Directory

Free, moderated open-access preprint server for physics, mathematics, computer science, statistics, quantitative finance, economics and related fields, with an open API and bulk access

Developer API over Brave's independent web index offering web, news, image, video, LLM-context and grounded-answer endpoints on prepaid credits

Web data platform combining residential, datacenter and ISP proxy networks with unblocking, SERP and scraper APIs, remote browsers, ready-made datasets and an MCP server

Membership organization that registers DOIs for scholarly content and exposes the metadata through a free public REST API, content negotiation and the paid Metadata Plus service

Search API for AI agents built on Exa's own web index, offering search, page contents, deep research and asynchronous agent endpoints with Python and JavaScript SDKs

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

Open catalog of the global research system: works, authors, sources, institutions and topics under CC0, served by a REST API, web app and S3 snapshot

Free AI-assisted literature search from Ai2 with an Academic Graph API, recommendations and downloadable datasets of papers, authors and citations

API that returns live search-engine result pages from Google and other engines as structured JSON, with localization, device and search-type parameters

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