What causes "Invalid user" in DIYgod/RSSHub?

Supply a non-empty Medium username in the URL, e.g. /medium/feed/johndoe.

DIYgod/RSSHub · error · InvalidParameterError

Invalid user

Error message

Invalid user

What it means

Thrown as an InvalidParameterError when the 'user' path parameter is falsy. The route /medium/feed/:user requires a non-empty username, so this guards against requests where the user segment is missing or empty.

Source

Thrown at lib/routes/medium/feed.ts:36

        supportPodcast: false,
        supportScihub: false,
    },
    radar: [
        {
            source: ['medium.com/@:user'],
            target: '/feed/:user',
        },
    ],
    name: 'Medium Feed',
    maintainers: ['pseudoyu'],
    handler,
};

async function handler(ctx) {
    const user = ctx.req.param('user');

    if (!user) {
        throw new InvalidParameterError('Invalid user');
    }

    const feed = await parser.parseURL(`https://medium.com/feed/@${user}`);

    return {
        title: feed.title ?? 'Medium',
        description: feed.description ?? `${user}'s Medium`,
        link: feed.link ?? `https://medium.com/@${user}`,
        image: feed.image?.url ?? '',
        item: feed.items.map((item) => ({
            title: item.title ?? 'Untitled',
            description: item['content:encoded'] ?? item.content ?? '',
            link: item.link ?? '',
            pubDate: item.pubDate ? parseDate(item.pubDate) : undefined,
            guid: item.guid ?? '',
            author: item.creator ?? user,
        })),
    };

View on GitHub (pinned to bed535e087)

Solutions

Supply a non-empty Medium username in the URL, e.g. /medium/feed/johndoe.
If building the URL programmatically, validate the user variable is a non-empty string before constructing the path.
Do not include the leading @ in some configurations — confirm the expected format.
Check that no URL shortener or rewrite rule strips the final path segment.

Example fix

// before
const url = `/medium/feed/${user}`; // user === ''

// after
if (!user) throw new Error('user required');
const url = `/medium/feed/${user}`;

Defensive patterns

Strategy: validation

Validate before calling

const user = ctx.req.param('user');
if (!user || typeof user !== 'string' || !user.trim()) {
    throw new InvalidParameterError('Medium username required');
}

Type guard

function isNonEmptyUser(user: unknown): user is string {
    return typeof user === 'string' && user.trim().length > 0;
}

Prevention

Validate path params at the route entry, before any network call.
Add a route-level regex constraint so empty users never reach the handler.

When it happens

Trigger: A request to the Medium feed route where ctx.req.param('user') returns an empty string or undefined — e.g. a malformed URL like /medium/feed/ or /medium/feed (with the segment stripped by a proxy).

Common situations: Misconfigured RSS reader with an empty Medium handle; URL-rewriting proxy dropping the trailing segment; typo where the user segment is blank; radar rule mismatch producing an empty capture.

Related errors

AI-assisted analysis of DIYgod/RSSHub@bed535e087 (2026-08-12). Data as JSON: /api/errors/c894107af9e4bd7c. Report an issue: GitHub.