Only require lwaRefreshToken when calling grantless operations

README.md

@@ -80,7 +80,7 @@ The array passed to the `Configuration` constructor accepts the following keys:
 
 * `lwaClientId (string)`: Required. The LWA client ID of the SP API application to use to execute API requests.
 * `lwaClientSecret (string)`: Required. The LWA client secret of the SP API application to use to execute API requests.
-* `lwaRefreshToken (string)`: Required. The LWA refresh token of the SP API application to use to execute API requests.
+* `lwaRefreshToken (string)`: The LWA refresh token of the SP API application to use to execute API requests. Required, unless you're only using the `Configuration` instance to call [grantless operations](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/en-US/developer-guide/SellingPartnerApiDeveloperGuide.md#grantless-operations).
 * `awsAccessKeyId (string)`: Required. AWS IAM user Access Key ID with SP API ExecuteAPI permissions.
 * `awsSecretAccessKey (string)`: Required. AWS IAM user Secret Access Key with SP API ExecuteAPI permissions.
 * `endpoint (array)`: Required. An array containing a `url` key (the endpoint URL) and a `region` key (the AWS region). There are predefined constants for these arrays in [`lib/Endpoint.php`](https://github.com/jlevers/selling-partner-api/blob/main/lib/Endpoint.php): (`NA`, `EU`, `FE`, and `NA_SANDBOX`, `EU_SANDBOX`, and `FE_SANDBOX`. See [here](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/en-US/developer-guide/SellingPartnerApiDeveloperGuide.md#selling-partner-api-endpoints) for more details.

lib/Authentication.php

@@ -17,7 +17,7 @@ class Authentication
 
     private $lwaClientId;
     private $lwaClientSecret;
-    private $refreshToken;
+    private $refreshToken = null;
     private $endpoint;
 
     private $onUpdateCreds;
@@ -50,7 +50,7 @@ public function __construct(array $configurationOptions)
     {
         $this->client = new Client();
 
-        $this->refreshToken = $configurationOptions['lwaRefreshToken'];
+        $this->refreshToken = $configurationOptions['lwaRefreshToken'] ?? null;
         $this->onUpdateCreds = $configurationOptions['onUpdateCredentials'];
         $this->lwaClientId = $configurationOptions['lwaClientId'];
         $this->lwaClientSecret = $configurationOptions['lwaClientSecret'];
@@ -72,7 +72,7 @@ public function __construct(array $configurationOptions)
     /**
      * @param string|null $scope
      * @return array
-     * @throws \GuzzleHttp\Exception\GuzzleException
+     * @throws \GuzzleHttp\Exception\GuzzleException|\RuntimeException
      */
     public function requestLWAToken(?string $scope = null): array
     {
@@ -87,6 +87,9 @@ public function requestLWAToken(?string $scope = null): array
         if ($scope !== null) {
             $jsonData["scope"] = $scope;
         } else {
+            if ($this->refreshToken === null) {
+                throw new RuntimeException('lwaRefreshToken must be specified when calling non-grantless API operations');
+            }
             $jsonData["refresh_token"] = $this->refreshToken;
         }
 

lib/Configuration.php

@@ -33,7 +33,7 @@ class Configuration
      * @const array[string]
      */
     public const REQUIRED_CONFIG_KEYS = [
-        "lwaClientId", "lwaClientSecret", "lwaRefreshToken", "awsAccessKeyId", "awsSecretAccessKey", "endpoint"
+        "lwaClientId", "lwaClientSecret", "awsAccessKeyId", "awsSecretAccessKey", "endpoint"
     ];
 
     /**