Models API Enhancement

The Claude Models API has been expanded to include comprehensive capability metadata, allowing developers to programmatically discover model specifications without hardcoding values.

What's Changed

The GET /v1/models and GET /v1/models/{model_id} endpoints now return three new fields:

• max_input_tokens: Maximum input tokens the model supports
• max_tokens: Maximum output tokens the model supports
• capabilities object: A structured field describing model features and capabilities

Developer Impact

This update eliminates the need for developers to maintain hardcoded knowledge of model specifications. Instead, applications can query the API at runtime to:

• Dynamically select models based on required capabilities
• Validate request parameters against model constraints
• Build adaptive systems that adjust to model capability changes
• Simplify multi-model applications with centralized capability discovery

Getting Started

Simply query the Models API as you normally would—the new fields are automatically included in responses. Reference the Models API documentation for complete details on the new capability object structure and available fields.