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

Open-source, offline-first API client that stores collections as plain-text .bru files in a Git repository, with a CLI for running requests in CI

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

Québec's shared open-data portal where provincial ministries and municipalities publish datasets under a Creative Commons Attribution licence

Statistical office of the European Union publishing harmonised EU and member-state data through the Data Browser, bulk downloads and SDMX/JSON APIs

Minimal, unopinionated web framework for Node.js with routing and middleware, the long-standing default for HTTP servers in the Node ecosystem

Identity-based secrets manager providing encrypted key-value storage, dynamic database and cloud credentials, PKI and encryption-as-a-service, under the Business Source License

Small TypeScript web framework built on Web Standard APIs that runs unchanged on Cloudflare Workers, Deno, Bun, Node.js and other JavaScript runtimes

Open-source API client that runs in the browser or as a desktop app, supports REST, GraphQL and realtime protocols, and can be self-hosted for teams

The IMF's statistical portal for World Economic Outlook, fiscal, balance-of-payments, reserves and price datasets with SDMX 2.1 and 3.0 APIs

REST, WebSocket and FIX interfaces to the Kraken cryptocurrency exchange for market data, spot and derivatives trading and account management

Rust search engine for application search-as-you-type with typo tolerance, faceting and hybrid semantic search; MIT core plus BSL enterprise parts

Vendor-neutral, machine-readable standard for describing HTTP APIs in JSON or YAML, maintained by the OpenAPI Initiative under the Linux Foundation

Free API and web tool from Bloomberg for mapping tickers, ISINs, CUSIPs and other identifiers to public-domain FIGI instrument identifiers, with search and filter endpoints

Non-profit registry of persistent researcher identifiers (ORCID iDs) with user-controlled records, Public and Member APIs, OAuth sign-in and an annual CC0 public data file

Free, open-source research management platform from the Center for Open Science for projects, preregistrations, registries, preprint services and linking outputs across storage providers

Read-only query service for OpenStreetMap data using the Overpass QL language, available on public instances or self-hosted

Python data-validation library using type hints to parse, validate and serialize models, with a Rust core; the schema layer behind FastAPI and many LLM SDKs

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

GPL-licensed in-memory search engine in C++ offering typo-tolerant instant search, faceting, vector and hybrid search, with Typesense Cloud hosting

The Internet Archive's public web archive for browsing historical snapshots of web pages, with Save Page Now, Availability, CDX and Memento APIs

Free access to World Bank development indicators by country and year through a web portal, bulk downloads and a public REST API