Bundle Dispatch

bundle/ad-hoc is a dispatch sentinel, not a regular workflow. Submitting a run with name="bundle/ad-hoc" and an input.bundle array of {workflow, input} entries causes the engine to fan out one parallel slot per entry, each running its own per-entry workflow with its own input. The aggregated outputs come back on outputs[] with each entry’s workflow_name and kind populated.

Use bundle when you want a mixed deck of formats from a single brief — e.g. one carousel, one short video, and one text post for the same topic — without paying the round-trip cost of three separate API submissions.

When to pick which

Knob	Shape	Use case
single workflow	`name="<workflow>"`, `input={...}`	One workflow, one output.
`input.variants: 3`	`name="<workflow>"`, `input={..., variants: 3}`	Same workflow, three variant outputs (e.g. three image variants for selection).
`input.bundle: [...]`	`name="bundle/ad-hoc"`, `input={bundle: [...]}`	Different workflows, heterogeneous outputs (mixed-format deck).

input.variants and input.bundle are mutually exclusive — the API rejects submissions that try to combine them.

curl -X POST "$FABRIC_URL/v1/workflows/run?name=bundle/ad-hoc" \
  -H "Authorization: Bearer $FABRIC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": {
      "bundle": [
        {
          "workflow": "carousel/generate",
          "input": { "topic": "AI productivity tips", "slide_count": 5 }
        },
        {
          "workflow": "video/ai-shorts",
          "input": { "topic": "AI productivity tips" }
        },
        {
          "workflow": "global/content-generate",
          "input": { "topic": "AI productivity tips", "content_types": ["text"] }
        }
      ]
    }
  }'

import { FabricClient } from "@fabric-platform/sdk";

const fabric = new FabricClient({ apiKey: process.env.FABRIC_API_KEY });

const run = await fabric.workflows.runs.submit("bundle/ad-hoc", {
  input: {
    bundle: [
      { workflow: "carousel/generate", input: { topic, slide_count: 5 } },
      { workflow: "video/ai-shorts", input: { topic } },
      { workflow: "global/content-generate", input: { topic, content_types: ["text"] } },
    ],
  },
});

Input Shape

Field	Type	Required	Description
`bundle`	`array`	yes	1–10 entries; each runs one parallel slot.
`bundle[].workflow`	`string`	yes	Canonical workflow name (must resolve in the registry for the caller’s org/team).
`bundle[].input`	`object`	no	Input dict passed verbatim to the per-entry workflow. Defaults to `{}`.

Validation runs before any subprocess spawns:

Shape errors (missing workflow, non-object input) collect across every entry — you get a single 400 with a per-index error list.
Each bundle[].workflow is resolved through the hierarchical registry (team → org → global).
When validate=true, each per-entry input is JSON-Schema-validated against its sub-workflow’s input_schema.

Output Shape

The run’s outputs[] contains one entry per bundle slot, in submission order:

{
  "id": "...",
  "workflow_name": "bundle/ad-hoc",
  "outputs": [
    {
      "variant_index": 0,
      "workflow_name": "carousel/generate",
      "kind": "carousel",
      "output": { "kind": "carousel", "topic": "...", "slides": [ ... ] }
    },
    {
      "variant_index": 1,
      "workflow_name": "video/ai-shorts",
      "kind": "video",
      "output": { "platform_exports": [ ... ], "script": { ... } }
    },
    {
      "variant_index": 2,
      "workflow_name": "global/content-generate",
      "kind": "text",
      "output": { "title": "...", "content": "...", "tags": [ ... ] }
    }
  ]
}

The run row is recorded under workflow_name = "bundle/ad-hoc" so the audit trail and quota accounting see one logical run; the per-slot workflow names live on each output entry.

Limits

Limit	Value	Reason
`bundle` length	1–10	Matches the `variants` cap; single subprocess fan-out budget.
Mutually exclusive with	`input.variants`	The two knobs share the same fan-out budget.

Errors

Code	When
400 `bundle_shape_invalid`	One or more entries are malformed (missing `workflow`, non-object `input`, etc.). The `details.errors` array carries one entry per malformed bundle index.
400 `bundle_unknown_workflow`	One or more `bundle[].workflow` names don’t resolve in the registry.
400 plain	`name=bundle/ad-hoc` submitted without an `input.bundle` array — see the input shape above.