localstack / localstack/serverless-localstack

Support for Python 3.13 Lambdas

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Dominant language
JavaScript
Stars
542
Forks
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PR merge metrics
No merged PRs in 30d

Description

Context

AWS announced support for Python 3.13 runtime in November 2024. When attempting to deploy to Localstack, however, I get the following error:

      StackId: 'arn:aws:cloudformation:***:000000000000:stack/proj/00000',
      EventId: '137610ba-70c5-44f1-89a1-2a906c535d2d',
      StackName: 'business-analytics-serverless-local',
      LogicalResourceId: 'MyLambdaFunction',
      PhysicalResourceId: 'arn:aws:cloudformation:***:000000000000:stack/proj/00000',
      ResourceType: 'AWS::Lambda::Function',
      Timestamp: 2025-08-28T13:53:58.640Z,
      ResourceStatus: 'CREATE_FAILED',
      ResourceStatusReason: "An error occurred (InvalidParameterValueException) when calling the CreateFunction operation: Value python3.13 at 'runtime' failed to satisfy constraint: Member must satisfy enum value set: [nodejs20.x, provided.al2023, python3.12, java17, nodejs16.x, dotnet8, python3.10, java11, python3.11, dotnet6, java21, nodejs18.x, provided.al2, ruby3.3, java8.al2, ruby3.2, python3.8, python3.9] or be a valid ARN"
Expected Behavior

Successful deployment of Python 3.13 Lambdas.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the plugin's AWS Lambda runtime validation or resource deployment path and reproduce the reported Python 3.13 deployment failure. Done means a configuration using python3.13 is accepted and its Lambda deploys successfully against LocalStack.

Written by the indexing model from the issue text.

Assessment

Tech stack
aws, python
Domain
cloud
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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