Skip to main content

authentication_failed

Epostix could not identify the caller, so the request stopped at the door. Nothing was sent and nothing was charged.

Status: 401

{
  "status": 401,
  "type": "authentication_failed",
  "message": "Invalid or missing API key",
  "request_id": "req_01J8K2P...",
  "doc_url": "https://docs.epostix.com/errors/authentication_failed"
}

Why you got this​

  • The Authorization header is absent, or its value does not begin with Bearer .
  • The key was truncated, wrapped in quotes, or given a trailing newline when it was copied into your environment.
  • The key was deleted and no longer exists.
  • The prefix does not match the environment you are calling: a tix_test_ key used for live traffic, or a tix_live_ key used for test traffic.

How to fix it​

Send the key as Authorization: Bearer tix_live_... against https://api.epostix.com/v1, with no quotes and no surrounding whitespace. Check the prefix against the environment you meant to call before you look anywhere else.

If the key itself looks correct, check which value your deployment actually loaded. Reading the wrong variable is a more common cause than a bad key. Authentication covers the header format, and Test mode covers the two prefixes.

Is it safe to retry​

No, not unchanged. The same credentials fail the same way every time. Correct the header or the key and send the request again. Nothing was created, so there is no duplicate to avoid.