API Errors

529 overloads, rate limits, authentication

Anthropic API 529 Error: How to Fix It

A 529 means Anthropic's API is overloaded. Here is how to retry correctly and design around it.

Claude API Rate Limit Exceeded: Fixes

429 errors from the Anthropic API explained: request, token and daily limits, and how to stay under them.

Anthropic API Key Authentication Failing

401 invalid_api_key or permission errors from the Claude API — the full diagnostic checklist.