Anthropic is launching Citations, a new API feature that enables Claude to provide detailed references to the exact sentences and passages it uses to generate responses. This feature is generally available on the Anthropic API and Google Cloud’s Vertex AI, addressing a specific need in AI applications: verifying the sources behind AI-generated responses. With Citations, developers can create AI solutions that offer enhanced accountability across use cases like document summarization, complex Q&A, and customer support. The feature uses token-based pricing and offers superior flexibility and ease of use, seamlessly integrating with the Messages API. Internal evaluations show that Claude's built-in citation capabilities outperform most custom implementations, increasing recall accuracy by up to 15%. Thomson Reuters and Endex are already using Citations in their AI platforms, citing improved accuracy and trustworthiness in AI-generated content.