Effect-TS Has a Free API: TypeScript's Missing Standard Library

TypeScript has great types but no standard library for error handling, concurrency, or dependency injection. Effect fixes all three. What Is Effect? Effect is a TypeScript library that gives you typed errors, structured concurrency, dependency injection, retries, timeouts, and more — all composable and type-safe. import { Effect , Console } from " effect " const program = Effect . gen ( function * () { yield * Console . log ( " Hello from Effect! " ) const result = yield * Effect . succeed ( 42 ) yield * Console . log ( \ `The answer is \$ {result} \` ) return result }) Effect.runPromise(program) Typed Errors: No More Try-Catch Guessing import { Effect , Data } from " effect " class UserNotFound extends Data . TaggedError ( " UserNotFound " ) < { readonly userId : string } > {} class DatabaseError extends Data . TaggedError ( " DatabaseError " ) < { readonly message : string } > {} // The type signature TELLS you what can go wrong const getUser = ( id : string ): Effect . Effect < User