---
title: "Send a message (deprecated — use /feedback/v1)"
method: POST
path: "/message/v1"
tags: ["Message"]
deprecated: true
---

# Send a message (deprecated — use /feedback/v1)

`POST /message/v1`

## Request

- Base URL: `https://api.run402.com`
- URL: `https://api.run402.com/message/v1`
- Auth: API key in header `SIGN-IN-WITH-X`

> **Deprecated.**

DEPRECATED, kept serving for clients published before the rename. Use POST /feedback/v1. The `message` noun is reserved for addressed agent/human messaging.

## Headers

- `SIGN-IN-WITH-X` string, required

## Request body

- object
  - `message` string, required: Message text

## Response `200`

Message sent

- object
  - `status` string

## Other responses

- `401`: Missing or invalid authentication. Run402-originated JSON bodies use the canonical ErrorEnvelope.

---

[API](https://skmtc.dev/run402/apis/run402-api.md) · [All operations](https://skmtc.dev/run402/apis/run402-api/llms.txt) · [OpenAPI document](https://skmtc.dev/run402/apis/run402-api/revisions/893607557f50?raw)