Responses and errors

The reader looks mostly at the status of the answer. An error with a body is JSON {"error":"<description>","code":"<stable code>"}.

What the reader does with an answer

Answer	Reader
200	done (the punch is removed from the reader)
304	nothing changed (/users, /presence)
400	drops that one record, sends the rest
401, 403	shows Chmura odrzucila dane logowania - polacz ponownie, punches wait on the reader
404	treats it as a wrong address: drops nothing, retries later
429, 5xx, no answer	retries on the next sync

Rules for your server

• No route answers 404 to a correct request (except /claim with a wrong code). A 404 for an unknown card would block the reader's queue forever.
• 400 only for a record you can never store. The reader drops it.
• 401 with the header WWW-Authenticate: Basic realm="rcp" for a wrong login or password, also for a reader deleted in your system.
• JSON without spaces, no compressed answers.
• An answer within 8 seconds.

Reconnecting a reader

When you take a reader's access away (new password or deletion), the reader stays paired but every route gets 401. To connect it again: Disconnect in the reader's panel, then a new pairing code. Punches waiting on the reader then arrive with the new credentials.

GET /hello

A connection test:

{"device":"Main entrance","organization":"My company","tz":"Europe/Warsaw","epoch":1793404800}

epoch is the server's time (unix seconds), useful to check the reader's clock.