Spec

Extraits de code

curl "https://api.oanor.com/butterworth-api/v1/meta" \
  -H "x-oanor-key: oanor_test_..."

await fetch("https://api.oanor.com/butterworth-api/v1/meta", {
  headers: { "x-oanor-key": "oanor_test_..." }
});

$ch = curl_init("https://api.oanor.com/butterworth-api/v1/meta");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);

import requests
requests.get(
    "https://api.oanor.com/butterworth-api/v1/meta",
    headers={"x-oanor-key": "oanor_test_..."}
)

Exemple de réponse

Une réponse réelle de ce endpoint, capturée lors du dernier contrôle de santé.

{
    "data": {
        "notes": "Frequencies in Hz (or any consistent unit), attenuations and ripple in dB, order a positive integer. The Butterworth response is maximally flat in the passband with no ripple.",
        "service": "butterworth-api",
        "formulae": {
            "order": "n = ⌈log10((10^(As/10)−1)/(10^(Ap/10)−1)) / (2·log10(fs/fp))⌉",
            "poles": "s_k = ωc·exp(jπ(2k+n−1)/(2n))",
            "response": "|H| = 1/√(1 + (f/fc)^(2n))"
        },
        "endpoints": {
            "GET /v1/meta": "This document.",
            "GET /v1/order": "Minimum filter order from passband/stopband edges and attenuations.",
            "GET /v1/poles": "Left-half-plane pole locations of an n-th order Butterworth.",
            "GET /v1/response": "Magnitude (and dB) of an n-th order Butterworth at a frequency."
        },
        "description": "Butterworth filter calculator: the minimum order for a specification, the maximally-flat magnitude response, and the s-plane pole locations."
    },
    "meta": {
        "timestamp": "2026-06-05T11:30:23.183Z",
        "request_id": "900424a0-3bdc-493e-b7fc-2888a98067ec"
    },
    "status": "ok",
    "message": "Meta",
    "success": true
}