Directory

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

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

Collaboratively edited world map database released under the ODbL, with planet files, an editing API and derived tiles and extracts

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

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

Canada's national statistical agency publishing census, economic and social data tables with open licensing and programmatic access via Web Data Service

Utility-first CSS framework from Tailwind Labs that styles markup with composable class names and generates only the CSS a project uses

Cloud platform for open-source models: serverless and dedicated inference, fine-tuning, GPU clusters, batch jobs and code sandboxes behind an OpenAI-compatible API

Hosted embedding and reranking models for retrieval, including code, finance, law and multimodal variants, offered by MongoDB with a free token allowance and pay-as-you-go API

ML experiment tracking, sweeps, artifacts and model registry plus Weave for LLM tracing and evaluation, now sold by CoreWeave within its Forge platform with a free academic tier

Institution-subscribed research data platform from Wharton hosting CRSP, Compustat, TAQ, OptionMetrics and dozens of other vendors' databases with web queries, SQL, SAS, Python and R access

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