> For a complete page index, fetch https://docs.transak.com/llms.txt

# Transaction Session API

POST https://api-gateway-stg.transak.com/api/v2/transaction-session
Content-Type: application/json

Creates a Headless Google Pay transaction session. Returns a `sessionId` for your integration. Requires a valid partner access token and approved KYC where applicable.

**Note:** Ensure the `quoteId` was generated with `paymentMethod` set to `google_pay`.

Reference: https://docs.transak.com/api/whitelabel/payments/headless-google-pay/transaction-session-api

## Request

### Headers

- `x-user-ip` (string, required) — End user's originating IP. More details [here](/guides/mandatory-security-changes#user-ip-header-in-apis)
- `x-api-key` (string, required) — Your Partner API key. You can find this in the [Partner Dashboard](https://docs.transak.com/guides/how-to-create-partner-dashboard-account#open-the-developers-section).
- `x-access-token` (string, optional) — Your Partner Access Token. Please refer [here](/guides/how-to-create-partner-access-token) for a tutorial on generating your access token. Note: This is applicable only for [Auth Reliance Flows](/features/auth-reliance)
- `x-user-identifier` (string, optional) — The authenticated user's email address. Note: This is applicable only for [Auth Reliance Flows](/features/auth-reliance).
- `authorization` (string, optional) — Authorization token is the accessToken received from the API -` api/v2/auth/verify` Note: This is not applicable for [Auth Reliance Flows](/features/auth-reliance)

### Body (application/json)

- `quoteId` (string, required) — Quote ID from the [Quotes API](/api/whitelabel/lookup/get-quote).
- `walletAddress` (string, required) — Destination crypto wallet address.
- `successUrl` (string, required) — Redirect URL on payment success.
- `failureUrl` (string, required) — Redirect URL on payment failure.
- `config` (object, optional) — Additional optional UI configuration passed through to the session.
  - `colorMode` (enum, optional) — UI color mode for the Google Pay flow.
    - Allowed values: `DARK`, `LIGHT`
  - `borderRadius` (string, optional) — CSS border radius applied to UI elements. Only `px` and `rem` units are supported.
  - `height` (string, optional) — CSS height applied to the Google Pay container. Only `px` and `rem` units are supported.
- `billingAddress` (object, optional) — Auto-fetched from user profile if omitted (Google Pay only).
  - `addressLine1` (string, optional)
  - `addressLine2` (string, optional)
  - `city` (string, optional)
  - `state` (string, optional)
  - `postCode` (string, optional)
  - `country` (string, optional)
  - `countryCode` (string, optional)

## Response

### 200

Success

- `data` (object, required)
  - `sessionId` (string, required) — Session token for the Headless Google Pay flow.
  - `expiresAt` (datetime, required) — Session expiration timestamp.

## Examples

**Request**

```json
{
  "quoteId": "",
  "walletAddress": "",
  "successUrl": "",
  "failureUrl": "",
  "config": {
    "colorMode": "DARK",
    "borderRadius": "8px",
    "height": "48px"
  }
}
```

**Response**

```json
{
  "data": {
    "sessionId": "eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCJ9.eyJvdHQiOiJjOTU4NTQ0MzQzZjI4YjM4NGQ5OGExM2JjZmU3OTk2YSIsImlhdCI6MTc4MDM2ODM3MywiZXhwIjoxNzgwMzY4OTczfQ.BLlwJbGrH-jRBwAWhJgPIDmcDFYvpIOZCMEVaZhhB4RC3LovyeFj8qeT5GYzR5aA6oO6JMOQM419mWYZS53yDg",
    "expiresAt": "2026-06-02T02:56:13.000Z"
  }
}
```

**SDK Code**

```python Success
import requests

url = "https://api-gateway-stg.transak.com/api/v2/transaction-session"

payload = {
    "quoteId": "",
    "walletAddress": "",
    "successUrl": "",
    "failureUrl": "",
    "config": {
        "colorMode": "DARK",
        "borderRadius": "8px",
        "height": "48px"
    }
}
headers = {
    "x-api-key": "",
    "x-user-ip": "",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript Success
const url = 'https://api-gateway-stg.transak.com/api/v2/transaction-session';
const options = {
  method: 'POST',
  headers: {'x-api-key': '', 'x-user-ip': '', 'Content-Type': 'application/json'},
  body: '{"quoteId":"","walletAddress":"","successUrl":"","failureUrl":"","config":{"colorMode":"DARK","borderRadius":"8px","height":"48px"}}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Success
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api-gateway-stg.transak.com/api/v2/transaction-session"

	payload := strings.NewReader("{\n  \"quoteId\": \"\",\n  \"walletAddress\": \"\",\n  \"successUrl\": \"\",\n  \"failureUrl\": \"\",\n  \"config\": {\n    \"colorMode\": \"DARK\",\n    \"borderRadius\": \"8px\",\n    \"height\": \"48px\"\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("x-api-key", "")
	req.Header.Add("x-user-ip", "")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Success
require 'uri'
require 'net/http'

url = URI("https://api-gateway-stg.transak.com/api/v2/transaction-session")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["x-api-key"] = ''
request["x-user-ip"] = ''
request["Content-Type"] = 'application/json'
request.body = "{\n  \"quoteId\": \"\",\n  \"walletAddress\": \"\",\n  \"successUrl\": \"\",\n  \"failureUrl\": \"\",\n  \"config\": {\n    \"colorMode\": \"DARK\",\n    \"borderRadius\": \"8px\",\n    \"height\": \"48px\"\n  }\n}"

response = http.request(request)
puts response.read_body
```

```java Success
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api-gateway-stg.transak.com/api/v2/transaction-session")
  .header("x-api-key", "")
  .header("x-user-ip", "")
  .header("Content-Type", "application/json")
  .body("{\n  \"quoteId\": \"\",\n  \"walletAddress\": \"\",\n  \"successUrl\": \"\",\n  \"failureUrl\": \"\",\n  \"config\": {\n    \"colorMode\": \"DARK\",\n    \"borderRadius\": \"8px\",\n    \"height\": \"48px\"\n  }\n}")
  .asString();
```

```php Success
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api-gateway-stg.transak.com/api/v2/transaction-session', [
  'body' => '{
  "quoteId": "",
  "walletAddress": "",
  "successUrl": "",
  "failureUrl": "",
  "config": {
    "colorMode": "DARK",
    "borderRadius": "8px",
    "height": "48px"
  }
}',
  'headers' => [
    'Content-Type' => 'application/json',
    'x-api-key' => '',
    'x-user-ip' => '',
  ],
]);

echo $response->getBody();
```

```csharp Success
using RestSharp;

var client = new RestClient("https://api-gateway-stg.transak.com/api/v2/transaction-session");
var request = new RestRequest(Method.POST);
request.AddHeader("x-api-key", "");
request.AddHeader("x-user-ip", "");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"quoteId\": \"\",\n  \"walletAddress\": \"\",\n  \"successUrl\": \"\",\n  \"failureUrl\": \"\",\n  \"config\": {\n    \"colorMode\": \"DARK\",\n    \"borderRadius\": \"8px\",\n    \"height\": \"48px\"\n  }\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Success
import Foundation

let headers = [
  "x-api-key": "",
  "x-user-ip": "",
  "Content-Type": "application/json"
]
let parameters = [
  "quoteId": "",
  "walletAddress": "",
  "successUrl": "",
  "failureUrl": "",
  "config": [
    "colorMode": "DARK",
    "borderRadius": "8px",
    "height": "48px"
  ]
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api-gateway-stg.transak.com/api/v2/transaction-session")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```