Errors

Every error response carries the same object under error, next to a request_id:

{
  "error": {
    "code": "text_too_long",
    "message": "the text needs more than 10 segments",
    "param": "text",
    "doc_url": "https://docs.06line.com/docs/errors#text_too_long"
  },
  "request_id": "req_01jbq5a3x9e2k7m4t6v8r0c1yb"
}

Match on code; message is for humans and may change. param, when present, names the offending field of the body or the query (to, text, client_ref, limit, peer, url, events…). retry_after_ms comes with rate_limited only. doc_url points at the row of the code below.

Code	Cause	What to do
`invalid_request`	Malformed JSON, unknown field, missing or wrongly typed field	Fix the request; see `param`
`unauthorized`	Missing, unknown, revoked or expired credential	Get a valid credential
`forbidden`	The credential cannot do this: an ephemeral key on SMS, webhook endpoints or ephemeral keys, or placing a call on another line	Call from your server with an API key
`not_found`	The line, call, message or session does not exist in your company, or is out of reach of a key restricted to one line	Check the id
`invalid_number`	The number is not E.164	Send `+` and the country code, no spaces
`text_too_long`	More than 10 segments	Shorten the text, or avoid characters that force UCS-2
`line_offline`	The line is not registered on the network	Wait for `line.state` with `online: true`
`line_busy`	A call is already in progress on the line or on the WebRTC session, or another session answered first	Wait for the call to end
`call_not_active`	Answering a call that is no longer ringing (hanging up an ended call is not an error: it returns the call)	Ignore; the call was answered or is over
`rate_limited`	More than 25 requests a second on average, or 100 at once, for the key	Retry after `retry_after_ms`
`internal`	Our fault	Retry with the same `client_ref`: a message saved but never sent is sent then, never twice; contact support with `request_id`

A message that ends failed carries its reason in error, in the API and in the sms.status webhook:

Code	Cause	What to do
`send_failed`	The modem or the network refused a segment	Check the number; retry later with a new `client_ref`
`delivery_failed`	The network reported the recipient will never get it (unknown or barred number)	Check the number
`line_offline`	The line went offline before the message left	Wait for the line to be online, then send again

The browser SDK adds codes of its own, for what happens in the browser (microphone_denied, speaker_not_found, user_gesture_required…): see its errors. A call it ends because another session answered it carries the end reason answered_elsewhere.