Common errors hit by AI agents.
When an agent loop fails, the first signal is usually an HTTP status from an upstream provider. This is the index — what the error means, why agents trigger it more often than humans, and how to fix it.
Claude 529 — Overloaded
Anthropic returned overloaded; what causes it in agent loops and how to back off correctly.
Coming soon
OpenAI 429 — Rate limit exceeded
TPM vs RPM, why agents hit it faster, and the right retry strategy.
Coming soon
OpenAI 400 — Context length exceeded
When tool histories blow past the model's context window.
Coming soon
MCP — Transport closed
What it means when your MCP client loses the stream mid-call.
Coming soon
Anthropic 401 — Invalid API key
Common causes, including key rotation drift and proxy header stripping.
Coming soon