What is Weaviate and what are its main features?

Weaviate is an open-source vector database written in Go that supports vector search, hybrid search, and a module system for built-in vectorization, reranking, and generative AI integration. It exposes both REST and GraphQL APIs and supports multi-tenancy, replication, and horizontal scaling. Weaviate can automatically vectorize data at ingest using configured embedding modules from OpenAI, Cohere, Hugging Face, or local models, removing the need for a separate embedding pipeline. It runs self-hosted or on Weaviate Cloud.