How many Memory & Knowledge tools are listed?

9 total. 9 have a free option and 0 are open source.

What's a typical price for Memory & Knowledge tools?

Paid tiers average around $135/month across 2 tools with published pricing. Several tools only list contact-sales pricing and aren't counted here.

Agent Memory & Knowledge Systems

All 9 Memory & Knowledge tools on AgentsIndex. Filter, sort, and compare.

9 listed9 freeavg $135/month

Reviewed by Mathijs Bronsdijk · Updated Apr 13, 2026

The Memory & Knowledge catalog on AgentsIndex lists 9 tools built for this job. Most are built for engineers, developers, mid-market teams. 9 have a free option. It's a maturing category with 9 tracked tools.

pgvector

Store and search vectors in PostgreSQL with pgvector

Memory & Knowledge

pgvector is an open-source PostgreSQL extension for vector search, indexing, and similarity queries inside your Postgres database.

Chroma

Open-source vector database built for fast, scalable AI search

Memory & Knowledge

Chroma is an open-source embedding database for developers building AI apps. Store, query, and retrieve vectors with hybrid search at any scale.

Milvus

Open-source vector database for fast similarity search at scale

Memory & Knowledge

Milvus is a cloud-native vector database for developers building similarity search on massive unstructured data.

Qdrant

Open-source vector database and search engine for AI-scale similarity search

Memory & Knowledge

Qdrant is an open-source vector database written in Rust, built for semantic search, RAG, and recommendation systems at production scale.

Weaviate

Open-source vector database for semantic search, RAG, and agentic AI applications

Memory & Knowledge

Weaviate is an open-source vector database for semantic search and RAG workflows. Store billions of vectors, run hybrid search, and build AI agents. Free to self-host.