golem-recurring-task-ts

name	golem-recurring-task-ts
description	Implementing a recurring (cron-like) task in a TypeScript Golem agent by self-scheduling future invocations. Use when the user asks about periodic tasks, recurring jobs, cron-like scheduling, polling loops, heartbeats, or self-scheduling agents.

Recurring Tasks via Self-Scheduling (TypeScript)

Overview

A Golem agent can act as its own scheduler by calling .schedule() on itself at the end of each invocation. This creates a durable, crash-resilient recurring task — if the agent restarts, the scheduled invocation is still pending and will fire at the designated time.

Basic Pattern

The agent schedules its own method to run again after a delay:

import { agent, BaseAgent } from '@golemcloud/golem-ts-sdk';

@agent()
class PollerAgent extends BaseAgent {
    name: string;

    constructor(name: string) {
        super();
        this.name = name;
    }

    start(): void {
        this.poll();
    }

    poll(): void {
        // 1. Do the recurring work
        doWork();

        // 2. Schedule the next run (60 seconds from now)
        const self = PollerAgent.get(this.name);
        const nowSecs = BigInt(Math.floor(Date.now() / 1000));
        self.poll.schedule({ seconds: nowSecs + 60n, nanoseconds: 0 });
    }
}

Exponential Backoff

Increase the delay on repeated failures, reset on success:

@agent()
class PollerAgent extends BaseAgent {
    name: string;
    consecutiveFailures: number = 0;
    baseIntervalSecs: bigint = 60n;
    maxIntervalSecs: bigint = 3600n;

    constructor(name: string) {
        super();
        this.name = name;
    }

    poll(): void {
        const success = tryWork();

        let delay: bigint;
        if (success) {
            this.consecutiveFailures = 0;
            delay = this.baseIntervalSecs;
        } else {
            this.consecutiveFailures++;
            const exp = Math.min(this.consecutiveFailures, 6);
            delay = this.baseIntervalSecs * BigInt(2 ** exp);
            if (delay > this.maxIntervalSecs) delay = this.maxIntervalSecs;
        }

        const self = PollerAgent.get(this.name);
        const nowSecs = BigInt(Math.floor(Date.now() / 1000));
        self.poll.schedule({ seconds: nowSecs + delay, nanoseconds: 0 });
    }
}

Cancellation with CancellationToken

Every method on the generated client has a .scheduleCancelable() variant that returns a CancellationToken. Store the token and call .cancel() to prevent the scheduled invocation from firing:

import { CancellationToken } from '@golemcloud/golem-ts-sdk';

@agent()
class PollerAgent extends BaseAgent {
    name: string;
    cancelled: boolean = false;
    pendingToken: CancellationToken | undefined;

    constructor(name: string) {
        super();
        this.name = name;
    }

    poll(): void {
        if (this.cancelled) {
            return;
        }

        doWork();

        const self = PollerAgent.get(this.name);
        const nowSecs = BigInt(Math.floor(Date.now() / 1000));
        this.pendingToken = self.poll.scheduleCancelable(
            { seconds: nowSecs + 60n, nanoseconds: 0 },
        );
    }

    cancel(): void {
        this.cancelled = true;
        if (this.pendingToken) {
            this.pendingToken.cancel();
            this.pendingToken = undefined;
        }
    }
}

Cancellation via State Flag

For simpler cases, just use a boolean flag — the next scheduled poll checks it and exits early:

poll(): void {
    if (this.cancelled) return;
    doWork();
    this.scheduleNext(60n);
}

cancel(): void {
    this.cancelled = true;
}

Cancellation from the CLI

Schedule with an explicit idempotency key and cancel the pending invocation:

# Schedule with a known idempotency key
golem agent invoke --trigger --schedule-at 2026-03-15T10:30:00Z -i 'poll-next' 'PollerAgent("my-poller")' poll

# Cancel the pending invocation
golem agent invocation cancel 'PollerAgent("my-poller")' 'poll-next'

Common Use Cases

Periodic Polling

Check an external API or queue for new work at regular intervals:

poll(): void {
    const items = fetchPendingItems();
    for (const item of items) {
        process(item);
    }
    this.scheduleNext(60n);
}

Periodic Cleanup

Remove expired data or stale resources on a schedule:

cleanup(): void {
    this.entries = this.entries.filter(e => !e.isExpired());
    this.scheduleNext(3600n); // run hourly
}

Heartbeat / Keep-Alive

Periodically notify an external service that the agent is alive:

heartbeat(): void {
    sendHeartbeat(this.serviceUrl);
    this.scheduleNext(30n); // every 30s
}

Helper for Scheduling Self

Extract the scheduling logic into a helper to keep methods clean:

private scheduleNext(delaySecs: bigint): void {
    const self = PollerAgent.get(this.name);
    const nowSecs = BigInt(Math.floor(Date.now() / 1000));
    self.poll.schedule({ seconds: nowSecs + delaySecs, nanoseconds: 0 });
}

Key Points

• The agent is durable — if it crashes, the pending scheduled invocation still fires and the agent recovers
• Invocations are sequential — no concurrent executions of poll on the same agent
• Each .schedule() call is a fire-and-forget enqueue; the current invocation completes immediately
• Use a state flag or generation counter to stop the loop gracefully
• Keep the scheduled method idempotent — it may be retried on recovery

Recovery & Oplog Growth

Each scheduled tick (heartbeat, poll, cleanup) appends entries to the agent's oplog. For long-running or high-frequency recurring tasks, the oplog grows unboundedly, and recovery on crash will replay the full history — which becomes slow over time.

You cannot opt out of oplog writes for a durable agent. The fix is snapshot-based recovery: enable periodic snapshotting so recovery starts from the latest snapshot instead of replaying every prior tick. See golem-custom-snapshot-ts for the snapshotting: { every: N } / snapshotting: { periodic: ... } decorator option and saveSnapshot / loadSnapshot overrides.