Spec

Code snippets

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

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

$ch = curl_init("https://api.oanor.com/helmholtz-api/v1/meta");
curl_setopt($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/helmholtz-api/v1/meta",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "notes": "Core endpoints use SI (area m², length m, volume m³); port-tuning uses practical audio units (box litres, port cm). Default speed of sound 343 m/s. neck_type: flanged, unflanged, flanged-unflanged (default) or none.",
        "service": "helmholtz-api",
        "formulae": {
            "volume": "V = A·c² / (L_eff·ω²)",
            "frequency": "f = (c/2π)·√(A/(V·L_eff))",
            "effective_length": "L_eff = L_neck + end_correction·radius"
        },
        "constants": {
            "speed_of_sound_ms": 343
        },
        "endpoints": {
            "GET /v1/meta": "This document.",
            "GET /v1/design": "Cavity volume needed to tune a resonator to a target frequency.",
            "GET /v1/frequency": "Resonant frequency from neck area/diameter, neck length, cavity volume and end correction.",
            "GET /v1/port-tuning": "Bass-reflex port: tuning frequency from port length, or port length for a target frequency."
        },
        "description": "Helmholtz resonator acoustics: resonant frequency from neck and cavity geometry, cavity sizing for a target frequency, and bass-reflex (vented speaker box) port tuning."
    },
    "meta": {
        "timestamp": "2026-06-05T11:30:36.725Z",
        "request_id": "1c40ec69-4110-4264-91ca-dd41ebb31677"
    },
    "status": "ok",
    "message": "Meta",
    "success": true
}