Error codes

All error responses from the TheNotificationApp API follow the same structure:

{
  "success": false,
  "error": "Error message here"
}

HTTP status codes

Status	Meaning
200	Success — notification sent
400	Bad request — invalid or missing fields
401	Unauthorized — missing or invalid API key
429	Too many requests — rate limit exceeded
500	Internal server error

400 errors — validation

Error message	Cause	Fix
Title and body are required	title or body missing from the request body	Include both fields in your JSON payload
Title and body must be strings	title or body is not a string (e.g. a number or null)	Ensure both values are strings
Link must be a string	link field is not a string	Pass a string URL or omit the field
Image must be a string	image field is not a string	Pass a string URL or omit the field
No devices registered for this application	The app key is valid but no device is linked to it	Open the iOS app and ensure you're signed in with the correct account

401 errors — authentication

Error message	Cause	Fix
Missing app_key header	The app_key header was not included	Add the app_key header to every request
Invalid app_key	The API key doesn't match any application	Check for typos, or regenerate the key in the iOS app

429 errors — rate limits

Error message	Cause	Fix
Monthly message limit exceeded	Pro tier monthly limit of 1,000 reached	Wait for the monthly reset on the 1st, or reduce notification volume
Lifetime message limit exceeded	Free tier limit of 100 reached	Upgrade to Pro

See rate limits for full details on quotas and resets.

500 errors

Internal server errors are rare. If you receive a 500 response consistently, contact contact@thenotification.app.