Spec

Code snippets

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

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

$ch = curl_init("https://api.oanor.com/runoff-api/v1/meta");
curl_setopt($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/runoff-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": "Runoff coefficient C is 0–1 (0.9 paved, 0.2 lawns). units: metric (mm/h, ha) or us (in/h, acres). Slope is m/m, length m, flows m³/s.",
        "service": "runoff-api",
        "formulae": {
            "kirpich": "tc(min) = 0.0195·L^0.77·S^(−0.385)",
            "rational_us": "Q(cfs) = C·i·A (i in/h, A acres)",
            "rational_metric": "Q(m³/s) = C·i·A/360 (i mm/h, A ha)"
        },
        "endpoints": {
            "GET /v1/meta": "This document.",
            "GET /v1/rational": "Peak runoff Q = C·i·A (metric or US units).",
            "GET /v1/detention": "Required detention storage from inflow peak, allowable outflow and duration.",
            "GET /v1/time-of-concentration": "Kirpich time of concentration from flow-path length and slope."
        },
        "description": "Stormwater-runoff calculator: peak runoff by the Rational Method, the time of concentration (Kirpich) and a first-order detention-storage estimate."
    },
    "meta": {
        "timestamp": "2026-06-05T11:30:26.447Z",
        "request_id": "e01ccc92-afa7-4748-9296-9b5dabab140a"
    },
    "status": "ok",
    "message": "Meta",
    "success": true
}