Developers initialize Chroma locally via Python (pip install chromadb) or TypeScript (npm install chromadb). Chroma allows creating Collections of documents. When documents or text passages are added, Chroma uses integrated embedding models (such as Sentence Transformers, OpenAI, or Cohere) or accepts pre-computed vector arrays, indexing them alongside structured key-value metadata.
When an application queries the collection, Chroma computes the query embedding and performs Approximate Nearest Neighbor (ANN) search using HNSW indexing algorithms. Chroma combines vector similarity with boolean metadata filters, returning the most semantically relevant document chunks and their associated metadata. In cloud deployments, Chroma Cloud leverages serverless compute workers decoupled from cloud object storage, executing queries efficiently at scale.