GET https://api.grizzlybulls.com/v1/aircraft/icao24/{hex} accepts one exact six-digit hex address and returns the same reviewed current-aircraft response as N-number lookup. It does not return ADS-B positions, flight data, transponder-assignment history, or global aircraft coverage.
The open-source Aircraft Registry Explorer includes an ICAO24 lookup form. The hosted demo uses a separate server credential with abuse limits, so you do not need to enter a customer API key in your browser.
A12239 is an example request shape. The API accepts exactly six hexadecimal characters (0–9 and A–F), trims surrounding whitespace, accepts lowercase, and normalizes to uppercase.
A 0x prefix, octal values, wildcards, partial addresses, ranges, and fuzzy lookups are not accepted.
An N-number identifies a U.S. registration; ICAO24 / Mode S is an assigned surveillance address. Neither is a permanent physical-airframe identity. A current registry match is not proof of beneficial economic ownership.
How the identifiers relate →Keep GRIZZLY_BULLS_API_KEY in your trusted command-line or server environment and send it using Bearer authentication. Browser CORS is not enabled. These examples use cURL, Python 3, or server-side Node.js 18+.
curl --fail-with-body \
-H "Authorization: Bearer $GRIZZLY_BULLS_API_KEY" \
"https://api.grizzlybulls.com/v1/aircraft/icao24/A12239"import json
import os
import urllib.request
request = urllib.request.Request(
"https://api.grizzlybulls.com/v1/aircraft/icao24/A12239",
headers={"Authorization": f"Bearer {os.environ['GRIZZLY_BULLS_API_KEY']}"},
)
with urllib.request.urlopen(request) as response:
record = json.load(response)["data"]
print(record["registration"]["nNumber"])
print(record["aircraft"]["modeSCodeHex"])
print(record["source"]["retrievedAt"])const response = await fetch(
"https://api.grizzlybulls.com/v1/aircraft/icao24/A12239",
{ headers: { Authorization: "Bearer " + process.env.GRIZZLY_BULLS_API_KEY } },
);
if (!response.ok) throw new Error("Aircraft lookup failed: " + response.status);
const { data } = await response.json();
console.log(data.registration.nNumber, data.aircraft.modeSCodeHex);
console.log(data.source.retrievedAt);The example address illustrates request syntax, not a guaranteed permanent current match. A valid hex address missing from the reviewed current FAA registry returns 404 not_found.
data.registration.nNumber, data.aircraft.modeSCodeHex, manufacturer, model and serial number come from the existing AircraftCurrentResponse schema, not a second ICAO24 data model.
data.source.retrievedAt tells you which accepted FAA snapshot supplied the answer. data.history summarizes retained observations, not the legal time of a registration or ownership transfer.
Registrant details are subject to current FAA releasability. Retained history cannot restore names or addresses now withheld by the public source.
Invalid hex input returns 400 invalid_request before usage reservation. A missing or invalid key returns 401 unauthenticated. A valid address without a current match returns 404 not_found. Like N-number lookup, this uses the current_lookup request quota. Respect Retry-After on 429 rate_limited and use bounded retries on temporary 503 service_unavailable responses.
Free includes 1,000 requests per month and 30 requests per minute.
Use exact registration lookup when you already have a U.S. tail number.
Read the N-number lookup guide →Use observed change events and paid watch lists rather than interpreting one current lookup as a history.
Read the changes and webhooks guide →Make an exact lookup from your server and inspect the returned N-number, aircraft fields and accepted source timestamp before choosing a paid plan.