---
title: "Send Message"
method: POST
path: "/api/v1/slack/connections/{connection_id}/messages"
tags: ["Slack"]
---

# Send Message

`POST /api/v1/slack/connections/{connection_id}/messages`

## Path parameters

- `connection_id` string, uuid, required

## Headers

- `Idempotency-Key` string, required

## Request body

- SlackMessageSend
  - `conversation_id` string, required
  - `text` string, required
  - `thread_ts` string, nullable

## Response `200`

Successful Response

- SlackActionResponse
  - `id` string, uuid, required
  - `connection_id` string, uuid, required
  - `status` 'sending' | 'sent' | 'failed' | 'unknown', required
  - `conversation_id` string, required
  - `message_ts` string, nullable
  - `thread_ts` string, nullable
  - `error_code` string, nullable
  - `retry_after` integer, nullable — Immediate retry delay in seconds; null on stored outcomes.

## Other responses

- `422` — Validation Error
- `4XX` — Client error with Support Agent information.
- `5XX` — Server error with Support Agent information.

## Changes

- **2026-10-01** `3e0d51f919a7` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/inkbox/apis/inkbox-api/changes/api/v1/slack/connections/:connection_id/messages/post.md)

---

[API](https://skmtc.dev/inkbox/apis/inkbox-api.md) · [All operations](https://skmtc.dev/inkbox/apis/inkbox-api/llms.txt) · [OpenAPI document](https://skmtc.dev/inkbox/apis/inkbox-api/revisions/5cbaa42f14f7?raw)