conductor-skills

Example: Parallel Branches with FORK_JOIN

Run independent tasks in parallel, then converge before continuing. Always pair FORK_JOIN with a JOIN that lists every parallel branch’s terminal taskReferenceName.

Pattern

       ┌─→ branch_a_task ─┐
fork ──┤                  ├─→ join ─→ next
       └─→ branch_b_task ─┘

Workflow

See workflows/fork-join.json. Key tasks:

{
  "name": "fork", "taskReferenceName": "fork", "type": "FORK_JOIN",
  "forkTasks": [
    [{"name": "fetch_inventory", "taskReferenceName": "inventory", "type": "HTTP", "inputParameters": {"http_request": {"uri": "${workflow.input.inventoryUrl}", "method": "GET"}}}],
    [{"name": "fetch_pricing",   "taskReferenceName": "pricing",   "type": "HTTP", "inputParameters": {"http_request": {"uri": "${workflow.input.pricingUrl}",   "method": "GET"}}}]
  ]
},
{
  "name": "join", "taskReferenceName": "join", "type": "JOIN",
  "joinOn": ["inventory", "pricing"]
}

Run

conductor workflow create examples/workflows/fork-join.json
conductor workflow start -w parallel_fetch -i '{"inventoryUrl": "https://...", "pricingUrl": "https://..."}'

Reading the output

Each branch’s output is available as ${branchRef.output...} in tasks after the JOIN. The JOIN task’s own output aggregates branch outputs by reference name:

${join.output.inventory.response.body}
${join.output.pricing.response.body}

Notes

• Branches in forkTasks are arrays of arrays — one inner array per parallel branch. Each inner array can itself be a sequence of tasks.
• joinOn must list the last task’s taskReferenceName from each branch.
• Failure in any branch fails the JOIN unless every task in that branch is optional: true.
• For dynamic branch counts, use FORK_JOIN_DYNAMIC (see workflow-definition.md).

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