# Check Source

## Check the Source

With this request, you should check the callback source and make sure it comes from FCF Pay.

You will receive the`unique_id` in the [deposit callback](/reference/api-requests-v1-deprecated/deposit-callback.md)*.*

{% tabs %}
{% tab title="cURL" %}

```
curl --location --request POST 'https://merchant.fcfpay.com/api/v1/check-source' \
--header 'Authorization: Bearer YOUR_LIVE_API_KEY' \
--header 'Content-Type: application/json' \
--data-raw '{
	"unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
}'
```

{% endtab %}

{% tab title="JavaScript" %}

```
var myHeaders = new Headers();
myHeaders.append("Authorization", "Bearer YOUR_LIVE_API_KEY");
myHeaders.append("Content-Type", "application/json");

var raw = JSON.stringify({
  "unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
});

var requestOptions = {
  method: 'POST',
  headers: myHeaders,
  body: raw,
  redirect: 'follow'
};

fetch("https://merchant.fcfpay.com/api/v1/check-source", requestOptions)
  .then(response => response.text())
  .then(result => console.log(result))
  .catch(error => console.log('error', error));
```

{% endtab %}

{% tab title="Node.js" %}

```
var request = require('request');
var options = {
  'method': 'POST',
  'url': 'https://merchant.fcfpay.com/api/v1/check-source',
  'headers': {
    'Authorization': 'Bearer ',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    "unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
  })
};
request(options, function (error, response) {
  if (error) throw new Error(error);
  console.log(response.body);
});
```

{% endtab %}

{% tab title="PHP" %}

```
<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://merchant.fcfpay.com/api/v1/check-source',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_POSTFIELDS =>'{
    "unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
  }',
  CURLOPT_HTTPHEADER => array(
    'Authorization: Bearer ',
    'Content-Type: application/json'
  ),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;
```

<table><thead><tr><th width="345.0526315789474">Field</th><th>Description</th></tr></thead><tbody><tr><td>unique_id</td><td>The unique id you mus get from deposit callback</td></tr><tr><td></td><td></td></tr></tbody></table>
{% endtab %}

{% tab title="Python" %}

```
import requests
import json

url = "https://merchant.fcfpay.com/api/v1/check-source"

payload = json.dumps({
  "unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
})
headers = {
  'Authorization': 'Bearer YOUR_LIVE_API_KEY',
  'Content-Type': 'application/json'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

```

{% endtab %}
{% endtabs %}

## Check the source.

<mark style="color:green;">`POST`</mark> `https://merchant.fcfpay.com/api/v1/check-source`

#### Headers

| Name                                            | Type   | Description         |
| ----------------------------------------------- | ------ | ------------------- |
| Authorization<mark style="color:red;">\*</mark> | String | Bearer {{API\_KEY}} |

#### Request Body

| Name       | Type   | Description                       |
| ---------- | ------ | --------------------------------- |
| unique\_id | string | Got from deposit callback request |

{% tabs %}
{% tab title="200: OK Transaction exists" %}

```javascript
{
  "success": true,
  "data": {
    "unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
  },
  "message": "Transaction exists."
}
```

{% endtab %}

{% tab title="200: OK Merchant Authentication problem!" %}

```javascript
{
  "success": false,
  "data": [],
  "message": "Merchant Authentication problem!"
}
```

{% endtab %}

{% tab title="401: Unauthorized The given data was invalid!" %}

```javascript
{
  "success": false,
  "data": {
    "test": "test"
  },
  "message": "The given data was invalid!",
  "errors": {
    "unique_id": [
      "The unique id field is required."
    ]
  }
}
```

{% endtab %}

{% tab title="401: Unauthorized Transaction does not exist!" %}

```javascript
{
  "success": false,
  "data": {
    "unique_id": "0x9cf24f76778e517511f6178f114a1d3e95e3c7fdbfcbe52a961b6d748e860849_0"
  },
  "message": "Transaction does not exist!"
}
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://api-docs.fcfpay.com/reference/api-requests-v1-deprecated/check-source.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.