---
title: "POST /v1/runs/sync"
method: POST
path: "/v1/runs/sync"
tags: ["Run"]
---

# POST /v1/runs/sync

`POST /v1/runs/sync`

Execute a workflow definition synchronously. Blocks until all nodes
complete and returns the full execution state. Max 60s timeout, 20 nodes.

## Request body

- union
  - object
  - SyncRunParams
    - `definition` WorkflowDefinition, required — Definition is the inline workflow graph to analyze. Same shape as a saved workflow's definition. Unlike the ephemeral-run endpoint there is no trigger restriction — analysis is read-only and method-agnostic.
      - `blockExpansions` object — Set on run snapshots only (not workflow DB)
      - `inputSchema` WorkflowInput[]
        - `description` string
        - `key` string
        - `required` boolean
        - `type` string — "string", "number", "boolean", "object", "array"
      - `nodes` object, required
      - `sensitivePropKeys` string[] — Legacy: kept for old runs; no longer populated for new workflows
      - `triggerNodeIds` string[] — TriggerNodeIDs lists the node IDs that are trigger (root) nodes. Every workflow declares this — single-trigger workflows ship ["root"] (the legacy node id), multi-trigger workflows list every trigger node id. Treating single-trigger as a forest-of-1 removes the two-path branching throughout the BE + FE; older rows without the field are backfilled by migration 000282 and the field-missing path stays as a read-side safety net (see FindTriggerNodeIDs) but is no longer exercised by saves. "root" is also a runtime alias for "the trigger that fired this run" — {{root.X}} variable references resolve to the firing trigger regardless of which trigger fired. Don't repurpose the literal "root" as a trigger id on a multi-trigger workflow.
      - `variableDefs` VariableDef[] — VariableDefs is a snapshot of the workflow's declared variables at run creation time. The canonical source lives on the workflows row (Workflow.VariableDefs column). Snapshotted into the run definition so the worker can resolve {{$vars.x}} lookups and route variable-action writes to the right scope without an extra DB round trip.
        - `default` unknown
        - `description` string
        - `lifetime` 'persist' | 'reset'
        - `name` string
        - `type` 'number' | 'text' | 'boolean' | 'list' | 'object'
    - `payload` object
    - `propValues` object

## Response `200`

OK

- SyncRunResponse
  - `durationMs` integer
  - `executionState` object
  - `runId` string
  - `status` string

## Other responses

- `400` — Bad Request
- `402` — Payment Required

---

[API](https://skmtc.dev/b3os/apis/b3os-workflow-api.md) · [All operations](https://skmtc.dev/b3os/apis/b3os-workflow-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/b3os/b3os-workflow-api/revisions/a8c7af3c66a1/schema)