Anthropic Claude Code HERMES.md billing flaw was a technical defect in Anthropic's Claude Code product that bypassed flat-rate subscription plans to charge users direct API fees. In April 2026, a flaw triggered by the exact string "HERMES.md" in a user's git commit history routed subscribers directly to pay-as-you-go billing, charging one account over $200.[1]
HERMES.md billing switch
On April 25, 2026, a user reported that the exact string "HERMES.md" in their local git commit history caused Claude Code to route queries outside of their fixed-rate subscription plan.[1] The system bypassed the $200 per month Max plan and charged the user direct, pay-as-you-go API rates.[1] The user lost over $200 in extra charges while 86 percent of their prepaid plan capacity remained available.[1]
Anthropic's response
When the affected user contacted Anthropic support, the company refused to issue a refund for the $200 lost to the glitch, categorizing the overcharge as an un-refundable technical error.[2]
References
- ↑ 1.0 1.1 1.2 1.3 sasha-id (2026-04-25). "HERMES.md in git commit messages causes requests to route to extra usage billing instead of plan quota #53262". GitHub. Retrieved 2026-04-26.
- ↑ "PSA: The string 'HERMES.md' in your git commit history silently..." Reddit. 2026-04-26. Retrieved 2026-04-26.