spotify/annoy

Health v2 · maintenance only

Adoption not part of the score

14289 stars · 1227 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Annoy is a C++ library with Python (and other language) bindings for approximate nearest neighbor search over high-dimensional vectors. It builds static, memory-mapped index files that can be shared across processes with minimal memory footprint.

Use cases

• find similar items by vector embeddings
• approximate nearest neighbor search in high-dimensional space
• share a vector index across multiple processes via mmap
• build music or content recommendations from factorized vectors
• cosine similarity search over millions of vectors
• load a prebuilt ANN index from a static file in production

When to choose

• you need read-only vector indexes distributed as static files
• memory usage is a prime concern with millions of vectors
• you want simple Python bindings with a fast C++ core
• vectors have relatively low dimensionality (under ~1000)

When to avoid

• you need dynamic inserts or updates to the index after build
• you need exact nearest neighbor results
• you need very high-dimensional vectors or heavy filtering features
• you want a full-featured vector database with metadata and CRUD

Facets

library · maturity stable

search-engine vector-database machine-learning machine-learning databases data-science cpp python cross-platform windows ann nearest-neighbor-search locality-sensitive-hashing mmap embeddings recommendation search linux macos

Member repositories

For agents

markdown · JSON · MCP: product_card(name="spotify/annoy")