unexplained billing 400s, check your recent commit history before assuming the plan ran out. Source: https://github.com/anthropics/claude-code/issues/53262 submitted by /u/jimmytoan
Originally posted by u/jimmytoan on r/ClaudeCode