API Error: "Output blocked by content filtering policy" recurring on benign output

Recurring API Error: Output blocked by content filtering policy during normal Claude Code use.

Behavior: The error blocks response output. It triggers on benign content — writing ordinary code, JSON, and config files, and at times on plain conversational text with no tool calls. Completed tool calls persist; only the reply output is blocked.

Pattern: Intermittent. Starting a fresh session does not help — fresh sessions often hit it on the first substantial output. Retrying ("Try again") sometimes succeeds, making longer work sessions very slow.

Started: ~2026-05-16. The status page showed a resolved incident that day ("Elevated error rates on requests to multiple models"), but the filtering errors continued after it was marked resolved.

Environment: Claude Code CLI, macOS (Darwin 25.4.0), model Opus 4.7 (1M context).

Impact: Multi-step build tasks are not completable in one sitting — every output is at risk of being blocked.