> ## Documentation Index
> Fetch the complete documentation index at: https://docs.capriole.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Messages

> 通过 Capriole AI Claude 模型创建 Anthropic Messages 兼容输出。

当应用、SDK 或代理需要 Anthropic Messages 请求与响应格式时，请使用此端点。

发送包含 `model`、`messages` 和 `max_tokens` 的标准 Messages 请求体。Capriole AI 会在转发给上游前，把 latest alias 解析为所选上游 Claude 模型；继续转发 `system`、`tools`、`thinking` 和 `stream` 等兼容字段；并原样返回上游 JSON 或 SSE 流。

`POST /v1/messages` 接受 `claude-latest`、`claude-fable-5`、`claude-opus-5`、`claude-opus-4-8`、`claude-opus-4-7`、`claude-opus-4-6` 和 `claude-sonnet-4-6`。使用 `claude-latest` 可以在不修改配置的情况下选择 Fable 5。

`POST /v1/messages/count_tokens` 接受相同的 Claude 模型 ID，用于执行 Anthropic 兼容的 Token 计数检查。它会返回所选上游的 Token 计数响应或错误。

简单的 Capriole 原生文本生成使用 `POST /v1/chat`。需要 Anthropic Messages 传输格式时，请使用 `POST /v1/messages`。


## OpenAPI

````yaml api-reference/openapi.json POST /v1/messages
openapi: 3.1.0
info:
  title: Capriole AI API
  description: >-
    Public API for model discovery, text chat, and protocol-compatible model
    endpoints.
  version: 1.0.0
servers:
  - url: https://api.caprioletech.com
security: []
paths:
  /v1/messages:
    post:
      summary: Create message
      description: Creates an Anthropic Messages-compatible response for Claude models.
      operationId: createMessage
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/MessagesRequest'
            examples:
              text:
                value:
                  model: claude-latest
                  max_tokens: 1024
                  messages:
                    - role: user
                      content: Hello World!
              streaming:
                value:
                  model: claude-opus-4-7
                  max_tokens: 1024
                  messages:
                    - role: user
                      content: Write a short Python function.
                  stream: true
      responses:
        '200':
          description: Anthropic Messages-compatible JSON response or SSE stream
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MessagesResponse'
            text/event-stream:
              schema:
                type: string
                description: Anthropic Messages-compatible SSE chunks.
        '400':
          $ref: '#/components/responses/ValidationOrDetailErrorResponse'
        '401':
          $ref: '#/components/responses/DetailErrorResponse'
        '403':
          $ref: '#/components/responses/DetailErrorResponse'
        '429':
          $ref: '#/components/responses/RateLimitErrorResponse'
        '500':
          $ref: '#/components/responses/InternalServerErrorResponse'
        '502':
          $ref: '#/components/responses/DetailErrorResponse'
      security:
        - bearerAuth: []
components:
  schemas:
    MessagesRequest:
      type: object
      additionalProperties: true
      required:
        - model
        - messages
        - max_tokens
      properties:
        model:
          type: string
          description: Public Anthropic Messages model identifier or Claude latest alias
          enum:
            - claude-latest
            - claude-fable-5
            - claude-opus-5
            - claude-opus-4-8
            - claude-opus-4-7
            - claude-opus-4-6
            - claude-sonnet-4-6
        messages:
          type: array
          description: Anthropic-compatible conversation messages.
          items:
            $ref: '#/components/schemas/MessagesMessage'
        max_tokens:
          type: integer
          exclusiveMinimum: 0
          description: Maximum number of output tokens.
        system:
          description: Optional Anthropic-compatible system prompt.
          oneOf:
            - type: string
            - type: array
              items:
                $ref: '#/components/schemas/MessagesContentBlock'
        tools:
          type: array
          description: Anthropic-compatible tool definitions.
          items:
            type: object
            additionalProperties: true
        thinking:
          type: object
          description: Anthropic-compatible thinking options.
          additionalProperties: true
        stream:
          type: boolean
          default: false
          description: Stream the response as Anthropic-compatible server-sent events.
    MessagesResponse:
      type: object
      description: Anthropic Messages-compatible response body.
      additionalProperties: true
    MessagesMessage:
      type: object
      additionalProperties: true
      required:
        - role
        - content
      properties:
        role:
          type: string
          description: Message role such as user or assistant.
        content:
          description: Anthropic-compatible message content.
          oneOf:
            - type: string
            - type: array
              items:
                $ref: '#/components/schemas/MessagesContentBlock'
    MessagesContentBlock:
      type: object
      additionalProperties: true
      properties:
        type:
          type: string
          description: Anthropic content block type.
        text:
          type: string
    ValidationError:
      type: object
      required:
        - detail
        - errors
      properties:
        detail:
          type: string
          description: Validation summary
        errors:
          type: array
          items:
            type: string
          description: Per-field validation errors
    DetailError:
      type: object
      required:
        - detail
      properties:
        detail:
          type: string
          description: Error detail from the API
  responses:
    ValidationOrDetailErrorResponse:
      description: Validation error or request-level error response
      content:
        application/json:
          schema:
            oneOf:
              - $ref: '#/components/schemas/ValidationError'
              - $ref: '#/components/schemas/DetailError'
          examples:
            invalidPayload:
              value:
                detail: Invalid input parameters received.
                errors:
                  - >-
                    Field 'body -> input': String should have at least 1
                    character
    DetailErrorResponse:
      description: Error response with a detail message
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DetailError'
          examples:
            missingBearerToken:
              value:
                detail: Missing Bearer token
            invalidApiKey:
              value:
                detail: Invalid API key
            usageMetadataUnavailable:
              value:
                detail: Missing usage metadata
    RateLimitErrorResponse:
      description: Rate limit error response
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DetailError'
          examples:
            rateLimitExceeded:
              value:
                detail: 'Rate limit exceeded: 100 per 1 minute'
    InternalServerErrorResponse:
      description: Internal server error response
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DetailError'
          examples:
            internalServerError:
              value:
                detail: An internal server error occurred. Please try again later.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        Use an API key created in the Capriole AI page. Send it as
        `Authorization: Bearer sk-...`.

````