Loc Plans Pricing
The Library of Congress APIs are free public services provided by the US federal government. There are no paid tiers or commercial plans. The loc.gov JSON API and Chronicling America API require no authentication and are completely free. The Congress.gov API requires a free API key obtained via api.congress.gov/sign-up/.
Loc Plans Pricing is the machine-readable pricing-plan profile for Library of Congress on the APIs.io network, conforming to the API Commons Plans specification.
It defines 3 plans, with named plans including loc.gov JSON API - Free Public Access, Chronicling America API - Free Public Access, Congress.gov API - Free API Key.
Tagged areas include Library, Government, Congress, Legislative Data, and Digital Collections.
Plans
No API key or authentication required. Open access to all Library of Congress digital collection endpoints. Intended for researchers, developers, and the general public.
No API key or authentication required. Open access to historic American newspapers data.
Free API key required. Sign up at api.congress.gov/sign-up/ using a Data.gov account. Provides access to all legislative data on Congress.gov.
Work with this as data
Every plan here is available over the APIs.io API and to AI agents over MCP.
MCP server
One button, every client — Claude, Cursor, VS Code and the rest.
https://apis.io/mcp
Tools for plans
4 MCP tools reach this
find_plansBrowse and filter every plan in the catalog.apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.resolveTurn a domain, URL or GitHub org into the provider it belongs to.find_cohortsEvery scored population of providers in the catalog.
Call it yourself
curl for this page
curl "https://apis.io/api/v1/plans/loc-plans-pricing"curl "https://apis.io/api/v1/plans?limit=25"Discovery needs no key. Ratings and market analysis are Pro.