The following list shows which services are supported in second-generation runtimes:
| App Engine service | Availability in Go | Alternatives | 
|---|---|---|
| App Identity | Available | Migrate to Open ID Connect (OIDC) or Identity Platform | 
| Datastore | Available | Migrate to Datastore client libraries or use the community-contributed datastorelibrary | 
| Available | Migrate to SendGrid, Mailgun, or Mailjet for outbound messaging only | |
| Memcache | Available | Migrate to Memorystore | 
| Modules | Available | Use environment variables and the App Engine Admin API to obtain information and modify your application's running services | 
| Remote | Not supported | Use Cloud Client Libraries to access resources in other projects | 
| Task Queues | Available | Migrate to Cloud Tasks for push queues | 
| URL Fetch | Available | Migrate to standard libraries for outbound requests | 
| Users | Available | Migrate to user authentication options | 
For more information, refer to the user guides located on the left-side navigation or see the API reference documentation.