The Public Library API for developers

Look up any US public library by address — with hours, services, collections, programs, and full system metadata. Clean JSON, built on the federal IMLS Public Libraries Survey. No scraping, no state-by-state portal hunting.

Get a free API keyRead the docs
curl "https://api.libraryapi.dev/v1/outlets?address=14901+Dale+Evans+Pkwy+Apple+Valley+CA&radius_miles=10" \
  -H "X-API-Key: lk_live_your_api_key"
{
  "data": [{
    "outletId": "CA0109-004",
    "name": "Newton T. Bass Apple Valley Branch Library",
    "outletType": "branch",
    "distanceMiles": 0.14,
    "hours": { "annualHours": 1520, "weeksOpen": 52 },
    "parentSystem": { "fscsId": "CA0109", "name": "San Bernardino County Library" }
  }],
  "meta": { "creditsUsed": 1, "creditsRemaining": 499 }
}

What you get

Address → nearest libraries
Geocoded radius search returns the closest outlets, ranked by distance.
Hours & services
Annual open hours, weeks open, and outlet-level service details.
Collections & programs
Print, ebook, and audio holdings plus program attendance and counts.
Systems & outlets
Both the administrative system and every physical outlet under it.
State & national rollups
Aggregate statistics by state for benchmarking and analysis.
Free public-domain data
IMLS PLS, refreshed annually. No licensing fees, no usage restrictions.

Why libraryapi.dev

The IMLS Public Libraries Survey is the authoritative national dataset — but it ships as annual CSV/SAS downloads with no geocoding and no address lookup. We normalize it, add PostGIS spatial search, and serve it as one clean API call. Address lookup and the full schema are on the free tier.

See pricing →

Frequently asked questions

How do I find libraries near an address?

Call GET /v1/outlets?address=…&radius_miles=… and the API geocodes the address and returns nearby public library outlets ordered by distance, with hours, services, and parent-system info.

What data source powers this API?

The IMLS Public Libraries Survey (PLS) — an annual federal census of every US public library system and outlet. It's public-domain data with no commercial-use restrictions.

Is there a free tier?

Yes — 500 requests/month, no credit card, full access to every endpoint and the complete response schema.

What's the difference between a library system and an outlet?

A system is the administrative entity (e.g. a county library); an outlet is a physical location — main library, branch, bookmobile, or books-by-mail. The API exposes both.

How many libraries are covered?

About 9,250 public library systems and 17,500+ outlets across all 50 states, DC, and the territories.

Start with 500 free requests/month

No credit card. Every endpoint, full schema, address lookup.

Get your API key