Vector Stores & Memory

How AI systems remember. From vector databases for similarity search to higher-level memory layers and the embedding models that feed them, this is the retrieval backbone behind RAG and long-term context.

Pricing
License
Language
Last updated: Show all
Sort: A–Z

Vector Databases

Stores for embeddings and similarity search

Chroma

Chroma

Chroma

Open-source embedding database for RAG — store vectors and query by similarity in a few lines.

v1.5.92026-05-05PythonApache-2.0
28.9k Open source Free tier Paid
LanceDB

LanceDB

LanceDB

Embedded vector database built on the Lance columnar format — serverless and local-first

python-v0.35.0-beta.22026-07-14Rust / PythonApache-2.0
11.0k Open source Free tier Paid
Milvus

Milvus

Zilliz

Open-source vector database built for billion-scale similarity search

v2.6.202026-07-14GoApache-2.0
45.3k Open source Free tier Paid

pgvector

pgvector

Postgres extension for vector similarity search — add agent memory and RAG without a separate database.

v0.8.52026-07-08SQL / CPostgreSQL
22.3k Completely free Open source
Qdrant

Qdrant

Qdrant

High-performance open-source vector database for similarity search and agent memory

v1.18.32026-07-17RustApache-2.0
33.5k Open source Free tier Paid
Weaviate

Weaviate

Weaviate

Open-source vector database with hybrid search, filtering, and built-in vectorizers

v1.38.62026-07-21GoBSD-3-Clause
16.6k Open source Free tier Paid

Agent Memory

Long-term memory layers for agents

Mem0

Mem0

Memory layer for agents — extracts and recalls facts across sessions, not raw chat logs.

v2.0.132026-07-22PythonApache-2.0
61.5k Open source Free tier Paid
Zep

Zep

Zep

Long-term memory layer for agents, building a temporal knowledge graph from conversations

No updates in 6+ monthszep-crewai-v1.1.12025-09-11PythonApache-2.0
4.8k Open source Free tier Paid

Embedding Models

Models that turn text into vectors

Run embedding models locally (e.g. bge-m3) to turn text into vectors for RAG and memory — no API.

v5.6.02026-06-16PythonApache-2.0
18.9k Completely free Open source