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v0 Platform API/API Reference/Chats

Send Message

Creates a new message in an existing chat. Triggers a model response using the provided prompt, with optional attachments and configuration settings.

POST/v1/chats/{chatId}/messages

Usage

TypeScript Example
import { v0 } from 'v0-sdk'

const result = await v0.chats.sendMessage({
  chatId: '123',
  message: 'Add dark mode',
})

console.log(result)

API Signature

Request

Path Parameters

chatId: string

The unique identifier of the chat to send the message to. Provided as a path parameter.

Body

message: string

The prompt or instruction to send to the model as part of the chat.

attachments?: object[]

A list of files or assets to include with the message.

url: string
modelConfiguration?: object

Overrides for the model behavior.

modelId?: 'v0-1.5-sm' | 'v0-1.5-md' | 'v0-1.5-lg' | 'v0-gpt-5'
deprecated

Deprecated Model ID field preserved for backward compatibility.

imageGenerations?: boolean

Enables image generations to generate up to 5 images per version.

thinking?: boolean

Enables thinking to generate a response in multiple steps.

responseMode?: 'sync' | 'async' | 'experimental_stream'

Controls how the response is delivered.

  • "sync": The response is returned immediately with the HTTP request.
  • "async": Returns a message placeholder immediately; use getById to poll for completion status and final output.
  • "experimental_stream": Returns content parts as Server-Sent Events for real-time streaming.

Response

id: string

A unique identifier for the chat.

object: 'chat'

Fixed value identifying this object as a chat.

shareable: boolean

Indicates whether the chat can be shared via public link.

privacy: 'public' | 'private' | 'team' | 'team-edit' | 'unlisted'

Defines the visibility of the chat—private, team-only, or public.

name?: string

An optional name assigned to the chat by the user.

title?: string
deprecated

Deprecated title field preserved for backward compatibility.

createdAt: string

The ISO timestamp representing when the chat was created.

updatedAt?: string

The ISO timestamp of the last update to the chat.

favorite: boolean

Indicates whether the chat is marked as a favorite.

authorId: string

The ID of the user who created the chat.

projectId?: string

Optional ID of the v0 project associated with this chat.

webUrl: string

Web URL to view this chat in the browser.

apiUrl: string

API URL to access this chat via the API.

latestVersion?: object

Full details of the most recent generated version, if available.

id: string

A unique identifier for the version.

object: 'version'

Fixed value identifying this object as a version.

status: 'pending' | 'completed' | 'failed'

The current status of the version generation process.

demoUrl?: string

Optional URL for previewing the generated output.

createdAt: string

The date and time when the version was created, in ISO 8601 format.

updatedAt?: string

The date and time when the version was last updated, in ISO 8601 format.

files: object[]

A list of files that were generated or included in this version.

url: string
deprecated

The canonical URL to access this chat.

messages: object[]

All messages exchanged in the chat, including user and assistant entries.

id: string

A unique identifier for the message.

object: 'message'

Fixed value identifying this object as a message.

content: string

The main text content of the message.

experimental_content?: string[]

The parsed content of the message as an array structure containing AST nodes. This is an experimental field that may change.

createdAt: string

The ISO timestamp representing when the message was created.

updatedAt?: string

The ISO timestamp representing when the message was last updated.

type: 'message' | 'forked-block' | 'forked-chat' | 'open-in-v0' | 'refinement' | 'added-environment-variables' | 'added-integration' | 'deleted-file' | 'moved-file' | 'renamed-file' | 'edited-file' | 'replace-src' | 'reverted-block' | 'fix-with-v0' | 'auto-fix-with-v0' | 'sync-git'

Indicates the format or category of the message, such as plain text or code.

role: 'user' | 'assistant'

Specifies whether the message was sent by the user or the assistant.

finishReason?: 'stop' | 'length' | 'content-filter' | 'tool-calls' | 'error' | 'other' | 'unknown'

The reason why the message generation finished.

apiUrl: string

API URL to access this message via the API.

parentId?: stringnull

The ID of the parent message.

files?: object[]

Optional array of files associated with the chat context.

lang: string

Programming language used in the file (e.g., JavaScript, Python).

meta: object

A key-value map of metadata associated with the file (e.g., path, type).

source: string

The origin or identifier of the file source (e.g., path or upload label).

demo?: string
deprecated

Deprecated demo URL used for previewing the chat result.

text: string

The main user prompt or instruction that started the chat.

modelConfiguration?: object

The configuration used to generate responses in this chat.

modelId?: 'v0-1.5-sm' | 'v0-1.5-md' | 'v0-1.5-lg' | 'v0-gpt-5'
deprecated

Deprecated Model ID field preserved for backward compatibility.

imageGenerations?: boolean

Enables image generations to generate up to 5 images per version.

thinking?: boolean

Enables thinking to generate a response in multiple steps.

permissions: object
write: boolean

If true, the user has write access to the chat.

Fork Chat

Creates a new chat fork from a specific version within an existing chat. Useful for branching off alternate directions without modifying the original conversation.

Find Chat Messages

Retrieves a list of all messages for a specific chat, ordered by creation date (newest first). Supports cursor-based pagination and includes message content, role, and type information.