interactive · effect v4
Effect playground
Edit, then Run. TypeScript and JavaScript execute in a Web Worker in this tab; Rust and Go compile on their official playgrounds. Default-export an Effect and the runner prints its value.
An Effect is a description of work — not a running Promise. Nothing happens until it's run. The playground runs whatever you export-default and prints its value. Change the return value, then Run.
Run the code to see console output and the result of the default-exported Effect.