App Engine standard environment for Python 3 release notes

You can migrate your App Engine push queues to Cloud Tasks by updating the bundled services SDK. This method lets you upgrade your app without needing to modify your application code. For more information on how to migrate, see the push queues migration guide (Preview).

Support for migrating from the App Engine Images service to Cloud Run is in General Availability (GA).

To improve security, starting in August 2026, App Engine opts your application into TLS version 1.2 and later. You can opt out until the end of August 2026. Starting in September 2026, App Engine might permanently block insecure traffic with TLS version 1.1 and earlier. For more information, see Secure minimum TLS.

Support for enabling only needed legacy bundled services using the app_engine_bundled_services field is in General Availability.

To modernize image processing, migrate from the App Engine Images service to Cloud Run by routing calls to a Cloud Run image transformation service while your app continues to run on App Engine (Preview).

App Engine supports Direct VPC egress in Preview. Direct VPC egress lets your workloads access VPC network resources as a simpler, more cost-effective alternative to Serverless VPC Access connectors.

Enable only needed legacy bundled services using the app_engine_bundled_services field for improved security and maintainability of your applications (Preview).

The App Engine Migration hub lets you migrate services in the App Engine standard environment to Cloud Run, and also provides cost-saving recommendations. For more information, see Deploy an App Engine app in the standard environment to Cloud Run (Preview).

Support for migrating from the legacy Mail API to an SMTP-based email service, such as SendGrid, Mailgun, or Mailjet is in General Availability.

Support for deploying your existing apps in the standard environment to Cloud Run using the gcloud beta app migrate-to-run command is in Preview. For more information, see Deploy an App Engine app in the standard environment to Cloud Run.

Python 2.7 is deprecated. You won't be able to deploy Python 2.7 applications, even if your organization previously used an organization policy to re-enable deployments of legacy runtimes. Your existing Python 2.7 applications will continue to run and receive traffic. We recommend that you migrate to the latest supported version of Python.

Support for Python 3.14 runtime is in General Availability.

Support for Python 3.14 runtime is in Preview.

To improve email security and ensure reliable, high-volume email delivery, migrate from the legacy Mail API to an SMTP-based email service, such as SendGrid, Mailgun, or Mailjet (Preview).

Support for TLS version 1.2 and later, along with a corresponding secure set of cipher suites, is in General Availability (GA).

To increase security, starting in March 2025, support for Transport Layer Security (TLS) version 1.1 and earlier is deprecated. Update your application settings in the App Engine standard environment to use TLS version 1.2 and later, along with a corresponding secure set of cipher suites (Preview).

For new deployments, the URL Fetch API validates the certificate of the host it contacts by default.

Support for Python 3.13 runtime is in General Availability (GA).

Python 3.13 is now available in Preview.

Container Registry is now shut down. We recommend that you use Artifact Registry for storing and managing container images. By default, new deployments created after March 5, 2025, use Artifact Registry instead of Container Registry for storing application build images. For more information, see Migrate App Engine container images to Artifact Registry.

For new projects you create after March 2025, App Engine sets the automatic scaling maximum instances default for standard environment deployments to 20. This change doesn't impact existing apps. To override the default, specify a new max_instances value in your app.yaml file, and deploy a new version or redeploy over an existing version.

Custom organization policies for Serverless VPC Access connectors are now generally available, and can be applied to projects, folders, or organizations.

In the App Engine page in the Google Cloud console, you can now filter your existing App Engine versions by runtime lifecycle stages. After you apply this filter, the console displays a warning icon for App Engine versions that are approaching end of support, have reached end of support, are deprecated, and are decomissioned.

Deployments for new projects might be impacted from the following changes to org policies:

• Starting in May 2024, Google Cloud enforces secure-by-default organization policies for all organization resources. This policy prevents App Engine from granting the Editor role to the App Engine default services accounts by default.

• Starting in June 2024, Cloud Build has changed the default behavior for how Cloud Build uses service accounts in new projects. This change is detailed in Cloud Build Service Account Change. As a result of this change, new projects deploying versions for the first time may be using the default App Engine service account with insufficient permissions for deploying versions.

If you are impacted by this change you can do one of the following:

• Grant the Editor role to the App Engine default service account.

• Review the Cloud Build guidance on changes to the default service account and opt out of these changes.

You can't use the latest version of dev_appserver.py to locally run your applications for runtimes that reached end of support. To continue using an archived version of dev_appserver.py, see Use the local development server after runtimes reach the end of support.

Python 3.7 has reached end of support on January 30, 2024. Your existing Python 3.7 applications will continue to run and receive traffic. However, App Engine might block re-deployments of applications that use runtimes after their end of support date. We recommend that you migrate to the latest supported version of Python.

The option to update a Serverless VPC Access connector is now available at general availability (GA). This feature allows you to edit the machine (instance) type, as well as the minimum and maximum number of instances.

A warning message now appears before you publish a container image to a public repository.

Python 3.12 is now generally available.

Python 3.12 is now available in preview.

Accessing a service that's prohibited by the Internal or Internal and Cloud Load Balancing ingress setting now results in a 404 rather than 403 error code.

Memory limits for second-generation runtimes have been increased to better support the growing memory utilization of many newer runtimes.

The Search API is now available in the App Engine legacy bundled services for second-generation runtimes. Access this legacy bundled service through the App Engine services SDK for Python 3.

If you use the local development server to simulate an App Engine app in production, you must now run dev_appserver.py with Python 3 and set the CLOUDSDK_DEVAPPSERVER_PYTHON environment variable in your shell to the path of your Python 2 interpreter. Learn more about the required setup steps.

The Python 3.11 runtime for App Engine standard environment is now generally available.

The Python 3.11 runtime for App Engine standard environment is now available in preview.

The option to update a Serverless VPC Access connector is now available in preview. This feature allows you to edit the machine (instance) type, as well as the minimum and maximum number of instances.

You can now use any configured service account in your Cloud project as the app-level default service account, while creating and updating your App Engine applications.

Build environment variables support is now generally available.

The Python 3.10 runtime for App Engine standard environment is now generally available.

The Python 3.10 runtime (preview) now uses Ubuntu 22.

Specifying a user-managed service account for each App Engine version during deployment is now generally available.

The Python 3.10 runtime for App Engine standard environment is now available in Preview.

The App Engine legacy bundled services for Python 3 are now available at the General Availability release level. These APIs can be accessed through language-idiomatic libraries. Calls to these API are billed according to the standard rates.

Support for Serverless VPC Access connectors in Shared VPC host projects is now at general availability (GA). Learn about the advantages of this method and how to configure connectors in host projects.