---
title: "Send a message to a chat session's agent"
method: POST
path: "/api/v1/sessions/{sessionId}/conversation/messages"
tags: ["conversations"]
---

# Send a message to a chat session's agent

`POST /api/v1/sessions/{sessionId}/conversation/messages`

## Path parameters

- `sessionId` string, required — Session identifier, e.g. project-1.

## Request body

- SendConversationMessageRequest
  - `attachments` ConversationImageContentRequest[]
    - `data` string, required
    - `mimeType` string, required
  - `clientMessageId` string
  - `resources` ConversationResourceContentRequest[]
    - `mimeType` string
    - `name` string, required
    - `text` string, nullable
    - `uri` string, required
  - `text` string, required

## Response `202`

Accepted

- SendConversationMessageResponse
  - `duplicate` boolean, required
  - `providerTurnId` string
  - `state` 'queued' | 'running' | 'completed' | 'recovered' | 'interrupted' | 'failed'
  - `turnId` string

## Other responses

- `400` — Bad Request
- `404` — Not Found
- `409` — Conflict
- `500` — Internal Server Error
- `501` — Not Implemented

## Changes

- **2026-09-03** `d31a2d019c47` — 5 info
  - added the optional property `reporting_owner` to the response with the `400` status
  - added the optional property `reporting_owner` to the response with the `404` status
  - added the optional property `reporting_owner` to the response with the `409` status
  - added the optional property `reporting_owner` to the response with the `500` status
  - …1 more
- **2026-08-23** `e7b23ab9a07a` — 1 warning
  - added the new `recovered` enum value to the `state` response property for the response status `202`
- **2026-08-06** `d8396ad2c721` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/composiohq/apis/agent-orchestrator-http-daemon/changes/api/v1/sessions/:sessionId/conversation/messages/post.md)

---

[API](https://skmtc.dev/composiohq/apis/agent-orchestrator-http-daemon.md) · [All operations](https://skmtc.dev/composiohq/apis/agent-orchestrator-http-daemon/llms.txt) · [OpenAPI document](https://skmtc.dev/composiohq/apis/agent-orchestrator-http-daemon/revisions/b94dfb339b8d?raw)