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DevelopersREST + JSON · Bearer auth

Stablecoin Payment API.

One endpoint to integrate. Five chains. USDC + USDT. Built for non-custodial merchant payments — funds settle directly on-chain to your wallet, no intermediary holds them.

201 CREATED · 12 msPOST /v1/payments
{
  "id": "8f3a9c2d-1b6e-4d8a-9c2e-3f4b5d6e7a8c",
  "status": "ACTIVE",
  "amount": "49.99",
  "currency": "USD",
  "title": "Order #1234",
  "externalId": "order-1234",
  "acceptedChains": [1, 42161, 8453, 137, 56],
  "acceptedTokens": ["USDC", "USDT"],
  "pymstrFee": "0.50",
  "merchantFee": "49.49",
  "paymentUrl": "https://pay.pymstr.com/p/8f3a9c2d-1b6e-4d8a-9c2e-3f4b5d6e7a8c",
  "expiresAt": "2026-05-20T07:00:00Z",
  "createdAt": "2026-05-19T07:00:00Z"
}
//The flowone POST → on-chain settlement01/05
01

POST /v1/payments

You create the payment with an amount + currency. We return a paymentUrl.

02

Share the URL

Send it in an email, link it from your invoice, or redirect from your app.

03

Customer pays

They sign in (social login or wallet), pick from the chains + tokens you accept, sign one transaction.

04

Webhook fires

payment.completed arrives at your endpoint, HMAC-signed. Funds are already in your wallet.

//First callcurl · javascript · python02/05

One POST. That's the integration.

Send an amount and a currency, get back a paymentUrl. No checkout build, no wallet UX to design, no chain-selection state machine to wire up.

POST /v1/paymentsapi.pymstr.com
curl -X POST https://api.pymstr.com/v1/payments \
  -H "Authorization: Bearer pk_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "amount": "49.99",
    "currency": "USD",
    "title": "Order #1234",
    "externalId": "order-1234"
  }'
//Chains + tokens5 chains · 2 stablecoins05/05

Where your customers can pay from.

Per-payment, you can restrict which chains and tokens are accepted via the acceptedChains and acceptedTokens fields. Default: all supported.

ChainChain IDTokensAvg gasBlock time
Ethereum1USDC, USDT~$2-1015 sec
Arbitrum One42161USDC, USDT~$0.102 sec
Base8453USDC~$0.052 sec
Polygon137USDC, USDT~$0.012 sec
BNB Smart Chain56USDT~$0.103 sec

Build with the stablecoin rail.

One endpoint. Real production code. 1% flat. Non-custodial — funds settle directly on-chain to your wallet.