# Adding the payment source
## Problem
You have a pending order with a selected payment method that is associated with a PayPal payment integration. You want to give your customer the possibility to select Paypal to process the payment.
## Solution
To add a PayPal payment source to an order, you have to create a PayPal payment source object and associate it with the order, as described in the Checkout guide.
{% content-ref url="../../checkout/adding-a-payment-source" %}
[adding-a-payment-source](https://docs.commercelayer.io/how-tos/placing-orders/checkout/adding-a-payment-source)
{% endcontent-ref %}
### Example
#### 1. Get the payment source type
{% tabs %}
{% tab title="Request" %}
The following request retrieves the attributes of the payment method associated with the order identified by the "jNbQLhMeqo" ID:
```javascript
curl -g -X GET \
'http://yourdomain.commercelayer.io/api/orders/jNbQLhMeqo?include=payment_method' \
-H 'Authorization: Bearer your-access-token' \
-H 'Accept: application/vnd.api+json'
```
{% endtab %}
{% tab title="Response" %}
On success, the API responds with a `200 OK` status code, returning the requested order object and the associated payment method:
{
"data": {
"id": "jNbQLhMeqo",
"type": "orders",
"links": {
"self": "https://yourdomain.commercelayer.io/api/orders/jNbQLhMeqo"
},
"attributes": {...},
"relationships": {
"market": {
"links": {...
}
},
"customer": {
"links": {...
}
},
"shipping_address": {
"links": {...
}
},
"billing_address": {
"links": {...
}
},
"payment_method": {
"links": {
"self": "https://yourdomain.commercelayer.io/api/orders/jNbQLhMeqo/relationships/payment_method",
"related": "https://yourdomain.commercelayer.io/api/orders/jNbQLhMeqo/payment_method"
},
"data": {
"type": "payment_methods",
"id": "PNMGGzsQMd"
}
},
"payment_source": {
"links": {...
}
},
"line_items": {
"links": {...
}
},
"shipments": {
"links": {...
}
},
},
"meta": {
"mode": "test"
}
},
"included": [
{
"id": "PNMGGzsQMd",
"type": "payment_methods",
"links": {
"self": "https://yourdomain.commercelayer.io/api/payment_methods/PNMGGzsQMd"
},
"attributes": {
"payment_source_type": "paypal_payments",
"name": "Paypal Payment",
"disabled_at": null,
"price_amount_cents": 0,
"price_amount_float": 0.0,
"formatted_price_amount": "€0,00",
"created_at": "2018-01-01T12:00:00.000Z",
"updated_at": "2018-01-01T12:00:00.000Z",
"reference": "",
"reference_origin": null,
"metadata": {}
},
"relationships": {
"market": {
"links": {...
}
},
"payment_gateway": {
"links": {...
}
}
},
"meta": {
"mode": "test"
}
}
]
}
{% endtab %}
{% endtabs %}
#### 2. Create the payment source and associate it with the order
{% tabs %}
{% tab title="Request" %}
The following request creates a PayPal payment object and associates it with the order identified by the "jNbQLhMeqo" ID:
```javascript
curl -g -X POST \
'http://yourdomain.commercelayer.io/api/paypal_payments' \
-H 'Accept: application/vnd.api+json' \
-H 'Authorization: Bearer your-access-token' \
-H 'Content-Type: application/vnd.api+json' \
-d '{
"data": {
"type": "paypal_payments",
"attributes": {
"return_url": "https://checkout.yourdomain.com/jNbQLhMeqo/paypal",
"cancel_url": "https://checkout.yourdomain.com/jNbQLhMeqo"
},
"relationships": {
"order": {
"data": {
"type": "orders",
"id": "jNbQLhMeqo"
}
}
}
}
}'
```
{% endtab %}
{% tab title="Response" %}
On success, the API responds with a `201 Created` status code, returning the created PayPal payment object:
{
"data": {
"id": "ZaDVpIqzeq",
"type": "paypal_payments",
"links": {
"self": "https://yourdomain.commercelayer.io/api/paypal_payments/ZaDVpIqzeq"
},
"attributes": {
"return_url": "https://checkout.yourdomain.com/jNbQLhMeqo/paypal",
"cancel_url": "https://checkout.yourdomain.com/jNbQLhMeqo",
"note_to_payer": null,
"paypal_payer_id": null,
"name": "paypal_payment #123",
"paypal_id": "PAYID-xxxxyyyyzzzz",
"status": "created",
"approval_url": "https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=EC-123abc456",
"payment_instrument":{...},
"created_at": "2018-01-01T12:00:00.000Z",
"updated_at": "2018-01-01T12:00:00.000Z",
"reference": null,
"reference_origin": null,
"metadata": {}
},
"relationships": {
"order": {
"links": {
"self": "https://yourdomain.commercelayer.io/api/paypal_payments/ZaDVpIqzeq/relationships/order",
"related": "https://yourdomain.commercelayer.io/api/paypal_payments/ZaDVpIqzeq/order"
}
}
},
"meta": {
"mode": "test"
}
}
}
{% endtab %}
{% endtabs %}
## Additional notes
#### Client-side payment approval
The successful PayPal payment creation returns all the pieces of information you need to get the payment approval in the PayPal client-side integration flow, such as the `paypal_id` and the `approval_url` — see [PayPal documentation](https://developer.paypal.com/docs/integration/direct/payments/paypal-payments/#get-payment-approval) for any reference.
#### Payment source nullification
PayPal payments are **synchronous**. When a Commerce Layer's `paypal_payment` is created and associated with an order, PayPal immediately creates a payment intent using the current order's `total_amount` as the amount to be authorized. If the order is modified before placement its amount and the original intent amount may differ, resulting in an error. To prevent that scenario previously created PayPal's payment sources are nullified in case of order edit/refresh (or if the payment method associated with the order is changed) and must be recreated.
{% hint style="info" %}
In view of this, make sure to set the payment source as **the last step** of your checkout implementation.
{% endhint %}
## More to read
See our documentation if you need more information on how to [retrieve an order](https://app.gitbook.com/s/RWJeylueWkzLadK710XZ/orders/retrieve), [include associations](https://app.gitbook.com/s/-LgByaSP8eKjad-MIuHE/including-associations), or [create a PayPal payment](https://app.gitbook.com/s/RWJeylueWkzLadK710XZ/paypal_payments/create).