Directory

Open-source embedding database with a minimal Python and JavaScript API, usable in-process, as a server or through Chroma Cloud

AI search engine over peer-reviewed literature that synthesizes answers, shows a Consensus Meter for yes/no questions and summarizes studies

Python framework for programming language-model pipelines with typed signatures and modules, then optimizing prompts and weights automatically against a metric

AI research assistant that finds papers, extracts structured data from them into tables and runs systematic-review style workflows and reports

Web data API that scrapes, crawls, maps and searches websites and returns clean Markdown or structured JSON for LLM pipelines, with an AGPL-licensed self-hostable core

Prefix-style API from Jina AI that converts any public URL into LLM-ready Markdown (r.jina.ai) or returns web search results with content (s.jina.ai), with open-source server code

Embedded property-graph database with Cypher, vector and full-text search; MIT-licensed but archived in October 2025 after the company was acquired

Open-source Python and JavaScript framework whose create_agent harness builds tool-using agents on the LangGraph runtime with swappable model providers and middleware

Open-source Python framework for retrieval-augmented agents over your data, with connectors, indexes, query engines and event-driven workflows, alongside the commercial LlamaParse document platform

Open-source vector database from Zilliz with Lite, Standalone and Distributed deployments, many index types and GPU acceleration

Native property-graph database queried with Cypher, offered as a GPL community edition, a commercial enterprise edition and the AuraDB cloud service

PostgreSQL extension adding vector types, distance operators and HNSW/IVFFlat indexes for similarity search inside the database

Fully managed, proprietary vector database service with serverless indexes, namespaces, metadata filtering and integrated embedding and reranking

Open-source vector search engine written in Rust with filterable HNSW indexes, sparse and multi-vector support, REST/gRPC APIs and a managed cloud

Open-source Python library for evaluating LLM and RAG applications with LLM-driven and custom metrics, experiments, dataset management and result tracking

Python library for computing and training embedding, cross-encoder reranker, sparse and multi-vector retrieval models, maintained by Hugging Face with thousands of pretrained models on the Hub

Web search, extraction, crawling and research API designed for LLM agents, returning concise source content with SDKs, framework integrations and a hosted MCP server

Hosted embedding and reranking models for retrieval, including code, finance, law and multimodal variants, offered by MongoDB with a free token allowance and pay-as-you-go API

Open-source vector database in Go with pluggable vectorizer modules, hybrid BM25 and vector search, multi-tenancy and a managed cloud