API Reference

All Pay At Table communication happens over a WebSocket. Your EPoS connects to yetipay's PAT endpoint, and both sides use JSON-RPC for requests and responses.

info

The full AsyncAPI spec was previously at /api/pat/epos. Use the original spec for complete schema details.

Connection

Your POS opens a WebSocket connection to the yetipay PAT endpoint. Every message — table lists, locks, receipts, payments, unlocks — uses the JSON-RPC format.

Messages

Message	Direction	Description
tableListRequest	Terminal → EPoS	Requests the list of open tables
tableListResponse	EPoS → Terminal	Your response. Array of table IDs (or empty). Include currency if you return any tables.
tableLockRequest	Terminal → EPoS	Sent after the waiter picks a table. Contains tableId.
tableLockResponse	EPoS → Terminal	Your response. Set confirmed to true to grant the lock. If true, include amount (minor units) and currency.
posReceiptRequest	Terminal → EPoS	Terminal wants a receipt printed before payment
posReceiptResponse	EPoS → Terminal	Your response. receiptLines — ordered list of printable lines (text, separators, barcode, image).
transactionResponse	Terminal → EPoS	Sent after the terminal takes one or more payments. Totals plus breakdown (method, scheme, amounts, auth code, etc.).
finalPOSReceiptRequest	Terminal → EPoS	Requests a final receipt after payment (if connection string includes final-pos-receipt)
finalPOSReceiptResponse	EPoS → Terminal	Your response. Same line-based format as posReceiptResponse.
tableUnlock	Terminal → EPoS	Terminal is done. EPoS can make the table editable again.
errorMessage	Either	Something went wrong. Code and message. Some include userMessage to show staff (e.g. terminal unavailable).