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API Error Code Reference Builder
Build and maintain a searchable reference table of your API's custom error codes — code, HTTP status, message, and cause — then export it as Markdown or JSON to drop into your docs.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
| Code | HTTP status | Message | Cause |
|---|
Example shown — edit rows or add your own error codes.
How it works
- Start from the sample rows or add your own error codes with the "+ Add error code" button.
- Fill in each code's HTTP status, human-readable message, and the underlying cause.
- Search to find a code quickly, then export the whole table as Markdown or JSON for your documentation.
FAQ
Why maintain a custom error code table separately from HTTP status codes?
HTTP status codes alone are too coarse to tell a 400 from any other 400 — a custom code like AUTH_001 lets your API consumers programmatically distinguish "expired token" from "malformed request body" without parsing free-text messages.
Can I export this to drop into my API docs?
Yes — export as Markdown for a table you can paste directly into a docs page, or as JSON if you want to feed the reference into your own tooling or a docs generator.
Is my error code data saved anywhere?
No — everything lives only in this page's memory while you have it open. Export to Markdown or JSON before closing the tab if you want to keep your work, since nothing is uploaded or persisted.
Reference builder vs. a full API docs platform
| Feature | This tool | Full API docs platform |
|---|---|---|
| Fast to sketch out a reference table | ✓ | ✗ |
| Hosted, versioned, linked to live OpenAPI specs | ✗ | ✓ |
Great for drafting the table quickly, then pasting into whatever docs platform your team already uses.