> ## Documentation Index
> Fetch the complete documentation index at: https://docs.v2.topup.com.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Back to Back Integration

> Direct PayIn integration for Colombia without redirecting users to checkout.

# Back to Back

When the **Enlace PSE/TRANSFIYA/BREB directo** configuration is enabled in the admin TumiPay backoffice, you can execute PayIn transactions directly without redirecting the user to the checkout. The API will return a direct PSE link or a Transfiya confirmation depending on the payment method.

## Required Fields

In addition to the standard body parameters of the `POST /payin` endpoint, provide the following parameters:

## PSE Integration

## Retrieve available banks

Use the `GET /api/v1/pse/banks` endpoint to fetch the list of financial institutions that
the user can choose from.

```json theme={null}
{
    "code": "01",
    "status": "SUCCESS",
    "data": [
        {
            "code": "1507",
            "name": "NEQUI",
            "image": "https://assets.tumipay.co/images/payment_method/nequi.webp"
        },
        {
            "code": "1551",
            "name": "DAVIPLATA",
            "image": "https://assets.tumipay.co/images/payment_method/daviplata.webp"
        },
        {
            "code": "1007",
            "name": "BANCOLOMBIA",
            "image": "https://assets.tumipay.co/images/payment_method/bancolombia.webp"
        }
    ]
}
```

## Example request

* `bank` – Required only when `payment_method` is `PSE`. **Must** be the `code` field retrieved from the `GET /api/v1/pse/banks` endpoint.
* `person_type` – Required only when `payment_method` is `PSE` (`NATURAL` or `JURIDICA`)

```json theme={null}
{
    "reference": "3cNPNGbX1meM",
    "amount": 50000,
    "currency": "COP",
    "country": "CO",
    "payment_method": "PSE",
    "description": "Test PayIn",
    "customer_data": {
        "person_type": "NATURAL",
        "bank": "1077",
        "legal_doc": "1045689877",
        "legal_doc_type": "CC",
        "phone_code": "57",
        "phone_number": "3121234567",
        "email": "approved@tumipay.co",
        "full_name": "John Doe"
    },
    "expiration_time": 720,
    "ipn_url": "{{webhook}}",
    "redirect_url": "https://your-domain.com/payment/success"
}
```

## Example response

```json theme={null}
{
    "code": "01",
    "status": "SUCCESS",
    "message": "Pago generado correctamente",
    "data": {
        "ticket": "abc123",
        "payment_url": "https://registro.desarrollo.pse.com.co/PSENF/index.html?enc=abc123",
        "type": "pse_payment"
    }
}
```

## Example Transfiya

* `phone_number` – Must match the user's registered Transfiya phone when using `TRANSFIYA`.

```json theme={null}
{
    "code": "01",
    "status": "SUCCESS",
    "message": "Pago generado correctamente",
    "data": {
        "confirmation": "La transacción ha sido creada y está pendiente de confirmación por parte del usuario",
        "type": "transfiya_confirmation"
    }
}
```

## Example Bre-B

*

```json theme={null}
{
    "code":"01",
    "status":"SUCCESS",
    "message":"Pago generado exitosamente",
    "data":{
        "ticket": "abc123",
        "key_value":"@tumipaybreb",
        "type": "payment_reference"
    }
}
```