Errors & Rate Limits

SendPipe uses standard HTTP status codes and a consistent error response format across all endpoints.

Error Format

json

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid email address in 'to' field",
    "field": "to",
    "docs": "https://docs.sendpipe.io/errors#VALIDATION_ERROR"
  }
}

HTTP Status Codes

Status	Meaning
200	OK — request succeeded
201	Created — resource created successfully
204	No Content — deletion successful
400	Bad Request — invalid parameters or body
401	Unauthorized — missing or invalid authentication
403	Forbidden — insufficient permissions or IP blocked
404	Not Found — resource does not exist
409	Conflict — resource already exists (e.g., duplicate domain)
429	Rate Limited — too many requests
500	Server Error — something went wrong on our end

Common Error Codes

Code	Description
`UNAUTHORIZED`	Missing or invalid API key / session token
`FORBIDDEN`	IP address blocked or insufficient role permissions
`NOT_FOUND`	Resource not found in the current project scope
`VALIDATION_ERROR`	Request body failed schema validation
`RATE_LIMIT_EXCEEDED`	Too many requests — retry after the reset time
`SLUG_ALREADY_EXISTS`	Organization or project slug already taken
`DOMAIN_ALREADY_EXISTS`	Domain already registered in this project
`DOMAIN_HAS_ACTIVE_MESSAGES`	Cannot remove domain with queued/sending messages
`EMAIL_ALREADY_EXISTS`	Account with this email already exists
`BILLING_NOT_CONFIGURED`	Stripe billing is not configured on the server

Rate Limit Headers

Every response includes rate limit information:

`X-RateLimit-Limit`	Maximum requests allowed in the current window
`X-RateLimit-Remaining`	Requests remaining in the current window
`X-RateLimit-Reset`	Unix timestamp when the window resets

When rate limited, wait until X-RateLimit-Reset before retrying. The response body will have error code RATE_LIMIT_EXCEEDED.