OpenAI & Claude API Errors — Fix Guides Index (2026)
Index of APIMaster fix guides for common OpenAI, Claude, and ChatGPT API errors: 400 content blocked, invalid API key, 429 rate limits, 529 overloaded, and unsupported location.
Published 2026-06-29
Hit an OpenAI, Claude, or ChatGPT API error and searched the exact message on Google? This index links to one focused fix guide per error — moderation blocks, auth failures, rate limits, server overload, and region restrictions — plus when to use APIMaster as an OpenAI-compatible gateway with multi-channel fallback.
Fix Guides by Error Type
Authentication (401)
How to Fix Invalid API Key (OpenAI / Claude)
Symptoms: invalid_api_key, Incorrect API key provided, authentication_error.
→ Test instantly: API Key Tester (free, no signup)
Content moderation (400)
Fix "api error 400 messages text content blocked"
Symptoms: text content blocked, content_filter, moderation before inference.
Rate limits (429)
Fix OpenAI Rate Limit Exceeded
Symptoms: rate_limit_exceeded, RPM/TPM caps, retry-after headers.
Server overload (529)
Fix Claude / Anthropic 529 Overloaded
Symptoms: overloaded_error, claude overloaded, temporary capacity.
Region / product availability
Fix ChatGPT Unsupported Location
Symptoms: unsupported location, chatgpt 报错 unsupported, country not available.
Quick Decision Table
| HTTP | Typical code / message | Start here |
|---|---|---|
| 401 | invalid api key | Invalid API key guide |
| 400 | content blocked | 400 content blocked |
| 429 | rate_limit_exceeded | Rate limit guide |
| 529 | overloaded_error | 529 overloaded guide |
| — | unsupported location | Unsupported location |
When to Use APIMaster
- Invalid or flaky relay keys → Key Tester, then get a key from $1
- 429 / 529 on a single vendor → multi-channel routing at
https://apimaster.ai/v1 - Region or billing friction with OpenAI → OpenAI-compatible gateway (see Cursor setup)
- Suspect fake models on cheap APIs → Model Tester
Browse APIMaster marketplace →
FAQ
Should I read one big article or these separate pages? Each page targets one exact search query (how users actually Google errors). Use this index to jump to the right guide.
Are these errors only for official OpenAI/Anthropic? No — third-party relays often forward the same error strings. Fix steps cover both official APIs and OpenAI-compatible gateways.
Do you add more error guides? Yes — we expand this series as new high-volume error queries appear. Bookmark this index.