One API for all of US radio.

Every licensed US station, across AM, FM, LPFM, translator, and HD, resolves through one public endpoint to its identity, live now-playing, logo, and services. It resolves through to official radiodns.org and adds the AM / LPFM / translator layer they never covered. Free. CORS-open. No key. No signup. Build on it today.

01Try it live

This calls the real production API from your browser right now, the same requests your app will make. Pick an endpoint, edit the input, run it.

// pick an endpoint above and hit Run

02Resolve anything in one call

Give the resolver any bearer form: a coded FM/AM/HD name, an AM call sign, or a facility-<id> alias. Get back the normalized identity, live DNS status, the real SI service content, logo, and now-playing. Everything else is built on this.

# call sign, FM bearer, AM bearer, HD bearer, all resolve
curl "https://{host}/rdns/resolve?bearer=KAZM"
curl "https://{host}/rdns/resolve?bearer=10650.d4d2.da0.fm.radiodns.org"
curl "https://{host}/rdns/resolve?bearer=00780.1296.1a0.am.zerotrustradio.org"

From the browser, no key, no proxy

const r = await fetch(`https://{host}/rdns/resolve?bearer=${call}`);
const station = await r.json();
// station.identity, station.status, station.si_service?.logos,
// station.services, station.service_content, station.cname_target

03Drop-in widget & SDK

Add one script; render a live station card anywhere with a single attribute: logo, status, and a play button, isolated in Shadow DOM so it never fights your CSS.

<!-- once per page -->
<script src="https://{host}/static/uiq-embed.js" defer></script>

<!-- anywhere, as many as you like -->
<div data-uiq-station="KAZM"></div>
<div data-uiq-bearer="10650.d4d2.da0.fm.radiodns.org"></div>

Or drive it yourself. The same script exposes a tiny global:

UndertowIQ.resolve("KAZM").then(s => console.log(s.status));
UndertowIQ.mount(document.getElementById("slot"), "KAZM");
UndertowIQ.scan(container);  // (re)scan for data-uiq-* nodes

See the full widget with live demos on the Embed page.

04The receiver bridge

Here is the honest picture. A stock RadioDNS set builds a .radiodns.org bearer from the signal and does a DNS lookup, and for the ~40,000 US stations never registered there (and for all AM, which official RadioDNS never defined) that lookup returns nothing. You cannot reflash those sets. But any programmable receiver or app can call one endpoint with what it reads off-air and get the whole dial.

Give it the broadcast parameters. Get back the station. It builds the standard bearer, checks whether the station is registered on official radiodns.org, then falls back to our namespace, which covers every US station. Integrate once, support everything, not just the few registered officially.

# what a set reads off-air: PI, GCC (or ECC), frequency
GET /rdns/receiver/resolve?system=fm&pi=c460&gcc=ce1&freq=106.5
GET /rdns/receiver/resolve?system=am&pi=1296&ecc=a0&freq=780
GET /rdns/receiver/resolve?callsign=KAZM

# -> { bearer:{official, uiq}, official_radiodns:{registered},
#      source, station:{ logo_url, stream_url, now_playing{artwork_url}, services } }

Drop-in receiver SDK

One script gives you resolution plus a live receiver panel (logo, album art, now-playing, play), isolated in Shadow DOM. This is a working hybrid radio in three lines.

<script src="https://{host}/static/uiq-receiver.js"></script>

UIQReceiver.resolve({ system:'fm', pi:'c460', gcc:'ce1', freq:106.5 })
  .then(r => console.log(r.station, r.official_radiodns));

UIQReceiver.mount(document.getElementById('slot'), { callsign:'KAZM' });

05Why build on this

06Endpoint reference

Public, read-only, CORS *, cached ~60s. No authentication.

Build something with this? We want to hear about it. Get in touch.
More: The Standard · Embed & SDK · Lookup · Network · Our promise