How to Build a Monero Payment Gateway — Technical Guide
# How to Build a Monero Payment Gateway (Technical Guide)
I built a Monero payment gateway with 0.5% fees and open-sourced the approach. Here's how it works.
## Architecture
Three components:
1. monero-wallet-rpc — generates subaddresses, monitors payments
2. Flask REST API — serves invoice creation and status endpoints
3. SQLite — stores invoices, zero-config
## Wallet Setup
```bash
monero-wallet-rpc \
--wallet-file /data/wallet \
--daemon-host xmr-node.cakewallet.com \
--rpc-bind-port 18083 \
--password "" --disable-rpc-login
```
## Creating Invoices
Each invoice gets a unique subaddress via RPC:
POST /api/invoice {amount: 0.05, webhook_url: "..."}
→ Wallet generates fresh subaddress (create_address RPC)
→ Store {id, subaddress_index, amount, webhook_url} in SQLite
→ Return address to customer
## Payment Detection
Background thread polls get_transfers every 30 seconds:
```python
transfers = wallet_rpc("get_transfers", {"in": True})
for tx in transfers:
idx = tx["subaddr_index"]["minor"]
invoice = lookup_invoice(idx)
if tx["confirmations"] >= needed:
mark_paid(invoice, tx["amount"])
fire_webhook(invoice, tx["txid"])
```
## Why 0.5%?
NowPayments/CoinPayments charge 1%. Running your own wallet-rpc costs nothing except server time. The 0.5% fee covers maintenance and keeps it sustainable.
Full source + running instance: https://brief-propecia-accent-constantly.trycloudflare.com/pay
Built for the Monero community. Feedback and contributions welcome.
#Monero #dev #python #selfhosted #privacy
