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Namespace: workflow

This library provides tools required for authoring workflows.

Usage

See the tutorial for writing your first workflow.

Timers

The recommended way of scheduling timers is by using the sleep function. We've replaced setTimeout and clearTimeout with deterministic versions so these are also usable but have a limitation that they don't play well with cancellation scopes.

import { sleep } from '@temporalio/workflow';

export async function sleeper(ms = 100): Promise<void> {
await sleep(ms);
console.log('slept');
}

Activities

To schedule Activities, use proxyActivities to obtain an Activity function and call.

import { proxyActivities } from '@temporalio/workflow';
import type * as activities from '../activities';

const { httpGet } = proxyActivities<typeof activities>({
startToCloseTimeout: '1 minute',
});

export async function http(): Promise<string> {
return await httpGet('https://temporal.io');
}

Signals and Queries

To add signal handlers to a Workflow, add a signals property to the exported workflow object. Signal handlers can return either void or Promise<void>, you may schedule activities and timers from a signal handler.

To add query handlers to a Workflow, add a queries property to the exported workflow object. Query handlers must not mutate any variables or generate any commands (like Activities or Timers), they run synchronously and thus must return a Promise.

Implementation

import { CancelledFailure, defineQuery, setHandler, condition } from '@temporalio/workflow';
import { unblockSignal } from './definitions';

export const isBlockedQuery = defineQuery<boolean>('isBlocked');

export async function unblockOrCancel(): Promise<void> {
let isBlocked = true;
setHandler(unblockSignal, () => void (isBlocked = false));
setHandler(isBlockedQuery, () => isBlocked);
try {
console.log('Blocked');
await condition(() => !isBlocked);
isBlocked = false;
console.log('Unblocked');
} catch (err) {
if (!(err instanceof CancelledFailure)) {
throw err;
}
console.log('Cancelled');
}
}

Deterministic built-ins

It is safe to call Math.random() and Date() in workflow code as they are replaced with deterministic versions. We also provide a deterministic uuid4 function for convenience.

Cancellation and scopes

Sinks

Enumerations

Classes

Interfaces

References

ActivityCancellationType

Re-exports ActivityCancellationType


ActivityFailure

Re-exports ActivityFailure


ActivityFunction

Re-exports ActivityFunction


ActivityInterface

Re-exports ActivityInterface


ActivityOptions

Re-exports ActivityOptions


ApplicationFailure

Re-exports ApplicationFailure


CancelledFailure

Re-exports CancelledFailure


ChildWorkflowFailure

Re-exports ChildWorkflowFailure


Headers

Re-exports Headers


Next

Re-exports Next


PayloadConverter

Re-exports PayloadConverter


RetryPolicy

Re-exports RetryPolicy


ServerFailure

Re-exports ServerFailure


TemporalFailure

Re-exports TemporalFailure


TerminatedFailure

Re-exports TerminatedFailure


TimeoutFailure

Re-exports TimeoutFailure


defaultPayloadConverter

Re-exports defaultPayloadConverter


rootCause

Re-exports rootCause

Type aliases

CommonWorkflowOptions

Ƭ CommonWorkflowOptions: BaseWorkflowOptions & WorkflowDurationOptions


ConcludeActivationOutput

Ƭ ConcludeActivationOutput: ConcludeActivationInput

Output for WorkflowInternalsInterceptor.concludeActivation


ContinueAsNewInputOptions

Ƭ ContinueAsNewInputOptions: ContinueAsNewOptions & Required<Pick<ContinueAsNewOptions, "workflowType">>

Same as ContinueAsNewOptions but workflowType must be defined


Handler

Ƭ Handler<Ret, Args, T>: T extends SignalDefinition<infer A> ? (...args: A) => void | Promise<void> : T extends QueryDefinition<infer R, infer A> ? (...args: A) => R : never

A handler function capable of accepting the arguments for a given SignalDefinition or QueryDefinition.

Type parameters

NameType
RetRet
Argsextends any[]
Textends SignalDefinition<Args> | QueryDefinition<Ret, Args>

InternalActivityFunction

Ƭ InternalActivityFunction<P, R>: ActivityFunction<P, R> & ActivityInfo

Type parameters

NameType
Pextends any[]
RR

Payload

Ƭ Payload: IPayload


SearchAttributeValue

Ƭ SearchAttributeValue: string[] | number[] | boolean[] | Date[]


SearchAttributes

Ƭ SearchAttributes: Record<string, SearchAttributeValue | undefined>

If another SDK creates a Search Attribute that's not an array, we wrap it in an array.

Dates are serialized as ISO strings.


Sink

Ƭ Sink: Record<string, SinkFunction>

A mapping of name to function, defines a single sink (e.g. logger)


SinkFunction

Ƭ SinkFunction: (...args: any[]) => void

Type declaration

▸ (...args): void

Any function signature can be used for Sink functions as long as the return type is void.

When calling a Sink function, arguments are copied from the Workflow isolate to the Node.js environment using postMessage.

This constrains the argument types to primitives (excluding Symbols).

Parameters
NameType
...argsany[]
Returns

void


Sinks

Ƭ Sinks: Record<string, Sink>

Workflow Sink are a mapping of name to Sink


WithCompiledWorkflowOptions

Ƭ WithCompiledWorkflowOptions<T>: Replace<T, { workflowExecutionTimeout?: IDuration ; workflowRunTimeout?: IDuration ; workflowTaskTimeout?: IDuration }>

Type parameters

NameType
Textends CommonWorkflowOptions

WithWorkflowArgs

Ƭ WithWorkflowArgs<W, T>: T & Parameters<W> extends [any, ...any[]] ? { args: Parameters<W> } : { args?: Parameters<W> }

Type parameters

NameType
Wextends Workflow
TT

Workflow

Ƭ Workflow: (...args: any[]) => WorkflowReturnType

Type declaration

▸ (...args): WorkflowReturnType

Broad Workflow function definition, specific Workflows will typically use a narrower type definition, e.g:

export async function myWorkflow(arg1: number, arg2: string): Promise<string>;
Parameters
NameType
...argsany[]
Returns

WorkflowReturnType


WorkflowInterceptorsFactory

Ƭ WorkflowInterceptorsFactory: () => WorkflowInterceptors

Type declaration

▸ (): WorkflowInterceptors

A function that returns WorkflowInterceptors and takes no arguments.

Workflow interceptor modules should export an interceptors function of this type.

example

export function interceptors(): WorkflowInterceptors {
return {
inbound: [], // Populate with list of interceptor implementations
outbound: [], // Populate with list of interceptor implementations
internals: [], // Populate with list of interceptor implementations
};
}
Returns

WorkflowInterceptors


WorkflowQueryType

Ƭ WorkflowQueryType: (...args: any[]) => any

Type declaration

▸ (...args): any

Parameters
NameType
...argsany[]
Returns

any


WorkflowResultType

Ƭ WorkflowResultType<W>: ReturnType<W> extends Promise<infer R> ? R : never

Get the "unwrapped" return type (without Promise) of the execute handler from Workflow type W

Type parameters

NameType
Wextends Workflow

WorkflowReturnType

Ƭ WorkflowReturnType: Promise<any>

Type that can be returned from a Workflow execute function


WorkflowSignalType

Ƭ WorkflowSignalType: (...args: any[]) => Promise<void> | void

Type declaration

▸ (...args): Promise<void> | void

Parameters
NameType
...argsany[]
Returns

Promise<void> | void

Variables

AsyncLocalStorage

Const AsyncLocalStorage: <T>() => ALS<T>

Type declaration

• <T>()

Type parameters
Name
T

ROOT_SCOPE

Const ROOT_SCOPE: RootCancellationScope

There can only be one of these


stackTraceQuery

Const stackTraceQuery: QueryDefinition<string, []>

Functions

addDefaultWorkflowOptions

addDefaultWorkflowOptions<T>(opts): ChildWorkflowOptionsWithDefaults

Adds default values to workflowId and workflowIdReusePolicy to given workflow options.

Type parameters

NameType
Textends Workflow

Parameters

NameType
optsWithWorkflowArgs<T, ChildWorkflowOptions>

Returns

ChildWorkflowOptionsWithDefaults


compileWorkflowOptions

compileWorkflowOptions<T>(options): WithCompiledWorkflowOptions<T>

Type parameters

NameType
Textends CommonWorkflowOptions

Parameters

NameType
optionsT

Returns

WithCompiledWorkflowOptions<T>


condition

condition(fn, timeout): Promise<boolean>

Returns a Promise that resolves when fn evaluates to true or timeout expires.

Parameters

NameTypeDescription
fn() => boolean-
timeoutstring | numberms formatted string or number of milliseconds

Returns

Promise<boolean>

a boolean indicating whether the condition was true before the timeout expires

condition(fn): Promise<void>

Returns a Promise that resolves when fn evaluates to true.

Parameters

NameType
fn() => boolean

Returns

Promise<void>


continueAsNew

continueAsNew<F>(...args): Promise<never>

Continues current Workflow execution as new with default options.

Shorthand for makeContinueAsNewFunc<F>()(...args).

example

import { continueAsNew } from '@temporalio/workflow';

export function myWorkflow(n: number) {
return {
async execute() {
// ... Workflow logic
await continueAsNew<typeof myWorkflow>(n + 1);
}
};
}

Type parameters

NameType
Fextends Workflow

Parameters

NameType
...argsParameters<F>

Returns

Promise<never>


defineQuery

defineQuery<Ret, Args>(name): QueryDefinition<Ret, Args>

Define a query method for a Workflow.

Definitions are used to register handler in the Workflow via setHandler and to query Workflows using a WorkflowHandle. Definitions can be reused in multiple Workflows.

Type parameters

NameType
RetRet
Argsextends any[] = []

Parameters

NameType
namestring

Returns

QueryDefinition<Ret, Args>


defineSignal

defineSignal<Args>(name): SignalDefinition<Args>

Define a signal method for a Workflow.

Definitions are used to register handler in the Workflow via setHandler and to signal Workflows using a WorkflowHandle, ChildWorkflowHandle or ExternalWorkflowHandle. Definitions can be reused in multiple Workflows.

Type parameters

NameType
Argsextends any[] = []

Parameters

NameType
namestring

Returns

SignalDefinition<Args>


deprecatePatch

deprecatePatch(patchId): void

Indicate that a patch is being phased out.

See docs page for info.

Workflows with this call may be deployed alongside workflows with a patched call, but they must not be deployed while any workers still exist running old code without a patched call, or any runs with histories produced by such workers exist. If either kind of worker encounters a history produced by the other, their behavior is undefined.

Once all live workflow runs have been produced by workers with this call, you can deploy workers which are free of either kind of patch call for this ID. Workers with and without this call may coexist, as long as they are both running the "new" code.

Parameters

NameTypeDescription
patchIdstringAn identifier that should be unique to this patch. It is OK to use multiple calls with the same ID, which means all such calls will always return the same value.

Returns

void


errorCode

errorCode(error): string | undefined

Get error code from an Error or return undefined

Parameters

NameType
errorunknown

Returns

string | undefined


errorMessage

errorMessage(err): string | undefined

Get error message from an Error or string or return undefined

Parameters

NameType
errunknown

Returns

string | undefined


executeChild

executeChild<T>(workflowType, options): Promise<WorkflowResultType<T>>

Start a child Workflow execution and await its completion.

  • By default, a child will be scheduled on the same task queue as its parent.
  • This operation is cancellable using CancellationScopes.

Type parameters

NameType
Textends Workflow

Parameters

NameType
workflowTypestring
optionsWithWorkflowArgs<T, ChildWorkflowOptions>

Returns

Promise<WorkflowResultType<T>>

The result of the child Workflow.

executeChild<T>(workflowType, options): Promise<WorkflowResultType<T>>

Start a child Workflow execution and await its completion.

  • By default, a child will be scheduled on the same task queue as its parent.
  • Deduces the Workflow type and signature from provided Workflow function.
  • This operation is cancellable using CancellationScopes.

Type parameters

NameType
Textends Workflow

Parameters

NameType
workflowTypeT
optionsWithWorkflowArgs<T, ChildWorkflowOptions>

Returns

Promise<WorkflowResultType<T>>

The result of the child Workflow.

executeChild<T>(workflowType): Promise<WorkflowResultType<T>>

Start a child Workflow execution and await its completion.

Override for Workflows that accept no arguments.

  • The child will be scheduled on the same task queue as its parent.
  • This operation is cancellable using CancellationScopes.

Type parameters

NameType
Textends () => WorkflowReturnType

Parameters

NameType
workflowTypestring

Returns

Promise<WorkflowResultType<T>>

The result of the child Workflow.

executeChild<T>(workflowFunc): Promise<WorkflowResultType<T>>

Start a child Workflow execution and await its completion.

Override for Workflows that accept no arguments.

  • The child will be scheduled on the same task queue as its parent.
  • Deduces the Workflow type and signature from provided Workflow function.
  • This operation is cancellable using CancellationScopes.

Type parameters

NameType
Textends () => WorkflowReturnType

Parameters

NameType
workflowFuncT

Returns

Promise<WorkflowResultType<T>>

The result of the child Workflow.


getExternalWorkflowHandle

getExternalWorkflowHandle(workflowId, runId?): ExternalWorkflowHandle

Returns a client-side handle that can be used to signal and cancel an existing Workflow execution. It takes a Workflow ID and optional run ID.

Parameters

NameType
workflowIdstring
runId?string

Returns

ExternalWorkflowHandle


inWorkflowContext

inWorkflowContext(): boolean

Returns whether or not code is executing in workflow context

Returns

boolean


isCancellation

isCancellation(err): boolean

Returns whether provided err is caused by cancellation

Parameters

NameType
errunknown

Returns

boolean


makeContinueAsNewFunc

makeContinueAsNewFunc<F>(options?): (...args: Parameters<F>) => Promise<never>

Returns a function f that will cause the current Workflow to ContinueAsNew when called.

f takes the same arguments as the Workflow execute function supplied to typeparam F.

Once f is called, Workflow execution immediately completes.

Type parameters

NameType
Fextends Workflow

Parameters

NameType
options?ContinueAsNewOptions

Returns

fn

▸ (...args): Promise<never>

Returns a function f that will cause the current Workflow to ContinueAsNew when called.

f takes the same arguments as the Workflow execute function supplied to typeparam F.

Once f is called, Workflow execution immediately completes.

Parameters
NameType
...argsParameters<F>
Returns

Promise<never>


patched

patched(patchId): boolean

Patch or upgrade workflow code by checking or stating that this workflow has a certain patch.

See docs page for info.

If the workflow is replaying an existing history, then this function returns true if that history was produced by a worker which also had a patched call with the same patchId. If the history was produced by a worker without such a call, then it will return false.

If the workflow is not currently replaying, then this call always returns true.

Your workflow code should run the "new" code if this returns true, if it returns false, you should run the "old" code. By doing this, you can maintain determinism.

Parameters

NameTypeDescription
patchIdstringAn identifier that should be unique to this patch. It is OK to use multiple calls with the same ID, which means all such calls will always return the same value.

Returns

boolean


proxyActivities

proxyActivities<A>(options): A

Configure Activity functions with given ActivityOptions.

This method may be called multiple times to setup Activities with different options.

example

import { proxyActivities, ActivityInterface } from '@temporalio/workflow';
import * as activities from '../activities';

// Setup Activities from module exports
const { httpGet, otherActivity } = proxyActivities<typeof activities>({
startToCloseTimeout: '30 minutes',
});

// Setup Activities from an explicit interface (e.g. when defined by another SDK)
interface JavaActivities extends ActivityInterface {
httpGetFromJava(url: string): Promise<string>
someOtherJavaActivity(arg1: number, arg2: string): Promise<string>;
}

const {
httpGetFromJava,
someOtherJavaActivity
} = proxyActivities<JavaActivities>({
taskQueue: 'java-worker-taskQueue',
startToCloseTimeout: '5m',
});

export function execute(): Promise<void> {
const response = await httpGet('http://example.com');
// ...
}

Type parameters

NameTypeDescription
Aextends ActivityInterfaceAn ActivityInterface - mapping of name to function

Parameters

NameType
optionsActivityOptions

Returns

A

a Proxy for which each attribute is a callable Activity function


proxyLocalActivities

proxyLocalActivities<A>(options): A

Configure Local Activity functions with given LocalActivityOptions.

This method may be called multiple times to setup Activities with different options.

experimental

See proxyActivities for examples

Type parameters

NameTypeDescription
Aextends ActivityInterfaceAn ActivityInterface - mapping of name to function

Parameters

NameType
optionsLocalActivityOptions

Returns

A

a Proxy for which each attribute is a callable Activity function


proxySinks

proxySinks<T>(): T

Get a reference to Sinks for exporting data out of the Workflow.

These Sinks must be registered with the Worker in order for this mechanism to work.

example

import { proxySinks, Sinks } from '@temporalio/workflow';

interface MySinks extends Sinks {
logger: {
info(message: string): void;
error(message: string): void;
};
}

const { logger } = proxySinks<MyDependencies>();
logger.info('setting up');

export function myWorkflow() {
return {
async execute() {
logger.info('hey ho');
logger.error('lets go');
}
};
}

Type parameters

NameType
Textends Sinks

Returns

T


setHandler

setHandler<Ret, Args, T>(def, handler): void

Set a handler function for a Workflow query or signal.

If this function is called multiple times for a given signal or query name the last handler will overwrite any previous calls.

Type parameters

NameType
RetRet
Argsextends any[]
Textends SignalDefinition<Args> | QueryDefinition<Ret, Args>

Parameters

NameTypeDescription
defTa SignalDefinition or QueryDefinition as returned by defineSignal or defineQuery respectively.
handlerundefined | Handler<Ret, Args, T>a compatible handler function for the given definition or undefined to unset the handler.

Returns

void


sleep

sleep(ms): Promise<void>

Asynchronous sleep.

Schedules a timer on the Temporal service.

Parameters

NameTypeDescription
msstring | numbersleep duration - ms formatted string or number of milliseconds. If given a negative number or 0, value will be set to 1.

Returns

Promise<void>


startChild

startChild<T>(workflowType, options): Promise<ChildWorkflowHandle<T>>

Start a child Workflow execution

  • Returns a client-side handle that implements a child Workflow interface.
  • By default, a child will be scheduled on the same task queue as its parent.

A child Workflow handle supports awaiting completion, signaling and cancellation via CancellationScopes. In order to query the child, use a WorkflowClient from an Activity.

Type parameters

NameType
Textends Workflow

Parameters

NameType
workflowTypestring
optionsWithWorkflowArgs<T, ChildWorkflowOptions>

Returns

Promise<ChildWorkflowHandle<T>>

startChild<T>(workflowFunc, options): Promise<ChildWorkflowHandle<T>>

Start a child Workflow execution

  • Returns a client-side handle that implements a child Workflow interface.
  • Deduces the Workflow type and signature from provided Workflow function.
  • By default, a child will be scheduled on the same task queue as its parent.

A child Workflow handle supports awaiting completion, signaling and cancellation via CancellationScopes. In order to query the child, use a WorkflowClient from an Activity.

Type parameters

NameType
Textends Workflow

Parameters

NameType
workflowFuncT
optionsWithWorkflowArgs<T, ChildWorkflowOptions>

Returns

Promise<ChildWorkflowHandle<T>>

startChild<T>(workflowType): Promise<ChildWorkflowHandle<T>>

Start a child Workflow execution

Override for Workflows that accept no arguments.

  • Returns a client-side handle that implements a child Workflow interface.
  • The child will be scheduled on the same task queue as its parent.

A child Workflow handle supports awaiting completion, signaling and cancellation via CancellationScopes. In order to query the child, use a WorkflowClient from an Activity.

Type parameters

NameType
Textends () => Promise<any>

Parameters

NameType
workflowTypestring

Returns

Promise<ChildWorkflowHandle<T>>

startChild<T>(workflowFunc): Promise<ChildWorkflowHandle<T>>

Start a child Workflow execution

Override for Workflows that accept no arguments.

  • Returns a client-side handle that implements a child Workflow interface.
  • Deduces the Workflow type and signature from provided Workflow function.
  • The child will be scheduled on the same task queue as its parent.

A child Workflow handle supports awaiting completion, signaling and cancellation via CancellationScopes. In order to query the child, use a WorkflowClient from an Activity.

Type parameters

NameType
Textends () => Promise<any>

Parameters

NameType
workflowFuncT

Returns

Promise<ChildWorkflowHandle<T>>


taskInfo

taskInfo(): TaskInfo

Get information about the currently executing Workflow Task.

See TaskInfo

Returns

TaskInfo


upsertSearchAttributes

upsertSearchAttributes(searchAttributes): void

Updates this Workflow's Search Attributes by merging the provided searchAttributes with the existing Search Attributes, workflowInfo().searchAttributes.

For example, this Workflow code:

upsertSearchAttributes({
CustomIntField: [1, 2, 3],
CustomBoolField: [true]
});
upsertSearchAttributes({
CustomIntField: [42],
CustomKeywordField: ['durable code', 'is great']
});

would result in the Workflow having these Search Attributes:

{
CustomIntField: [42],
CustomBoolField: [true],
CustomKeywordField: ['durable code', 'is great']
}

Parameters

NameTypeDescription
searchAttributesSearchAttributesThe Record to merge. Use a value of [] to clear a Search Attribute.

Returns

void


uuid4

uuid4(): string

Generate an RFC compliant V4 uuid. Uses the workflow's deterministic PRNG making it safe for use within a workflow. This function is cryptographically insecure. See the stackoverflow discussion.

Returns

string


workflowInfo

workflowInfo(): WorkflowInfo

Get information about the current Workflow

Returns

WorkflowInfo