The success value type of the effect
The error type of the effect
The effect to execute. Must have all dependencies satisfied (never).
Optionalsignal: AbortSignalAn optional AbortSignal used to cancel the running effect
Optionalctx: Record<string, unknown>A Promise that resolves with the effect's success value
This is the only way to "escape" the Effect system and obtain a concrete value. An optional AbortSignal can be passed to support cancellation — when the signal is aborted, the abort propagates to every running thunk created by fn.
All dependencies required by the effect must be provided (via
Dependency.provide) before calling run; otherwise the effect
will reject with Error("Missing dependency: <tag>").
Executes an Effect and returns a
Promisethat resolves with the success value or rejects with the error.