Unsupervised Passage Reranking alternatives for AI agents.

Privacy-respecting metasearch engine

Retrieval and Retrieval-augmented LLMs

💡 All-in-one AI framework for semantic search, LLM orchestration and language model workflows

🔎 Open source distributed and RESTful search engine.

📑 PageIndex: Document Index for Vectorless, Reasoning-based RAG

Free and Open Source, Distributed, RESTful Search Engine

🦔 Fast, lightweight & schema-less search backend. An alternative to Elasticsearch that runs on a few MBs of RAM.

high-performance graph database for real-time use cases

Tantivy is a full-text search engine library inspired by Apache Lucene and written in Rust

Weaviate is an open-source vector database that stores both objects and vectors, allowing for the combination of vector search with structured filtering with the fault tolerance and scalability of a cloud-native database​.

SearXNG is a free internet metasearch engine which aggregates results from various search services and databases. Users are neither tracked nor profiled.

Scira (Formerly MiniPerplx) is a minimalistic AI-powered search engine that helps you find information on the internet and cites it too. Powered by Vercel AI SDK!

A Simple and Universal Swarm Intelligence Engine, Predicting Anything. 简洁通用的群体智能引擎，预测万物

[EMNLP2025] "LightRAG: Simple and Fast Retrieval-Augmented Generation"

Cognee is the open-source AI memory platform for agents. Give your AI agents persistent long-term memory across sessions with a self-hosted knowledge graph engine.

AI coding assistant skill (Claude Code, Codex, OpenCode, Cursor, Gemini CLI, and more). Turn any folder of code, SQL schemas, R scripts, shell scripts, docs, papers, images, or videos into a queryable knowledge graph. App code + database schema + infrastructure in one graph.