Flow API Reference

Represents a value that may be returned directly or through a Promise.

Creates a branded failed result.

Failed `Result` variant.

Converts a structural result-like value into a branded Flow result.

Narrows a result to the failed variant.

Narrows a result to the successful variant.

Detects branded Flow results created by `ok`, `err`, or `from`.

Exhaustively handles both result variants and returns one value.

Creates a branded successful result.

Successful `Result` variant.

Explicit success-or-failure outcome used throughout Flow.

Namespace-style collection of core result helpers.

Structural result shape accepted by `from`.

Returns the success value or throws the error value.

Returns the success value or a fallback.

Aborts a controller only when it has not already been aborted.

Executable Flow workflow unit.

Extracts the custom context type from a behavior.

Extracts the expected domain error type from a behavior.

Extracts the input type from a behavior.

Extracts the output type from a behavior.

Creates a cancellation result.

Runtime error returned when execution is cancelled through an `AbortSignal`.

Replaces the signal on a runtime context.

Creates a child controller linked to a parent signal.

Defines a behavior from a callback that returns a `Result`.

Narrows an error value to `Cancelled`.

Narrows an error value to a Flow runtime error.

Narrows an error value to `Thrown`.

Links a parent signal to a child controller.

Converts an aborted signal into a cancellation result.

Runs a behavior with an optional application context.

Executes a behavior with runtime error protection.

Execution context passed to every behavior.

Runtime-level failure union added around every behavior's domain error type.

Creates a thrown-exception runtime result.

Runtime error returned when user code throws.

Aborts every tracked child controller.

Behavior shape accepted by keyed record helpers.

Object map of named behaviors for `all`, `allSettled`, and `race`.

Domain error returned when `race` is called with an empty behavior record.

Re-exports core result helpers used by advanced record internals.

Unions the expected domain error types of every behavior in a record.

Normalizes a requested concurrency value for keyed parallel helpers.

Re-exports core result helpers used by advanced record internals.

Maps each behavior key to its successful output type.

Keyed failure value returned by `race`.

Creates a keyed race failure payload.

Keyed success value returned by `race`.

Creates a keyed race success payload.

Intersects the custom context types of every behavior in a record.

Intersects the input types of every behavior in a record.

Runs a child behavior with a linked abort controller.

Maps each behavior key to the full result returned by that child.

Re-exports core result helpers used by advanced record internals.

Creates a behavior that always fails with the same domain error.

Creates an identity behavior for starting typed pipelines.

Maps the successful output of a behavior.

Composes behaviors from top to bottom.

Runs two behaviors left-to-right.

Creates a behavior that always succeeds with the same value.

Runs a side effect after source success without changing the output.

Creates a typed behavior from synchronous or asynchronous application code.

Runtime context provided to a `task` callback.

Return type accepted from a `task` callback.

Recovers one discriminated domain error variant by its `kind` field.

Maps expected domain errors without catching runtime errors.

Recovers expected domain failures into success or a new domain failure.

Waits before running a source behavior.

Retries a behavior when it returns an expected domain failure.

Configuration for retrying expected domain failures.

Runs one behavior execution with a timeout.

Wraps a behavior with a timeout.

Domain error returned when a timeout expires before source completion.

Timing-related errors added by timeout and delay helpers.

Waits for a duration while observing an `AbortSignal`.

Branches between two behaviors using a behavior predicate.

Branches between two behaviors using a predicate function.

Runs keyed behaviors in parallel and fails fast on the first child failure.

Runs keyed behaviors and collects every child result.

Runs keyed behaviors and returns the first settled child.