Editing Troubleshooting of Google Vertex AI Search (section)

=== Troubleshooting: SearchLite API Blocked" Error in Discovery Engine ===

'''Issue Description''': When attempting to retrieve search results using Google Vertex AI API<ref>[https://cloud.google.com/generative-ai-app-builder/docs/preview-search-results Get search results  |  Vertex AI Agent Builder  |  Google Cloud]</ref>, the following error occurs:

<pre>
curl -X POST -H "Content-Type: application/json" \
"https://discoveryengine.googleapis.com/v1/projects/PROJECT_ID/locations/global/collections/default_collection/engines/APP_ID/servingConfigs/default_search:searchLite?key=API_KEY" \
-d '{
"servingConfig": "projects/PROJECT_ID/locations/global/collections/default_collection/engines/APP_ID/servingConfigs/default_search",
"query": "QUERY",
}'
</pre>

Met the error
<pre>
{
  "code" : 403,
  "message" : "Requests to this API discoveryengine.googleapis.com method google.cloud.discoveryengine.v1.SearchService.SearchLite are blocked.",
  "status" : "PERMISSION_DENIED",
  "details" : [
    {
      "@type" : "type.googleapis.com/google.rpc.ErrorInfo",
      "reason" : "API_KEY_SERVICE_BLOCKED",
      "domain" : "googleapis.com",
      "metadata" : {
        "service" : "discoveryengine.googleapis.com",
        "methodName" : "google.cloud.discoveryengine.v1.SearchService.SearchLite",
        "apiName" : "discoveryengine.googleapis.com",
        "consumer" : "projects/xxx"
      }
    },
    {
      "@type" : "type.googleapis.com/google.rpc.LocalizedMessage",
      "locale" : "en-US",
      "message" : "Requests to this API discoveryengine.googleapis.com method google.cloud.discoveryengine.v1.SearchService.SearchLite are blocked."
    }
  ]
}
</pre>

'''Resolution Steps''': Check API Key Restrictions

* Verify if the key is restricted to specific APIs:
*# Navigate to the API Key Management page in Google Cloud Console.
*# Locate the API key being used and check if it is restricted to specific APIs. If the restriction includes discoveryengine.googleapis.com, ensure it is correctly configured.
*# Remove unnecessary restrictions: If the key is restricted to unrelated IP addresses or applications, remove those restrictions.
* Enable the {{kbd | key=Discovery Engine API}}
*# Go to the API & Services page in Google Cloud Console.
*# Search for Discovery Engine API and ensure it is enabled.