Anthropic API 529 Overloaded Error

HTTP 529 overloaded_error means Anthropic capacity for that model is saturated. Your key and payload are fine.

Step 1 — Retry with exponential backoff

Delays of 1s, 2s, 4s, 8s with random jitter, capped at five attempts. Never retry in a tight loop.

Step 2 — Add a fallback model

Overload is usually model-specific. Route to a smaller Claude model when the primary returns 529.

Step 3 — Reduce per-request size

Trim system prompts, use prompt caching, and split very large contexts.

Step 4 — Queue batch work

Run bulk jobs off-peak behind a concurrency-limited queue.

Step 5 — Alert on sustained 529s

If more than a few percent of requests fail for over fifteen minutes, treat it as an incident and check Anthropic status.