WorkflowEngine.ts

WorkflowEngine.ts overview

Defines workflow engine services and an in-memory implementation.

WorkflowEngine registers workflow handlers, runs executions, polls results, resumes suspended runs, executes activities, stores durable deferred results, and schedules durable clocks. WorkflowInstance holds the runtime state for one workflow run. The in-memory layer is useful for tests and local development.

Since v4.0.0

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Exports Grouped by Category

• Encoded
  • Encoded (interface)
• constructors
  • makeUnsafe
• layers
  • layerMemory
• services
  • WorkflowEngine (class)
  • WorkflowInstance (class)
    • initial (static method)

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Encoded

Encoded (interface)

Low-level workflow engine contract that works with encoded payloads and results before makeUnsafe adds typed schema decoding and encoding.

Signature

export interface Encoded {
  readonly register: (
    workflow: Workflow.Any,
    execute: (
      payload: object,
      executionId: string
    ) => Effect.Effect<unknown, unknown, WorkflowInstance | WorkflowEngine>
  ) => Effect.Effect<void, never, Scope.Scope>
  readonly execute: <const Discard extends boolean>(
    workflow: Workflow.Any,
    options: {
      readonly executionId: string
      readonly payload: object
      readonly discard: Discard
      readonly parent?: WorkflowInstance["Service"] | undefined
    }
  ) => Effect.Effect<Discard extends true ? void : Workflow.Result<unknown, unknown>>
  readonly poll: (
    workflow: Workflow.Any,
    executionId: string
  ) => Effect.Effect<Option.Option<Workflow.Result<unknown, unknown>>>
  readonly interrupt: (workflow: Workflow.Any, executionId: string) => Effect.Effect<void>
  readonly interruptUnsafe: (workflow: Workflow.Any, executionId: string) => Effect.Effect<void>
  readonly resume: (workflow: Workflow.Any, executionId: string) => Effect.Effect<void>
  readonly activityExecute: (
    activity: Activity.Any,
    attempt: number
  ) => Effect.Effect<Workflow.Result<unknown, unknown>, never, WorkflowInstance>
  readonly deferredResult: (
    deferred: DurableDeferred.Any
  ) => Effect.Effect<Option.Option<Exit.Exit<unknown, unknown>>, never, WorkflowInstance>
  readonly deferredDone: (options: {
    readonly workflowName: string
    readonly executionId: string
    readonly deferredName: string
    readonly exit: Exit.Exit<unknown, unknown>
  }) => Effect.Effect<void>
  readonly scheduleClock: (
    workflow: Workflow.Any,
    options: {
      readonly executionId: string
      readonly clock: DurableClock
    }
  ) => Effect.Effect<void>
}

Source

Since v4.0.0

constructors

makeUnsafe

Builds a typed WorkflowEngine service from a low-level encoded implementation.

When to use

Use when wiring a trusted low-level workflow engine implementation into the typed WorkflowEngine service.

Gotchas

The implementation must correctly persist, resume, and encode workflow state.

Signature

declare const makeUnsafe: (options: Encoded) => WorkflowEngine["Service"]

Source

Since v4.0.0

layers

layerMemory

Layer that provides an in-memory WorkflowEngine.

When to use

Use to run tests and local development workflows where durability is not needed.

Gotchas

This layer keeps state only in memory and is not suitable for production workflows that require durability.

Signature

declare const layerMemory: Layer.Layer<WorkflowEngine, never, never>

Source

Since v4.0.0

services

WorkflowEngine (class)

Service that represents workflow runtimes, responsible for registering and executing workflows and coordinating activities, durable deferreds, interrupts, resumes, and clocks.

Signature

declare class WorkflowEngine

Source

Since v4.0.0

WorkflowInstance (class)

Service that contains workflow runtime state for one execution.

When to use

Use to read or update workflow execution, suspension, interruption, lifetime, failure, and activity coordination state inside workflow engine internals.

Details

The service stores the execution ID, workflow definition, long-lived scope, suspension and interruption flags, the stored failure cause, and activity coordination state for a single workflow run.

Signature

declare class WorkflowInstance

Source

Since v4.0.0

initial (static method)

Signature

declare const initial: (workflow: Workflow.Any, executionId: string) => WorkflowInstance["Service"]

Source