louislam/uptime-kuma · error · Error

Unsupported proxy protocol "${proxy.protocol}. Supported pro

Error message

Unsupported proxy protocol "${proxy.protocol}. Supported protocols are ${this.SUPPORTED_PROXY_PROTOCOLS.join(", ")}."

What it means

Thrown by Proxy.save when proxy.protocol is not in SUPPORTED_PROXY_PROTOCOLS = ['http','https','socks','socks5','socks5h','socks4']. Note the message string itself is malformed (misplaced quote and stray period): the user-facing text is `Unsupported proxy protocol "<protocol>. Supported protocols are http, https, socks, socks5, socks5h, socks4."` — a cosmetic bug, but the cause is clear.

Source

Thrown at server/proxy.js:35

     * @param {number} userID ID of user the proxy belongs to
     * @returns {Promise<Bean>} Updated proxy
     */
    static async save(proxy, proxyID, userID) {
        let bean;

        if (proxyID) {
            bean = await R.findOne("proxy", " id = ? AND user_id = ? ", [proxyID, userID]);

            if (!bean) {
                throw new Error("proxy not found");
            }
        } else {
            bean = R.dispense("proxy");
        }

        // Make sure given proxy protocol is supported
        if (!this.SUPPORTED_PROXY_PROTOCOLS.includes(proxy.protocol)) {
            throw new Error(`
                Unsupported proxy protocol "${proxy.protocol}.
                Supported protocols are ${this.SUPPORTED_PROXY_PROTOCOLS.join(", ")}."`);
        }

        // When proxy is default update deactivate old default proxy
        if (proxy.default) {
            await R.exec("UPDATE proxy SET `default` = 0 WHERE `default` = 1");
        }

        bean.user_id = userID;
        bean.protocol = proxy.protocol;
        bean.host = proxy.host;
        bean.port = proxy.port;
        bean.auth = proxy.auth;
        bean.username = proxy.username;
        bean.password = proxy.password;
        bean.active = proxy.active || true;
        bean.default = proxy.default || false;

View on GitHub (pinned to 6b5ea01557)

Solutions

1. Set proxy.protocol to one of the exact lowercase values: http, https, socks, socks5, socks5h, socks4.
2. If submitting via API, lowercase the value before sending (e.g. protocol.toLowerCase()).
3. Update the frontend dropdown to emit only the canonical lowercase values.
4. As a code fix, normalize case in Proxy.save before the includes() check and fix the broken quote in the error template.

Example fix

// before
if (!this.SUPPORTED_PROXY_PROTOCOLS.includes(proxy.protocol)) {
    throw new Error(`
        Unsupported proxy protocol "${proxy.protocol}.
        Supported protocols are ${this.SUPPORTED_PROXY_PROTOCOLS.join(", ")}."`);
}
// after (normalize case, fix the malformed message)
const protocol = (proxy.protocol || "").toLowerCase();
if (!this.SUPPORTED_PROXY_PROTOCOLS.includes(protocol)) {
    throw new Error(`Unsupported proxy protocol "${protocol}". Supported protocols are ${this.SUPPORTED_PROXY_PROTOCOLS.join(", ")}.`);
}

// Normalize and validate protocol before save
const protocol = (proxy.protocol || "").toLowerCase();
if (!Proxy.SUPPORTED_PROXY_PROTOCOLS.includes(protocol)) {
    throw new Error(`Unsupported proxy protocol "${protocol}". Supported: ${Proxy.SUPPORTED_PROXY_PROTOCOLS.join(", ")}`);
}

/** True when protocol is one of the supported lowercase schemes. */
function isSupportedProxyProtocol(protocol) {
    return typeof protocol === "string" &&
        ["http","https","socks","socks5","socks5h","socks4"].includes(protocol.toLowerCase());
}

if (!isSupportedProxyProtocol(proxy.protocol)) {
    throw new Error(`Unsupported proxy protocol "${proxy.protocol}". Supported: ${Proxy.SUPPORTED_PROXY_PROTOCOLS.join(", ")}`);
}

When it happens

Trigger: Empty protocol field, a capitalized value like 'HTTP' or 'SOCKS5' (the check is case-sensitive), a typo such as 'socks4a' or 'socks5H', or a frontend bug submitting the protocol label instead of its value.

Common situations: Manual API/DB edit setting protocol to an uppercase or unsupported scheme; older config using 'socks4a'; or a custom client sending the display name.

Related errors

• Unsupported recipient type: ${notification.threemaRecipientT
• Unsupported proxy protocol provided. ${proxy.protocol}
• Interval cannot be less than ${MIN_INTERVAL_SECOND} seconds
• Retry interval cannot be less than ${MIN_INTERVAL_SECOND} se
• Response max length cannot be less than 0

AI-assisted analysis of louislam/uptime-kuma@6b5ea01557 (2026-08-12). Data as JSON: /api/errors/7689d7f0c71e9bc8. Report an issue: GitHub.