> ## Documentation Index
> Fetch the complete documentation index at: https://finconnect.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# BaseProvider interface reference

> Reference for the abstract baseProvider class that all FinConnect provider implementations must extend, defining the core payment methods.

`baseProvider` is the abstract base class that all FinConnect providers extend. It defines the contract each provider must implement. You interact with providers through `FintechSDK`, but understanding the interface helps when reading provider-specific docs.

## Interface definition

```typescript theme={null}
abstract class baseProvider {
  abstract authenticate(): Promise<string>;
  abstract initiateUssdPushRequest(params: { payload: any; ipnId?: string }): Promise<any>;
  async registerIpn(ipnUrl: string, ipnNotificationType: "GET" | "POST"): Promise<any>;
}
```

## Methods

| Method                      | Abstract | Description                                                                                                              |
| --------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------ |
| `authenticate()`            | Yes      | Fetches an auth token from the provider. Called automatically before each request — you do not need to call it yourself. |
| `initiateUssdPushRequest()` | Yes      | Sends the USSD push payment request. Called by `FintechSDK.pay()`.                                                       |
| `registerIpn()`             | No       | Registers an IPN URL with the provider. The base implementation throws — providers override this when supported.         |

### `authenticate()`

```typescript theme={null}
abstract authenticate(): Promise<string>
```

Fetches a valid auth token from the provider API. The token is used in the `Authorization` header for subsequent requests. Each provider implements its own auth mechanism — PesaPal uses OAuth2 bearer tokens; ClickPesa uses JWT.

### `initiateUssdPushRequest()`

```typescript theme={null}
abstract initiateUssdPushRequest(params: { payload: any; ipnId?: string }): Promise<any>
```

Sends the USSD push payment request to the provider. The exact shape of `payload` and how `ipnId` is used depends on the provider implementation.

### `registerIpn()`

```typescript theme={null}
async registerIpn(ipnUrl: string, ipnNotificationType: "GET" | "POST"): Promise<any>
```

The base implementation always throws `"IPN registration not supported by this provider"`. Providers that support IPN registration (currently only PesaPal) override this method.

<Note>
  ClickPesa does not override `registerIpn()`, so calling `sdk.registerIpn()` with a ClickPesa instance throws `"IPN registration not supported by this provider"`.
</Note>