Function hook

Spawns a hook execution against an existing workflow job. The hook runs in an isolated dimensional thread within the target job's namespace, allowing it to read/write the same job state without interfering with the main workflow thread.

This is the low-level primitive behind execHook(). Use hook() directly when you need fire-and-forget hook execution or when you manage signal coordination yourself.

Target Resolution

• If taskQueue and workflowName (or entity) are provided, the hook targets that specific workflow type.
• If neither is provided, the hook targets the current workflow. However, targeting the same topic as the current workflow is rejected to prevent infinite loops.

Idempotency

The isSideEffectAllowed guard ensures hooks fire exactly once — on replay, the hook is not re-spawned.

Examples

import { Durable } from '@hotmeshio/hotmesh';

// Fire-and-forget: spawn a hook without waiting for its result
export async function notifyWorkflow(userId: string): Promise<void> {
  await Durable.workflow.hook({
    taskQueue: 'notifications',
    workflowName: 'sendNotification',
    args: [userId, 'Your order has shipped'],
  });
  // Continues immediately, does not wait for the hook
}
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// Manual signal coordination (equivalent to execHook)
export async function manualHookPattern(itemId: string): Promise<string> {
  const signalId = `process-${itemId}`;

  await Durable.workflow.hook({
    taskQueue: 'processors',
    workflowName: 'processItem',
    args: [itemId, signalId],
  });

  // Manually wait for the hook to signal back
  return await Durable.workflow.waitFor<string>(signalId);
}
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// Hook with retry configuration
await Durable.workflow.hook({
  taskQueue: 'enrichment',
  workflowName: 'enrichProfile',
  args: [profileId],
  config: {
    maximumAttempts: 5,
    backoffCoefficient: 2,
    maximumInterval: '1m',
  },
});
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