Guides

Errors

Every error is a JSON object with an error message. Validation errors also list each problem in errors.

AnyoneIn uses standard HTTP status codes. Anything in the 2xx range worked; 4xx means something in the request needs changing; 5xx means something went wrong on our side.

Error shape

Every error response has the same shape: a JSON object with an error string, written to be read by a person. Validation errors add an errors array with one message per problem.

Note

Match on the status code, and on errors for validation. The wording of messages can improve over time, so don't parse them. Error codes you can match on are on the roadmap.

Response409 Conflict

{
  "error": "This confirmation is already closed."
}

Response422 Unprocessable Entity

{
  "error": "customer.name is required. order.date must be a date like 2026-10-14.",
  "errors": [
    "customer.name is required.",
    "order.date must be a date like 2026-10-14."
  ]
}

Status codes

Status	`error`	Meaning
`200`		It worked
`201`		Created
`400`	`Bad JSON`	The body isn't valid JSON
`401`	A message asking for the key	The `Authorization` header is missing or the key is wrong. See Authentication
`404`	`No confirmation with that id.`	No confirmation has that `id`
`404`	`Not found`	The path doesn't exist
`405`	`Method not allowed`	Wrong method for the path, such as `GET` on `/advance`
`409`	`This confirmation is already closed.`	You tried to advance or cancel a closed confirmation
`409`	`Nothing left to send.`	You tried to advance when every step has gone out
`413`	`Request too large.`	The body is over 40 KB
`422`	Every problem, joined	Validation failed. Details in `errors`
`429`	`That’s a lot of confirmations. Try again in an hour.`	Too many creates. See Rate limits
`500`	`Something went wrong.`	Our fault. Retry with backoff, and tell us if it persists

422 validation

Creating a confirmation checks everything at once and reports every problem in one response, so you can fix them in one go. The full list of messages is in Create a confirmation.

Retrying

Status	Retry?
`400`, `401`, `404`, `405`, `413`, `422`	No. Fix the request first
`409`	No. Retrieve the confirmation to see its current state
`429`	Yes, later. The limit is a rolling hour
`500`, network errors, timeouts	Yes, with backoff. For creates, read Idempotency first

Base URL https://api.anyonein.co.uk/v1 is a placeholder until the production domain is confirmed. Found a mistake? Tell us.

#Error shape

#Status codes

#422 validation

#Retrying

Error shape

Status codes

422 validation

Retrying