Pgvector is an open-source PostgreSQL extension designed to handle vector similarity searches efficiently. It enables users to store, index, and query embeddings—numeric vector representations of data—within a PostgreSQL database. This makes it particularly useful for machine learning applications, such as those involving natural language processing or image recognition, where comparing embeddings for similarity is required. The extension supports various distance metrics, including Euclidean, cosine, and inner product, to facilitate these searches. Pgvector can be found on GitHub at https://github.com/pgvector/pgvector, where it is actively maintained and includes comprehensive documentation for installation and usage.