louislam/uptime-kuma · warning · Error

Invalid monitor ID

Error message

Invalid monitor ID

What it means

Thrown by the status badge route GET /api/badge/:id/status when `parseInt(request.params.id, 10)` returns NaN. The :id path parameter must be a base-10 integer; any non-numeric value (letters, empty, float-formatted) triggers it. The catch block passes the message to sendHttpError().

Source

Thrown at server/routers/api-router.js:168

    const {
        label,
        upLabel = "Up",
        downLabel = "Down",
        pendingLabel = "Pending",
        maintenanceLabel = "Maintenance",
        upColor = badgeConstants.defaultUpColor,
        downColor = badgeConstants.defaultDownColor,
        pendingColor = badgeConstants.defaultPendingColor,
        maintenanceColor = badgeConstants.defaultMaintenanceColor,
        style = badgeConstants.defaultStyle,
        value, // for demo purpose only
    } = request.query;

    try {
        const requestedMonitorId = parseInt(request.params.id, 10);
        if (Number.isNaN(requestedMonitorId)) {
            throw new Error("Invalid monitor ID");
        }
        const overrideValue = value !== undefined ? parseInt(value) : undefined;
        const publicMonitor = await isMonitorPublic(requestedMonitorId);
        const badgeValues = { style };

        if (!publicMonitor) {
            // return a "N/A" badge in naColor (grey), if monitor is not public / not available / non exsitant

            badgeValues.message = "N/A";
            badgeValues.color = badgeConstants.naColor;
        } else {
            const heartbeat = await Monitor.getPreviousHeartbeat(requestedMonitorId);
            const state = overrideValue !== undefined ? overrideValue : heartbeat.status;

            if (label === undefined) {
                badgeValues.label = "Status";
            } else {
                badgeValues.label = label;

View on GitHub (pinned to 6b5ea01557)

Solutions

1. Use the monitor's numeric ID from the dashboard in the badge URL.
2. Validate the :id segment is an integer before generating the badge link.
3. Check the rendered URL in the browser devtools for stray characters or empty segments.
4. If integrating programmatically, build the URL with a verified integer ID.

Example fix

// before
const url = `/api/badge/${monitorName}/status`;

// after
const url = `/api/badge/${Number(monitor.id)}/status`;

// Build the badge URL only with a verified integer ID
const id = Number(monitorId);
if (!Number.isInteger(id)) throw new Error('monitor id must be an integer');
const url = `/api/badge/${id}/status`;

function isValidMonitorId(id) {
  return Number.isInteger(Number(id)) && Number(id) > 0;
}

When it happens

Trigger: Requesting the status badge with a non-numeric monitor ID in the URL, e.g. /api/badge/abc/status or /api/badge//status, or passing a monitor slug/name instead of its numeric ID.

Common situations: Embedding the badge in a README/HTML with a placeholder or mistyped ID; using a monitor's name instead of its numeric ID; URL-encoding artifacts corrupting the segment.

Related errors

• The maximum number of hours is 720
• The maximum number of days is 365
• Invalid duration: ${duration}
• Invalid Docker response, is it Docker really a daemon?
• domain_expiry_unsupported_monitor_type

AI-assisted analysis of louislam/uptime-kuma@6b5ea01557 (2026-08-12). Data as JSON: /api/errors/27c7cb50dc0db8b7. Report an issue: GitHub.