> ## Documentation Index > Fetch the complete documentation index at: https://docs.connie.ai/llms.txt > Use this file to discover all available pages before exploring further. # Send a message > Sends your message to Connie in a chat and starts the reply. The call returns 202 as soon as the turn starts; the reply is not in this response. It is saved to the chat when the turn finishes, so read it with List chat messages. Turns cost credits like any chat turn, and only one turn runs in a chat at a time. ## OpenAPI ````yaml /openapi/chat.yaml post /brain/start openapi: 3.1.0 info: title: Connie Chat API version: 1.0.0 description: > Endpoints the Connie web app uses for chat. They authenticate with your signed-in browser session — see https://docs.connie.ai/api-reference/authentication. These are the app's own endpoints and can change when the app changes. servers: - url: https://connie.ai/api security: - sessionCookie: [] tags: - name: Chats description: List, create, rename, pin and delete chats. - name: Turns description: Send a message to Connie and stop a running reply. - name: Chat messages description: Read the saved messages of a chat. - name: Artifacts description: Workflows, tables, canvases, analytics views and apps attached to a chat. - name: Sharing description: >- Share a chat or a single file or canvas, and read a chat through its public link. paths: /brain/start: post: tags: - Turns summary: Send a message description: > Sends your message to Connie in a chat and starts the reply. The call returns 202 as soon as the turn starts; the reply is not in this response. It is saved to the chat when the turn finishes, so read it with List chat messages. Turns cost credits like any chat turn, and only one turn runs in a chat at a time. operationId: sendMessage requestBody: required: true content: application/json: schema: type: object required: - message - workspaceId properties: message: type: string maxLength: 50000 description: >- Your message, up to 50,000 characters. Start it with `/skill-command` to run an enabled skill. workspaceId: type: string format: uuid description: >- Workspace the turn runs in. Required; it must be the chat's workspace. conversationId: type: string format: uuid description: > The chat to post in. Connie reads the chat's earlier messages itself. Without it the turn runs but nothing is saved to a chat. requestId: type: string format: uuid description: > Your own id for this turn. Sending the same id again returns the turn already started instead of starting a second one, so retries are safe. mentions: type: array description: Things you @mentioned, such as a workflow or a call. items: type: object required: - type properties: type: type: string description: What was mentioned, for example `workflow` or `call`. id: type: string displayName: type: string fileAttachmentIds: type: array description: >- Files you uploaded to this chat in the app and want Connie to read with this message. items: type: string format: uuid responses: '202': description: >- The turn started (or, for a repeated `requestId`, had already started). content: application/json: schema: type: object properties: requestId: type: string format: uuid description: Id of this turn. Use it to stop the turn. status: type: string example: running message: type: string '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '402': description: > The workspace is out of credits (`INSUFFICIENT_CREDITS`), or a guest has used their free message (`GUEST_SIGNUP_REQUIRED`). content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: >- You can't post in this chat (`CHAT_FORBIDDEN`), or your workspace role can't run Connie. content: application/json: schema: $ref: '#/components/schemas/Error' '409': description: > Another turn is still running in this chat (`CHAT_BUSY`), the chat changed under you (`CHAT_HISTORY_CONFLICT`), or the chat belongs to an Agent (`AGENT_THREAD`). content: application/json: schema: $ref: '#/components/schemas/Error' '413': description: The chat has grown too large to continue. Start a new chat. content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: > Rate or token budget limit reached (`RATE_LIMIT_EXCEEDED`, `BUDGET_EXCEEDED`), too many turns running in the workspace (`WORKSPACE_QUEUE_FULL`), or the chat reached its tool-call limit (`CONVERSATION_TOOL_CAP`). content: application/json: schema: $ref: '#/components/schemas/Error' components: responses: BadRequest: description: A required field is missing or invalid. content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: >- No valid session (`UNAUTHORIZED`), or the session has expired (`SESSION_EXPIRED`). content: application/json: schema: $ref: '#/components/schemas/Error' schemas: Error: type: object properties: error: type: string description: Human-readable message. code: type: string description: Machine-readable code, when there is one. required: - error securitySchemes: sessionCookie: type: apiKey in: header name: Cookie description: >- The full Cookie header copied from a signed-in connie.ai browser request. See the Authentication page. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.