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

# Overview

> Understand what Payment Element is, when to use it, and how it fits into Pagou's card payment lifecycle.

Payment Element is the recommended browser integration for new card checkouts.

## When to use it

* You are building a new card checkout.
* You want hosted card fields instead of collecting raw card data.
* You need 3D Secure in the same browser flow.
* Your backend should remain the owner of transaction creation and fulfillment state.

## Browser vs backend

Browser responsibilities:

* load the Pagou script
* mount the card field
* submit through `elements.submit(...)`
* continue browser-side challenge flow when required

Backend responsibilities:

* authenticate with secret credentials
* create `POST /v2/transactions`
* persist `external_ref`, transaction ID, and `requestId`
* fulfill only from webhook or reconciliation state

## Backend request example

```json theme={null}
{
  "external_ref": "order_2001",
  "amount": 2490,
  "currency": "BRL",
  "method": "credit_card",
  "token": "pgct_token_from_browser",
  "installments": 1
}
```

## Backend response example

```json theme={null}
{
  "success": true,
  "requestId": "0190a2b4-18a7-7de0-9a43-69b7cf261201",
  "data": {
    "id": "018f1f2e-7b43-7c9a-8d3e-1a2b3c4d5e70",
    "status": "three_ds_required",
    "method": "credit_card",
    "next_action": {
      "type": "three_ds_challenge"
    }
  }
}
```

Return this payload to the browser unchanged. `next_action` is opaque — `elements.submit(...)` reads
it and completes card authentication for you.

## Common error

```json theme={null}
{
  "type": "https://api.pagou.ai/problems/validation-error",
  "title": "Validation Error",
  "status": 422,
  "detail": "The request contains invalid data.",
  "errors": [
    {
      "field": "token",
      "message": "Token is required for credit card payments",
      "code": "invalid_type"
    }
  ]
}
```

## Start here

* [Quickstart](/frontend/payment-element/quickstart)
* [Accept a Payment](/frontend/payment-element/accept-a-payment)
* [3D Secure](/frontend/payment-element/three-d-secure)