Partner Documentation
Welcome. You are reading this because a payment platform (your client) has connected you to 4pay.online as a partner (merchant). This section covers everything you need to integrate payment acceptance into your product.
What you can do
| Capability | Description |
|---|---|
| Accept payments | Card, bank transfer, e-wallet, crypto — depending on your terminal configuration |
| Pay out funds | Send money to cards, bank accounts, or crypto wallets |
| Create payment links | Generate hosted payment pages and QR codes |
| Track transactions | Query status, aggregate by date/amount, export history |
| Receive webhooks | Real-time notifications on every status change |
| Save payment methods | Store cards for recurring charges |
| Let an agent pay | MCP, AP2, ACP and A2A — payments driven by AI agents |
What you need
Before making your first API call you need:
- An account — registered by your platform operator in their Admin Console
- An API key — generated in your Partner Area under Settings → API Keys
- At least one active terminal — configured by your platform operator with a payment provider
Quick Navigation
| I want to… | Link |
|---|---|
| Make my first payment in 15 minutes | Quick Start |
| Use a client library instead of raw HTTP | SDK — TypeScript, Python, PHP |
| Let an AI agent take payments | Agentic Payments |
| Understand how to authenticate | Authentication |
| Create a transaction | Transactions |
| Set up webhooks | Webhooks |
| Generate a payment link | Payment Links & QR |
| Look up an error | Error Reference |
| Run partnership, lease, instalment-sale or deposit contracts | Participatory Finance |
| Test without real money | Sandbox & Testing |
Base URL
https://4pay.online/api/v1 production
https://sandbox.4pay.online/api/v1 sandbox — build here first
The two environments are separate deployments with separate credentials; a sandbox key is
meaningless in production and the other way round. Inside a host, env in the request body picks
which side of it a transaction lives on.
The API uses JSON for all request and response bodies. All requests must include
Content-Type: application/json, x-api-key and x-organization-id — the key is resolved
inside the organization the second header names, and a request without it is refused.