---
title: "Send a message to a UMO"
method: POST
path: "/api/v1/im/messages"
tags: ["IM"]
---

# Send a message to a UMO

`POST /api/v1/im/messages`

**Required scope:** `im`

## Request body

- ImMessageRequest
  - `umo` string, required
  - `message` union, required
    - string
    - MessagePart[]
      - `type` 'text' | 'plain' | 'image' | 'file' | 'audio' | 'record' | 'video' | 'reply', required
      - `text` string
      - `attachment_id` string
      - `url` string
      - `filename` string
      - `stored_filename` string
      - `mime_type` string

## Response `200`

Standard AstrBot success response

- SuccessEnvelope
  - `status` 'ok', required
  - `message` string
  - `data` unknown, required

## Changes

- **2026-07-18** `dcaea15b7823` — 1 info
  - added the new optional request property `message/oneOf[subschema #2]/items/stored_filename`
- **2026-06-14** `6b73b947caab` — 1 info
  - endpoint added
- **2026-03-09** `3d43cee2622a` — 1 breaking
  - api path removed without deprecation

[Change history](https://skmtc.dev/astrbotdevs/apis/astrbot-openapi-v1/changes/api/v1/im/messages/post.md)

---

[API](https://skmtc.dev/astrbotdevs/apis/astrbot-openapi-v1.md) · [All operations](https://skmtc.dev/astrbotdevs/apis/astrbot-openapi-v1/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/astrbotdevs/astrbot-openapi-v1/revisions/9f8da1b16ca0/schema)