Overcast is alpha — behaviour and APIs may change between releases. Pin your version and read the changelog before upgrading.

overcast

documentation

Start here, go deeper if you need to.

Run the container, point your tooling at localhost:4566, and check the support matrix for gaps.

>_ start overcast 
docker run --rm \
  -p 4566:4566 \
  -p 4567:4567 \
  ghcr.io/overcast-sh/overcast:latest

Common first steps

Using AWS SDKs and CLI with Overcast

Pointing the AWS CLI, Node.js, Python, Go, Java, .NET, Rust and Terraform at Overcast, plus overcast env and overcast aws, S3 addressing styles, and the credential and region defaults.
Using AWS CDK with Overcast

Bootstrap and deploy a CDK stack against Overcast: the environment CDK needs, the five calls a deploy makes, and where the resource coverage, limitations and fixes live.
Migrating from LocalStack

Swap the image line and keep the rest: the compose diff, the endpoint and hostname settings, and where the variable, endpoint and behavioural detail lives.

Build against it

You have it running and you are writing the app.

Run and operate it

You are the one who has to keep it up.

Reference

Tables, for looking one thing up.

Support matrix

Every service and operation, with the gaps marked.
LocalStack compatibility matrix

LocalStack ports, hostnames, container conventions and client tools, each with its status.

Reference index

Emulation tiers, the service index, event pipelines, and the console.

Alpha stability

Any release may change behaviour, config, or APIs.

  • Pin an exact tag: ghcr.io/overcast-sh/overcast:0.0.1-alpha.NN. Both :latest and :alpha move with every release.
  • Check the release changelog before upgrading.
  • Report anything unexpected on GitHub.