| name | anth-common-errors |
| description | Diagnose and fix Anthropic Claude API errors by HTTP status code.
Use when encountering API errors, debugging failed requests,
or troubleshooting authentication, rate limiting, or input validation issues.
Trigger with phrases like "anthropic error", "claude api error",
"fix anthropic 429", "claude not working", "debug claude api".
|
| allowed-tools | Read, Grep, Bash(curl:*) |
| version | 1.6.0 |
| license | MIT |
| author | Jeremy Longshore <jeremy@intentsolutions.io> |
| tags | ["saas","ai","anthropic"] |
| compatibility | Designed for Claude Code |
Anthropic Common Errors
Overview
Quick reference for all Claude API error types with exact HTTP codes, error bodies, and fixes. The API returns errors as JSON: {"type": "error", "error": {"type": "...", "message": "..."}}.
Error Reference
400 — invalid_request_error
{"type": "error", "error": {"type": "invalid_request_error", "message": "messages: roles must alternate between \"user\" and \"assistant\""}}
Common causes and fixes:
| Message Pattern | Cause | Fix |
|---|
messages: roles must alternate | Consecutive same-role messages | Merge adjacent user/assistant messages |
max_tokens: must be >= 1 | Missing or zero max_tokens | Always set max_tokens (required param) |
model: invalid model id | Typo in model name | Use exact ID: claude-sonnet-4-20250514 |
messages.0.content: empty | Empty message content | Ensure content is non-empty string or array |
tool_result: tool_use_id not found | Mismatched tool ID | Copy id from the tool_use block exactly |
401 — authentication_error
echo $ANTHROPIC_API_KEY | -c 15
curl -s https://api.anthropic.com/v1/messages \
-H \
-H \
-H \
-d
