Guides

Errors

Every error has the same shape, with a code that never changes meaning. Branch on the code; show the message.

409 Conflict

{
  "error": {
    "code": "conflict",
    "message": "This campaign is already sending"
  }
}

The message names the field when the input is wrong, and says what to do when a rule stops the action. MCP tools answer the same object in an error result. Sending a campaign that is already sending or sent answers conflict, so a retried send never goes out twice.

Code	Status	Meaning
`unauthorized` The API key is missing, malformed, unknown or revoked.	401	The API key is missing, malformed, unknown or revoked.
`forbidden` The key's level doesn't allow this action: a signups only key can only add contacts.	403	The key's level doesn't allow this action: a signups only key can only add contacts.
`not_found` The newsletter, campaign, author, contact, segment, domain or key isn't in this account.	404	The newsletter, campaign, author, contact, segment, domain or key isn't in this account.
`validation_failed` The input doesn't match the schema or breaks a rule. The message names the field.	400	The input doesn't match the schema or breaks a rule. The message names the field.
`conflict` The resource's state doesn't allow it, e.g. sending a campaign that is already sending or sent. Retrying won't help.	409	The resource's state doesn't allow it, e.g. sending a campaign that is already sending or sent. Retrying won't help.
`revision_conflict` The draft changed since the revision sent with update_campaign: get_campaign has the new one to start from.	409	The draft changed since the revision sent with update_campaign: get_campaign has the new one to start from.
`rate_limited` Too many requests with this key, or too many of one action for the account, whose keys, apps and dashboard share its limits. Wait and retry.	429	Too many requests with this key, or too many of one action for the account, whose keys, apps and dashboard share its limits. Wait and retry.
`sender_not_allowed` The from address isn't on a domain this account added, or that domain isn't verified.	422	The from address isn't on a domain this account added, or that domain isn't verified.
`send_check_failed` A pre-send check failed: no postal address, subject, content or author, the email is over 100 KB, or its segment was deleted.	422	A pre-send check failed: no postal address, subject, content or author, the email is over 100 KB, or its segment was deleted.
`no_recipients` Nobody is left to send to.	422	Nobody is left to send to.
`sending_disabled` Sending is turned off on this server.	503	Sending is turned off on this server.
`unavailable` A service the action needs isn't configured or didn't answer. Retry later.	503	A service the action needs isn't configured or didn't answer. Retry later.
`internal_error` Something failed on Postroom's side.	500	Something failed on Postroom's side.