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

Python web framework for building HTTP APIs from type-annotated functions, with automatic validation through Pydantic and generated OpenAPI documentation

Free economic database from the St. Louis Fed aggregating hundreds of thousands of US and international time series, with graphs, vintages (ALFRED), an Excel add-in and a keyed JSON/XML API

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

Open-source Python SDK and self-hosted AI gateway that calls 100+ LLM providers in the OpenAI format, with routing, fallbacks, virtual keys, budgets, spend tracking and logging callbacks

C/C++ inference engine for LLMs and vision-language models with GGUF quantized weights, Metal, CUDA, Vulkan and other backends, a CLI and an OpenAI-compatible server

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

Open JSON-RPC standard for connecting AI applications to tools, data and prompts through servers, now stewarded under the Linux Foundation with SDKs in many languages

Open-source runtime and model manager for running open-weight LLMs locally on macOS, Windows and Linux, with a REST API, OpenAI- and Anthropic-compatible endpoints and optional cloud models

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

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