Function execHookBatch

Executes multiple hooks in parallel and awaits all their signal responses, returning a keyed object of results. This is the recommended way to run concurrent hooks — it solves a race condition where calling Promise.all([execHook(), execHook()]) would throw before all waitFor registrations complete.

Three-Phase Execution

1. Fire all hooks via Promise.all (registers streams immediately).
2. Await all signals via Promise.all (all waitFor registrations happen together before any DurableWaitForError is thrown).
3. Combine results into a { [key]: result } map.

Examples

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

// Fan-out to multiple AI agents, gather all perspectives
export async function researchWorkflow(query: string): Promise<Summary> {
  const perspectives = await Durable.workflow.execHookBatch<{
    optimistic: PerspectiveResult;
    skeptical: PerspectiveResult;
    neutral: PerspectiveResult;
  }>([
    {
      key: 'optimistic',
      options: {
        taskQueue: 'agents',
        workflowName: 'analyzeOptimistic',
        args: [query],
      },
    },
    {
      key: 'skeptical',
      options: {
        taskQueue: 'agents',
        workflowName: 'analyzeSkeptical',
        args: [query],
      },
    },
    {
      key: 'neutral',
      options: {
        taskQueue: 'agents',
        workflowName: 'analyzeNeutral',
        args: [query],
      },
    },
  ]);

  // All three results are available as typed properties
  const { synthesize } = Durable.workflow.proxyActivities<typeof activities>();
  return await synthesize(
    perspectives.optimistic,
    perspectives.skeptical,
    perspectives.neutral,
  );
}
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// Parallel validation with different services
const checks = await Durable.workflow.execHookBatch<{
  fraud: { safe: boolean };
  compliance: { approved: boolean };
}>([
  {
    key: 'fraud',
    options: {
      taskQueue: 'fraud-detection',
      workflowName: 'checkFraud',
      args: [transactionId],
    },
  },
  {
    key: 'compliance',
    options: {
      taskQueue: 'compliance',
      workflowName: 'checkCompliance',
      args: [transactionId],
    },
  },
]);

if (checks.fraud.safe && checks.compliance.approved) {
  // proceed with transaction
}
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