Sleep within a workflow for a given duration or until a specific date. This is a durable sleep that persists across workflow suspensions and resumptions.
Signature
function sleep(duration: StringValue): Promise<void>
function sleep(date: Date): Promise<void>
function sleep(durationMs: number): Promise<void>
Parameters
A duration string in the format of "1000ms", "1s", "1m", "1h", or "1d".
A Date object representing when to resume. Must be a future date.
The duration to sleep for in milliseconds.
Returns
A promise that resolves when the sleep duration has elapsed.
Usage
Sleep with Duration String
Pause for a human-readable duration:
import { sleep } from 'workflow';
export async function workflowWithSleep() {
"use workflow";
console.log('Starting...');
await sleep('5s');
console.log('After 5 seconds');
await sleep('2m');
console.log('After 2 minutes');
await sleep('1h');
console.log('After 1 hour');
await sleep('1d');
console.log('After 1 day');
}
Sleep with Milliseconds
Pause for a specific number of milliseconds:
import { sleep } from 'workflow';
export async function workflowWithMsSleep() {
"use workflow";
console.log('Starting...');
await sleep(5000); // 5 seconds
console.log('After 5000ms');
await sleep(60000); // 1 minute
console.log('After 60000ms');
}
Sleep Until Specific Date
Pause until a specific point in time:
import { sleep } from 'workflow';
export async function workflowWithDateSleep() {
"use workflow";
const tomorrow = new Date();
tomorrow.setDate(tomorrow.getDate() + 1);
tomorrow.setHours(9, 0, 0, 0); // 9 AM tomorrow
console.log('Sleeping until:', tomorrow);
await sleep(tomorrow);
console.log('Good morning!');
}
Retry Pattern
Implement exponential backoff:
import { sleep } from 'workflow';
export async function workflowWithRetry() {
"use workflow";
let attempt = 0;
const maxAttempts = 5;
while (attempt < maxAttempts) {
try {
await processData();
break;
} catch (error) {
attempt++;
if (attempt < maxAttempts) {
const delay = Math.pow(2, attempt) * 1000; // Exponential backoff
console.log(`Attempt ${attempt} failed, retrying in ${delay}ms`);
await sleep(delay);
}
}
}
}
Schedule Future Task
Schedule work for a specific time:
import { sleep } from 'workflow';
export async function scheduledWorkflow(scheduledTime: Date) {
"use workflow";
console.log('Waiting for scheduled time:', scheduledTime);
await sleep(scheduledTime);
console.log('Executing scheduled task');
await executeTask();
}
Polling with Delays
Poll an external system with delays:
import { sleep } from 'workflow';
export async function pollingWorkflow() {
"use workflow";
let status = 'pending';
while (status === 'pending') {
status = await checkStatus();
console.log('Status:', status);
if (status === 'pending') {
await sleep('30s'); // Poll every 30 seconds
}
}
console.log('Final status:', status);
}
Rate Limiting
Control the rate of operations:
import { sleep } from 'workflow';
export async function rateLimitedWorkflow(items: string[]) {
"use workflow";
for (const item of items) {
await processItem(item);
await sleep('1s'); // Rate limit to 1 item per second
}
}
"1000ms" - Milliseconds"1s" - Seconds"1m" - Minutes"1h" - Hours"1d" - Days
You can also combine units: "1h 30m", "2d 3h", etc.
Notes
- Can only be called inside a workflow function (with
"use workflow")
- This is a durable sleep that persists across workflow suspensions
- The workflow will be suspended during sleep and resumed when the duration elapses
- Sleep uses timer events in the event log for durability
- When sleeping until a date, the date must be in the future
- Very long sleep durations (months/years) are supported