Claude: API Rate Limit Error (429)

Anthropic's API enforces both RPM (requests per minute) and TPM (tokens per minute) limits that scale with the API usage tier. The rate_limit_error type is distinct from overloaded_error — rate_limit_error is per-user and per-key, meaning the account has exceeded its own allocated limits. Anthropic's rate limits vary significantly by tier: Tier 1 has very low limits while Tier 4 and above support enterprise-scale throughput.