Directory

Market data platform (renamed from Polygon.io in October 2025) with REST and WebSocket APIs, flat files and SQL access for US stocks, options, indices, forex, crypto and futures

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

Microsoft's subscription suite of Office desktop and web apps, Exchange email, OneDrive, SharePoint and Teams with Copilot and Graph APIs

Microsoft's public cloud with virtual machines, AKS, Azure Functions, Cosmos DB, Azure Database for PostgreSQL, Entra ID identity and Microsoft Foundry for hosted AI models

French model provider offering open-weight and proprietary models through the Studio API, OCR and speech models, the Vibe agent for productivity and coding, and self-deployment options

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

Nasdaq's marketplace for financial, economic and alternative datasets (formerly Quandl) with a REST API, time-series and table endpoints and Python, R and Excel clients

Hosted workspace combining block-based documents, relational databases, wikis and project views, with an API and built-in AI features

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

OpenAI's hosted developer platform: Responses and Chat Completions APIs, Realtime voice, embeddings, images, audio, fine-tuning, evals and managed agents

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

Unified API gateway to hundreds of models from many providers with automatic fallbacks, credit-based pass-through billing, BYOK, free models and data-policy routing

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

European cloud and hosting provider offering dedicated bare-metal servers, public and hosted private cloud, VPS, domains and web hosting from data centers in Europe, Canada and elsewhere

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

Commercial API platform for designing, testing, documenting and monitoring HTTP and other APIs through a desktop and web client with cloud-synced workspaces

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

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

Web scraping API with anti-bot bypass, JavaScript rendering, cloud browsers, screenshots, AI extraction and a crawler, billed in credits per request

The SEC's free public filing system: company and full-text search, bulk index and feed archives, and data.sec.gov JSON APIs for submissions and XBRL financial facts, subject to a fair-access rate policy