Anthropic Claude API (primary LLM)

Anthropic's primary API provides programmatic access to the Claude 3.5 and 3.7 model families, specializing in high-reasoning tasks, coding, and vision with a 200,000-token context window.

The Anthropic Claude API serves as the direct gateway to the industry's leading models for complex reasoning and steerability: Claude 3.7 Sonnet and Claude 3.5 Opus. Built on a foundation of Constitutional AI, the API enables developers to integrate advanced capabilities like artifact generation, sophisticated tool use (function calling), and multi-modal vision processing into production environments. With features such as prompt caching to reduce costs by up to 90% and a massive 200k context window, it is engineered for high-scale applications requiring nuanced instruction following and reliable, safe outputs.

https://www.anthropic.com/api