{ "$schema": "https://json-schema.org/draft/2020-12/schema", "$id": "#/components/schemas/CreateMessageRequest", "title": "CreateMessageRequest", "type": "object", "required": [ "model", "max_tokens", "messages" ], "properties": { "model": { "type": "string", "description": "The model that will complete your prompt. See the list of available models.", "example": "claude-sonnet-4-6" }, "max_tokens": { "type": "integer", "description": "The maximum number of tokens to generate before stopping. Different models support different maximum values.", "minimum": 1, "example": 1024 }, "messages": { "type": "array", "description": "Input messages. Alternating user and assistant conversational turns. Maximum 100,000 messages per request.", "items": { "$ref": "#/components/schemas/MessageParam" }, "minItems": 1, "example": [] }, "system": { "description": "System prompt providing context and instructions to Claude. Can be a string or array of content blocks.", "oneOf": [ { "type": "string" }, { "type": "array", "items": { "$ref": "#/components/schemas/TextBlockParam" } } ], "example": "example_value" }, "temperature": { "type": "number", "description": "Amount of randomness injected into the response. Ranges from 0.0 to 1.0. Use closer to 0.0 for analytical tasks, closer to 1.0 for creative tasks.", "minimum": 0.0, "maximum": 1.0, "default": 1.0, "example": 42.5 }, "top_p": { "type": "number", "description": "Use nucleus sampling. Recommended to use either temperature or top_p, but not both.", "minimum": 0.0, "maximum": 1.0, "example": 42.5 }, "top_k": { "type": "integer", "description": "Only sample from the top K options for each subsequent token.", "minimum": 1, "example": 10 }, "stop_sequences": { "type": "array", "description": "Custom text sequences that will cause the model to stop generating.", "items": { "type": "string" }, "example": [] }, "stream": { "type": "boolean", "description": "Whether to incrementally stream the response using server-sent events.", "default": false, "example": true }, "metadata": { "$ref": "#/components/schemas/Metadata" }, "tools": { "type": "array", "description": "Definitions of tools that the model may use.", "items": { "$ref": "#/components/schemas/Tool" }, "example": [] }, "tool_choice": { "$ref": "#/components/schemas/ToolChoice" }, "thinking": { "$ref": "#/components/schemas/ThinkingConfig" }, "output_config": { "$ref": "#/components/schemas/OutputConfig" }, "service_tier": { "type": "string", "description": "Service tier to use for this request.", "enum": [ "auto", "standard_only" ], "default": "auto", "example": "auto" }, "cache_control": { "$ref": "#/components/schemas/CacheControl" } } }