Payment Acceptance Quick Start

Prerequisites

Merchant Account: Contact sales for a GoPay merchant account
API Key Pair: Create an Ed25519 key pair with the c2b permission — see Authentication
Server Environment: A backend to securely sign and send API requests — never sign requests in a browser or mobile app

Implementation Steps

Step 1: Sign the Request
Step 2: Create Payment
Step 3: Redirect to Checkout

Every request is authenticated with a detached Ed25519 signature sent in HTTP headers (X-Public-Key, X-Signature, X-Timestamp, X-Request-ID) — nothing auth-related goes in the JSON body.The full scheme, including ready-to-use signing helpers in Node.js, Python, and Go, is on the Authentication page. In short:

Hash your exact request body bytes with SHA-256
Build the v1 canonical string from the method, host, path, timestamp, request ID, and body hash
Sign it with your Ed25519 private key and send X-Signature: ed25519=<base64>

Also send the optional Idempotency-Key header if you retry on network errors.

Send a POST request to /api/v1/initiate-payment:

Parameter	Type	Required	Description
`merchantId`	string	Yes	Your merchant ID
`amount`	number	Yes	Payment amount (> 0)
`currency`	string	Yes	Currency code (see supported list in the API reference)
`phoneNumber`	string	Yes	Customer phone number (10–15 digits, optional `+`)
`successUrl`	string	Yes	HTTPS URL to redirect after successful payment
`failUrl`	string	Yes	HTTPS URL to redirect after failed payment
`notifyUrl`	string	Yes	HTTPS URL for the settlement webhook

All three URLs must be absolute HTTPS URLs — plain HTTP is rejected.

On success the API returns:

{
    "checkoutUrl": "https://checkout.gopay.example.com/?token=eyJhbGciOi...",
    "sessionId": 12345
}

Redirect your customer to checkoutUrl to complete the payment
Store sessionId for correlation and support
After completion the customer is redirected to your successUrl or failUrl
The authoritative settlement result arrives as a signed webhook on your notifyUrl — see C2B Callbacks

Getting Started

Accept Payments

Make Transfers

Webhooks

Resources

Prerequisites

Implementation Steps

Next Steps

API Reference

Code Examples

​Prerequisites

​Implementation Steps

​Next Steps

API Reference

Code Examples

Prerequisites

Implementation Steps

Next Steps