---
title: "Send a signal by correlation key"
method: POST
path: "/workflows/signals/{name}"
tags: ["Workflow signals"]
---

# Send a signal by correlation key

`POST /workflows/signals/{name}`

## Request

- Base URL: `https://api.nullplatform.com`
- URL: `https://api.nullplatform.com/workflows/signals/{name}`
- Auth: HTTP bearer

Delivers a signal to the non-terminal execution of `workflowId` matching `correlationKey`. With `startIfMissing: true`, starts a new execution (using `startInputs`) when none is waiting.

## Path parameters

- `name` string, required

## Request body

- object
  - `correlationKey` string, required
  - `workflowId` string, required
  - `payload` unknown
  - `aliasName` string
  - `revision` integer
  - `startIfMissing` boolean
  - `startInputs` object: Run inputs used only when a new execution is started.

## Response `200`

The signal was delivered (or a new execution started).

- object
  - `delivered` true
  - `executionId` string
  - `started` boolean

## Other responses

- `4XX`: Client error. The body says what went wrong: an error `type`, a human-readable `detail`, and, on validation failures, one entry per offending field.
- `5XX`: Unexpected server error.

## Changes

- **2026-09-17** `43b3c1ecdfd8`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/nullplatform/apis/nullplatform-api/changes/workflows/signals/:name/post.md)

---

[API](https://skmtc.dev/nullplatform/apis/nullplatform-api.md) - [All operations](https://skmtc.dev/nullplatform/apis/nullplatform-api/llms.txt) - [OpenAPI document](https://skmtc.dev/nullplatform/apis/nullplatform-api/revisions/d3f66bc633d4?raw)