Directory

API-first US brokerage offering a Trading API, Market Data API and Broker API for stocks, ETFs, options and crypto, with paper trading

REST API for stock, ETF, options, forex, crypto, commodity and economic data plus fundamentals, news sentiment and technical indicators, with a free key tier and premium plans

Bloomberg's subscription workstation for market data, news, analytics, messaging and execution, with Excel integration and the BLPAPI library for C++, Java, .NET and Python

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

Usage-priced market data platform with normalized order-book (MBO/MBP), trades, OHLCV and reference schemas for futures, options and equities, delivered via historical, live and batch APIs in the DBN format

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

Vendor of historical intraday market data (1-minute to daily bars, tick and options) for US stocks, ETFs, futures, indices, crypto and FX, delivered as zipped CSV bundles under a perpetual licence

Hosting platform for open models, datasets and Spaces demo apps built on git repositories and Xet storage, with Inference Providers, Endpoints, Jobs and an open-source Python client and CLI

Programmatic trading and market-data access to Interactive Brokers accounts through the TWS API, the REST-based Web API and FIX

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

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

Algorithmic trading platform built on the open-source LEAN engine, with cloud backtesting, research notebooks and brokerage-connected live trading

Citation-analysis platform whose Smart Citations show whether later papers support, contrast or merely mention a claim, with an AI assistant and reference checking