Exa, formerly known as Metaphor, is an AI API designed to connect your AI applications to the internet. Exa is focused on intelligent web search and retrieval.

It uses an embeddings-based search to retrieve relevant web content, giving AI programs access to wide spans of knowledge. The Exa API is primarily known for its flexible search capabilities and its ability to handle a variety of query types, including those requiring semantic understanding.

It uses a state-of-the-art web embeddings model over a custom index for these kinds of queries, as well as traditional keyword-based search for all other types.

Exa allows the user to instantly retrieve full text content from any page in its index. It also offers customization features, such as the ability to apply filters or specify date ranges, which allow search over a subset of the web tailored to the user's needs.

Notably, Exa's search approach is unique as it uses a novel link prediction transformer that suggests links matching the meaning of a prompt. Not only does it improve the search results, but Exa also offers research tools for creating applications like news summarizers, competitor analysis tools, and research information synthesizers.

Overall, Exa is seen as a major advancement in leveraging AI for web search and analysis.