Accepting Monero Payments

The Basics

Monero works a little differently to what you may have become accustomed to from other cryptocurrencies. In the case of a digital currency like Bitcoin and its many derivatives merchant payment systems will usually create a new recipient address for each payment or user.

However, because Monero has stealth addresses there is no need to have separate recipient addresses for each payment or user, and a single account address can be published. Instead, when receiving payments a merchant will provide the person paying with a "payment ID".

A payment ID is a hexadecimal string that is 64 characters long, and is normally randomly created by the merchant. An example of a payment ID is: 666c75666679706f6e7920697320746865206265737420706f6e792065766572

Checking for a Payment in monero-wallet-cli

If you want to check for a payment using monero-wallet-cli you can use the "payments" command followed by the payment ID or payment IDs you want to check. For example:

[wallet 49VNLa]: payments 666c75666679706f6e7920697320746865206265737420706f6e792065766572 payment transaction height amount unlock time <666c75666679706f6e79206973207> <7ba4cd810c9b4096869849458181e98e> 441942 30.00000 0 [wallet 49VNLa]:





If you need to check for payments programmatically, then details follow the next section.

Receiving a Payment Step-by-Step

Generate a random 64 character hexadecimal string for the payment
Communicate the payment ID and Monero address to the individual who is making payment
Check for the payment using the "payments" command in monero-wallet-cli

Checking for a Payment Programatically

In order to check for a payment programatically you can use the get_payments or get_bulk_payments JSON RPC API calls.

get_payments: this requires a payment_id parameter with a single payment ID.

get_bulk_payments: this is the preferred method, and requires two parameters, payment_ids - a JSON array of payment IDs - and an optional min_block_height - the block height to scan from.

An example of returned data is as follows:

[ monero->~ ]$ curl -X POST http://127.0.0.1:18500/json_rpc -d '{"jsonrpc":"2.0","method":"get_bulk_payments","id":"test", "params":{"payment_ids": ["666c75666679706f6e7920697320746865206265737420706f6e792065766572"]}}' -H "Content-Type: application/json" { "id": "test", "jsonrpc": "2.0", "result": { "payments": [{ "amount": 30000000000000, "block_height": 441942, "payment_id": "666c75666679706f6e7920697320746865206265737420706f6e792065766572", "tx_hash": "7ba4cd810c9b4096869849458181e98e18b6474ab66415de0f4ccf7ab1162fdf", "unlock_time": 0 }] } }

It is important to note that the amounts returned are in base Monero units and not in the display units normally used in end-user applications. Also, since a transaction will typically have multiple outputs that add up to the total required for the payment, the amounts should be grouped by the tx_hash or the payment_id and added together. Additionally, as multiple outputs can have the same amount, it is imperative not to try and filter out the returned data from a single get_bulk_payments call.

Before scanning for payments it is useful to check against the daemon RPC API (the get_info RPC call) to see if additional blocks have been received. Typically you would want to then scan only from that received block on by specifying it as the min_block_height to get_bulk_payments.

Programatically Scanning for Payments

Get the current block height from the daemon, only proceed if it has increased since our last scan
Call the get_bulk_payments RPC API call with our last scanned height and the list of all payment IDs in our system
Store the current block height as our last scanned height
Remove duplicates based on transaction hashes we have already received and processed