Skip to main content

Interface: WorkflowHandle<T>

client.WorkflowHandle

A client side handle to a single Workflow instance. It can be used to start, signal, query, wait for completion, terminate and cancel a Workflow execution.

Given the following Workflow definition:

export const incrementSignal = defineSignal('increment');
export const getValueQuery = defineQuery<number>('getValue');
export async function counterWorkflow(initialValue: number): Promise<void>;

Create a handle for running and interacting with a single Workflow:

const client = new WorkflowClient();
// Start the Workflow with initialValue of 2.
const handle = await client.start({
workflowType: counterWorkflow,
args: [2],
taskQueue: 'tutorial',
});
await handle.signal(incrementSignal, 2);
await handle.query(getValueQuery); // 4
await handle.cancel();
await handle.result(); // throws WorkflowExecutionCancelledError

Type parameters

NameType
Textends Workflow = Workflow

Hierarchy

Properties

client

Readonly client: WorkflowClient

Readonly accessor to the underlying WorkflowClient


workflowId

Readonly workflowId: string

The workflowId of the current Workflow

Inherited from

BaseWorkflowHandle.workflowId

Methods

cancel

cancel(): Promise<IRequestCancelWorkflowExecutionResponse>

Cancel a running Workflow

Returns

Promise<IRequestCancelWorkflowExecutionResponse>


describe

describe(): Promise<WorkflowExecutionDescription>

Describe the current workflow execution

Returns

Promise<WorkflowExecutionDescription>


query

query<Ret, Args>(def, ...args): Promise<Ret>

Query a running or completed Workflow.

Example

await handle.query(getValueQuery);
await handle.query<number, []>('getValue');

Type parameters

NameType
RetRet
Argsextends any[] = []

Parameters

NameTypeDescription
defstring | QueryDefinition<Ret, Args>a query definition as returned from defineQuery or query name (string)
...argsArgs-

Returns

Promise<Ret>


result

result(): Promise<WorkflowResultType<T>>

Promise that resolves when Workflow execution completes

Returns

Promise<WorkflowResultType<T>>

Inherited from

BaseWorkflowHandle.result


signal

signal<Args>(def, ...args): Promise<void>

Signal a running Workflow.

Example

await handle.signal(incrementSignal, 3);

Type parameters

NameType
Argsextends any[] = []

Parameters

NameTypeDescription
defstring | SignalDefinition<Args>a signal definition as returned from defineSignal
...argsArgs-

Returns

Promise<void>

Inherited from

BaseWorkflowHandle.signal


terminate

terminate(reason?): Promise<ITerminateWorkflowExecutionResponse>

Terminate a running Workflow

Parameters

NameType
reason?string

Returns

Promise<ITerminateWorkflowExecutionResponse>