> ## Documentation Index > Fetch the complete documentation index at: https://docs.anyfast.ai/llms.txt > Use this file to discover all available pages before exploring further. # claude-opus-5 > Send text, images, prior assistant turns, and tool results. Claude Opus 5 generates the next message and can return text, thinking, or tool-use content blocks. ## OpenAPI ````yaml api-reference/model-api/anthropic/openapi/claude-opus-5/openapi.yaml POST /v1/messages openapi: 3.1.0 info: title: Claude Opus 5 description: >- Anthropic Claude Opus 5 via AnyFast. The model has a 1M-token context window, supports up to 128K output tokens, and uses adaptive thinking by default. version: 1.0.0 servers: - url: https://www.anyfast.ai security: - bearerAuth: [] paths: /v1/messages: post: summary: Create a Message description: >- Send text, images, prior assistant turns, and tool results. Claude Opus 5 generates the next message and can return text, thinking, or tool-use content blocks. operationId: createMessageClaudeOpus5 requestBody: required: true content: application/json: schema: type: object required: - model - max_tokens - messages properties: model: type: string enum: - claude-opus-5 description: Model ID. example: claude-opus-5 messages: type: array minItems: 1 description: Input messages. Each message has a role and content. items: type: object required: - role - content properties: role: type: string enum: - user - assistant description: The role of the message author. content: oneOf: - type: string - type: array items: type: object properties: type: type: string enum: - text - image - tool_result text: type: string source: type: object properties: type: type: string enum: - base64 - url media_type: type: string data: type: string url: type: string format: uri tool_use_id: type: string content: oneOf: - type: string - type: array items: type: object is_error: type: boolean description: >- The content of the message. Either a string or an array of content blocks. example: - role: user content: Hello, Claude! max_tokens: type: integer minimum: 1 maximum: 128000 description: >- The maximum number of tokens to generate before stopping. Claude Opus 5 supports up to 128K output tokens. example: 4096 system: oneOf: - type: string - type: array items: type: object properties: type: type: string text: type: string description: System prompt. Provides context and instructions to Claude. metadata: type: object properties: user_id: type: string description: >- An external identifier for the user who is associated with the request. description: An object describing metadata about the request. stop_sequences: type: array items: type: string description: >- Custom text sequences that will cause the model to stop generating. stream: type: boolean default: false description: >- Whether to incrementally stream the response using server-sent events. tools: type: array items: type: object required: - name - input_schema properties: name: type: string description: Name of the tool. description: type: string description: Description of what the tool does. input_schema: type: object description: JSON Schema for the tool input. description: Definitions of tools that the model may use. tool_choice: type: object required: - type properties: type: type: string enum: - auto - any - tool default: auto description: How the model should use the provided tools. name: type: string description: The name of the tool to use (when type is "tool"). description: How the model should use the provided tools. output_config: type: object properties: effort: type: string enum: - low - medium - high - xhigh - max default: high description: >- Controls adaptive thinking depth and token usage. Claude Opus 5 defaults to high. description: >- Output controls for models that support adaptive thinking effort. thinking: type: object required: - type properties: type: type: string enum: - adaptive - disabled default: adaptive description: >- Whether to explicitly use adaptive thinking or disable thinking. description: >- Adaptive thinking is the default. Manual extended thinking is not supported. Disabling thinking is valid only with low, medium, or high effort; xhigh or max returns a 400 error. responses: '200': description: Message created successfully content: application/json: schema: $ref: '#/components/schemas/Message' '400': description: Invalid request content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/Error' components: schemas: Message: type: object required: - id - type - role - content - model - stop_reason - usage properties: id: type: string example: msg_01XFDUDYJgAACzvnptvVoYEL type: type: string example: message role: type: string example: assistant content: type: array items: type: object properties: type: type: string enum: - text - thinking - tool_use text: type: string thinking: type: string signature: type: string id: type: string name: type: string input: type: object example: - type: text text: Hello! How can I help you today? model: type: string example: claude-opus-5 stop_reason: type: string enum: - end_turn - max_tokens - stop_sequence - tool_use - refusal - null description: Includes `refusal` for requests that the model declines. stop_sequence: type: string nullable: true stop_details: type: object nullable: true additionalProperties: true description: Additional stop information when the serving platform provides it. usage: type: object properties: input_tokens: type: integer output_tokens: type: integer cache_creation_input_tokens: type: integer cache_read_input_tokens: type: integer cache_creation: type: object properties: ephemeral_1h_input_tokens: type: integer ephemeral_5m_input_tokens: type: integer output_tokens_details: type: object properties: thinking_tokens: type: integer Error: type: object properties: type: type: string example: error error: type: object properties: type: type: string example: invalid_request_error message: type: string example: Invalid request parameters securitySchemes: bearerAuth: type: http scheme: bearer ````