Feature

Public / No Authentication

Open endpoints callable without credentials.

14 providers 48 APIs 5 declared variants

At least some endpoints are usable with no key or token at all, which makes evaluation, prototyping, and open-data consumption immediate. Common across government and reference-data APIs.

14 API providers on the APIs.io network offer public / no authentication. The highest-rated are Agricultural Marketing Service, IOTA, U.S. Treasury Fiscal Data, Datamuse, PokéAPI.

Providers

Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.

Strong 1 Solid coverage with minor gaps
Agricultural Marketing Service The Agricultural Marketing Service (AMS), an agency of the United States Department of Agriculture (USDA), ... 3 APIs 61.1
Developing 4 Usable, with meaningful gaps to close
IOTA IOTA is an open-source distributed ledger technology built to bring real-world applications on-chain. It is... 9 APIs 53.0 U.S. Treasury Fiscal Data The U.S. Treasury Bureau of the Fiscal Service manages the government's finances including collecting reven... 1 API 52.0 Datamuse Datamuse operates a word-finding query engine and lexical search service for developers, educators, and cre... 1 API 51.6 PokéAPI PokéAPI (pokeapi.co) is a free, open-source RESTful and GraphQL API serving comprehensive Pokémon data — in... 2 APIs 45.8
Thin 9 Limited public surface area
Punk API Punk API is a free, no-auth REST API exposing BrewDog's "DIY Dog" open-source beer recipe collection — 325 ... 1 API 43.7 JSONPlaceholder JSONPlaceholder is a free, no-auth fake REST API for prototyping, tutorials, and testing. It exposes six re... 1 API 41.6 Studio Ghibli Studio Ghibli API — a community-built, unofficial, fan-made, MIT-licensed REST API that catalogs the people... 1 API 41.6 Frankfurter Frankfurter is an open-source (MIT) currency exchange rates API that blends foreign-exchange reference rate... 2 APIs 41.0 TIER TIER Mobility was a Berlin-headquartered shared electric micromobility operator founded in 2018 by Lawrence... 1 API 41.0 Ron Swanson Quotes A community-built, open source HTTP API that returns Ron Swanson quotes from the NBC television series Park... 1 API 38.2 VA Lighthouse VA Lighthouse is the US Department of Veterans Affairs' developer API platform. Published at developer.va.g... 23 APIs 37.4 Quote Garden Quote Garden is a free, open-source REST API that serves more than 75,000 famous quotes. Built by Prathames... 1 API 32.0 FakerAPI FakerAPI is a free, no-authentication REST API that returns realistic fake data for developers, designers, ... 1 API 30.7

What Providers Actually Declared

This feature is a canonical term. These are the free-text strings providers wrote in their own apis.yml that map onto it.

No API Key RequiredNo AuthenticationNo Authentication RequiredOpen, unauthenticated public data — no API key requiredOpen-data facilities, forms, and reference-data APIs (no auth required for read endpoints)

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