---
title: "Inject Message"
method: POST
path: "/api/chat/inject"
---

# Inject Message

`POST /api/chat/inject`

Inject a user message into a running agent execution.

The message is queued for the agent to absorb at its next natural
breakpoint (between iterations).  It is also persisted immediately
to the conversation history.

Returns 409 if no active execution exists for the conversation.

## Request body

- InjectMessageRequest — Request body for injecting a message into an active agent execution.
  - `conversation_id` string, required
  - `content` string, required

## Response `200`

Successful Response

- object

## Other responses

- `422` — Validation Error

## Changes

- **2026-03-22** `6dc2d6f33d44` — 2 warning, 7 info
  - removed the optional property `inject_id` from the response with the `200` status
  - removed the optional property `status` from the response with the `200` status
  - api operation id `inject_message_api_chat_inject_post` was added
  - the endpoint scheme security `HTTPBearer` was added to the API
  - …5 more

[Change history](https://skmtc.dev/fim-ai/apis/fim-one-api/changes/api/chat/inject/post.md)

---

[API](https://skmtc.dev/fim-ai/apis/fim-one-api.md) · [All operations](https://skmtc.dev/fim-ai/apis/fim-one-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/fim-ai/fim-one-api/revisions/89738ff55831/schema)