Troubleshooting · Claude Code

Claude Code API Error 529 Overloaded — What It Means

Claude Code prints API Error: 529 Overloaded when upstream capacity is saturated. Why it is not your request's fault, why it clusters, and what actually helps.

What you see

API Error: 529 {"type":"error","error":{"type":"overloaded_error","message":"Overloaded"}}

Why it happens

  • Upstream capacity is temporarily saturated. A 529 describes the service at that moment, not your request — nothing in your payload caused it.
  • It clusters during incidents and peak hours: the same request typically succeeds minutes later with no change on your side.

How to fix it

  • Let Claude Code retry — it backs off automatically. If a run keeps dying, wait a few minutes rather than hammering the same minute.
  • For long unattended runs, prefer smaller models for mechanical steps: they are generally less contended, so the run survives capacity dips.
  • If 529s persist for a long stretch, check the provider's status page before changing anything in your setup — your configuration is almost never the cause.

Related searches

  • claude code overloaded error
  • claude code 529 keeps happening

FAQ

Is a 529 different from a 429?+
Yes. A 429 is your own throughput ceiling; a 529 is upstream capacity. Backoff helps both, but only a 429 responds to reducing your own usage.
Did my prompt cause the 529?+
No. Overloaded is a service-side condition. The identical request usually succeeds once capacity recovers.
Should I switch models when I see 529s?+
For latency-sensitive work, temporarily using a smaller model helps because it is less contended. For everything else, waiting is enough.

All Claude Code errors · Claude API error codes · Setup guide

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