---
title: "Create Conversation"
method: POST
path: "/trips/{trip_id}/conversations"
---

# Create Conversation

`POST /trips/{trip_id}/conversations`

Create a new conversation within an existing trip with a first message.

## Path parameters

- `trip_id` string, required

## Request body

- CreateConversationRequest
  - `message` string, nullable
  - `model_choice` 'fast' | 'deep', nullable
  - `proposal_id` string, uuid, nullable

## Response `200`

Successful Response

- CreateConversationResponse
  - `id` string, required
  - `created_at` string, date-time, required

## Other responses

- `422` — Validation Error

## Changes

- **2026-09-26** `dd78fbd6c358` — 1 info
  - added the new optional request property `proposal_id`

[Change history](https://skmtc.dev/stardrift/apis/fastapi/changes/trips/:trip_id/conversations/post.md)

---

[API](https://skmtc.dev/stardrift/apis/fastapi.md) · [All operations](https://skmtc.dev/stardrift/apis/fastapi/llms.txt) · [OpenAPI document](https://skmtc.dev/stardrift/apis/fastapi/revisions/dd78fbd6c358?raw)