failproxy

Overview ¶

Command failproxy is a fault-injection stand-in for the Anthropic API, used by interface probes to induce API errors inside a Claude Code turn (point ANTHROPIC_BASE_URL at it — honoured under subscription OAuth, spikes/FINDINGS.md §3).

Modes:

• default: every request gets -status with an Anthropic-shaped error body. Zero real tokens.
• -upstream https://api.anthropic.com: reverse-proxy to the real API, but fail the Nth and later /v1/messages requests (-fail-after N). This is how a *mid-turn* failure is induced: the first request succeeds so the turn starts, a later one dies.

It never reads, logs, or stores request headers — the Authorization header on these requests carries a live OAuth token. Only method, path and the injected status are logged.