> ## Documentation Index > Fetch the complete documentation index at: https://omer-914cc1c6.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Assistant message > Generates a response message from the assistant for the specified domain. ## Rate limits The assistant API has the following limits: * 10,000 uses per key per month * 10,000 requests per Mintlify organization per hour * 10,000 requests per IP per day ## Suggested usage For best results, use the [useChat hook from ai-sdk](https://ai-sdk.dev/docs/reference/ai-sdk-ui/use-chat#usechat) to send requests and handle responses. You can set `fp`, `threadId`, and `filter` in the `body` field of the options parameter passed to the hook. ## OpenAPI ````yaml POST /assistant/{domain}/message openapi: 3.0.1 info: title: Mintlify Assistant API description: An API to integrate Mintlify discovery features into your product. version: 1.0.0 servers: - url: https://api-dsc.mintlify.com/v1 security: - bearerAuth: [] paths: /assistant/{domain}/message: post: summary: Assistant message description: >- Generates a response message from the assistant for the specified domain. parameters: - name: domain in: path required: true schema: type: string description: >- The domain identifier from your `domain.mintlify.app` URL. Can be found in the top left of your dashboard. requestBody: required: true content: application/json: schema: type: object required: - fp - messages properties: fp: type: string description: >- Browser fingerprint or arbitrary string identifier. There may be future functionality which allows you to get the messages for a given fingerprint threadId: default: null type: string description: >- An optional identifier used to maintain conversation continuity across multiple messages. When provided, it allows the system to associate follow-up messages with the same conversation thread. The threadId is returned in the response as event.threadId when event.type === 'finish'. messages: type: array default: - id: foobar role: user content: how do i get started parts: - type: text text: How do I get started items: type: object properties: id: type: string description: Unique identifier for the message role: type: string enum: - system - assistant - data - user description: The role of the message sender createdAt: type: string format: date-time description: Timestamp when the message was created content: type: string description: The content of the message annotations: type: array items: {} description: Optional array of annotations for the message parts: type: array items: oneOf: - type: object properties: type: type: string enum: - text text: type: string required: - type - text - type: object properties: type: type: string enum: - reasoning reasoning: type: string details: type: array items: oneOf: - type: object properties: type: type: string enum: - text text: type: string signature: type: string required: - type - text - type: object properties: type: type: string enum: - redacted data: type: string required: - type - data required: - type - reasoning - details - type: object properties: type: type: string enum: - step-start required: - type - type: object properties: type: type: string enum: - source source: type: object properties: sourceType: type: string enum: - url id: type: string url: type: string title: type: string required: - sourceType - id - url required: - type - source - type: object properties: type: type: string enum: - tool-invocation toolInvocation: oneOf: - type: object properties: state: type: string enum: - partial-call step: type: number toolCallId: type: string toolName: type: string args: {} required: - state - toolCallId - toolName - args - type: object properties: state: type: string enum: - call step: type: number toolCallId: type: string toolName: type: string args: {} required: - state - toolCallId - toolName - args - type: object properties: state: type: string enum: - result step: type: number toolCallId: type: string toolName: type: string args: {} result: {} required: - state - toolCallId - toolName - args - result required: - type - toolInvocation description: >- Array of message parts with different types including text, reasoning, sources, and tool invocations experimental_attachments: type: array items: type: object properties: name: type: string contentType: type: string url: type: string required: - url description: >- Optional array of experimental attachments for the message required: - id - role - content - parts description: >- Array of messages in the conversation. On the frontend, you will likely want to use the handleSubmit function from the @ai-sdk package's useChat hook to append user messages and handle streaming responses, rather than manually defining the objects in this array as they have so many parameters. retrievalPageSize: type: number default: 5 description: Number of retrieval results to return filter: type: object default: null properties: version: type: string description: Optional version filter language: type: string description: Optional language filter description: Optional filter criteria for the search responses: '200': description: Message generated successfully content: application/json: schema: type: object description: >- Response object that streams formatted data stream parts with the specified status, headers, and content. This matches what is expected from the AI SDK as documented at [ai-sdk.dev/docs/ai-sdk-ui/streaming-data](https://ai-sdk.dev/docs/ai-sdk-ui/streaming-data). Instead of writing your own parser, it is recommended to use the [useChat hook from ai-sdk as documented here](https://ai-sdk.dev/docs/reference/ai-sdk-ui/use-chat#usechat). components: securitySchemes: bearerAuth: type: http scheme: bearer description: >- The Authorization header expects a Bearer token. See the [Assistant API Key documentation](/docs/api-reference/introduction#assistant-api-key) for details on how to get your API key. ````