# General information

Before integration, obtain your project **API key** in the merchant dashboard and review the [API request format](/pages/init-request): HTTP method, parameters, `sign` signature, and callback handling.

## Reference

API request format
Error codes (API)
Error codes (declines)
Payment types
Payout types
Transaction statuses
Balance request
Exchange rate
Create invoice
## Accepting payments

Choose a channel enabled on your project. Each method in the documentation includes parameters, signature, code examples, and a `sign` verification widget.

### Cards

Form payment
Host2host (GATE)
Subscriptions
Refunds
Payment status
### SBP

Form payment
Host2host (GATE)
Subscriptions
Refunds
Payment status
### Link payments

Form payment
Host2host (GATE)
Subscriptions
Refunds
Payment status
### ERIP

Form payment
Host2host (GATE)
Subscriptions
Refunds
Payment status
### SberPay

Form payment
Host2host (GATE)
Subscriptions
Refunds
Payment status
## Payouts

Card payout
PIX
SEPA
FPS
SBP
Payout status
## How the documentation is organized

| Section on the method page | Contents |
|  --- | --- |
| **How it works** | Business and user scenario |
| **Technical details** | URL, HTTP method, body format |
| **Request parameters** | Required and optional fields |
| **Signature generation** | MD5 formula and verification widget |
| **Request examples** | Node.js, Python, PHP, cURL |
| **Notifications (callbacks)** | POST JSON to your `notify_url` |


Request and callback signatures are described in [API request format](/pages/init-request). Each operation page includes an interactive `sign` verification tool.