---
title: "Start workflow execution"
method: POST
path: "/api/v1/workflows/executions"
tags: ["Workflows"]
---

# Start workflow execution

`POST /api/v1/workflows/executions`

## Request

- Base URL: `https://numonic.ai`
- URL: `https://numonic.ai/api/v1/workflows/executions`
- Auth: API key in header `x-api-key`

Start a new execution of a stored workflow definition. Executions track the per-node state, inputs, and outputs of a single run.

## Request body

- StartExecutionRequest
  - `asset_hash` string, required: Asset hash (40 characters)
  - `workflow_json` object, required: Workflow definition JSON to execute
  - `execution_id` string: Optional client-provided execution ID

## Response `201`

Execution started

- SuccessMessage
  - `message` string, required: Human-readable success message

## Other responses

- `400`: Validation failed

---

[API](https://skmtc.dev/numonic/apis/numonic-api.md) · [All operations](https://skmtc.dev/numonic/apis/numonic-api/llms.txt) · [OpenAPI document](https://skmtc.dev/numonic/apis/numonic-api/revisions/6c559bef1e35?raw)