Custom runtimes allow for installing arbitrary packages and dependencies in the runtime of your workflow. Runtimes in floww are built on top of Docker images so they are fully customizable.
To use a custom runtime, you will have to create a Dockerfile that installs the dependencies you need.
When running npx floww deploy, the Dockerfile will automatically be built and used for the deployment.
Only include your dependencies (package.json) in the runtime, not your workflow code. Your workflow code is dynamically evaluated at runtime and should not be copied into the Docker image.
The Dockerfilewill be used when deploying the workflow but not when running floww locally.