What causes "Category "${category}" not found" in DIYgod/RSSHub?

Verify the slug against GET /wp-json/wp/v2/categories on the TFC Taiwan site and use the exact slug.

DIYgod/RSSHub · warning · InvalidParameterError

Category "${category}" not found

Error message

Category "${category}" not found

What it means

First of two category-not-found guards in the TFC Taiwan category route. After querying the WordPress REST API (wp-json/wp/v2/categories) filtered by slug, if the response is an array but empty, the slug matched no category and InvalidParameterError is thrown. This covers the slug-lookup path (isNumericCategory false).

Source

Thrown at lib/routes/tfc-taiwan/category.ts:19

import InvalidParameterError from '@/errors/types/invalid-parameter';
import type { Route } from '@/types';
import ofetch from '@/utils/ofetch';

import { baseUrl, parseItem, parsePost } from './utils';

const handler = async (ctx) => {
    const { category } = ctx.req.param();
    const limit = ctx.req.query('limit') ? Number(ctx.req.query('limit')) : undefined;
    const isNumericCategory = !Number.isNaN(Number(category));

    const categoryResponse = await ofetch(`${baseUrl}/wp-json/wp/v2/categories${isNumericCategory ? `/${category}` : ''}`, {
        query: {
            slug: isNumericCategory ? undefined : category,
        },
    });

    if (Array.isArray(categoryResponse) && !categoryResponse.length) {
        throw new InvalidParameterError(`Category "${category}" not found`);
    }
    const categoryInfo = isNumericCategory ? categoryResponse : categoryResponse[0];
    if (!categoryInfo.id) {
        throw new InvalidParameterError(`Category "${category}" not found`);
    }

    const postsResponse = await parsePost(limit, categoryInfo.id);
    const items = parseItem(postsResponse);

    return {
        title: categoryInfo.yoast_head_json.title,
        description: categoryInfo.yoast_head_json.og_site_name,
        image: categoryInfo.yoast_head_json.og_image[0].url,
        logo: categoryInfo.yoast_head_json.og_image[0].url,
        icon: categoryInfo.yoast_head_json.og_image[0].url,
        link: categoryInfo.link,
        lang: 'zh-TW',
        item: items,

View on GitHub (pinned to bed535e087)

Solutions

Verify the slug against GET /wp-json/wp/v2/categories on the TFC Taiwan site and use the exact slug.
Use the numeric category id instead of the slug (the route accepts numeric values).
Confirm the category still exists (it may have been merged/deleted).

Example fix

// before
if (Array.isArray(categoryResponse) && !categoryResponse.length) {
    throw new InvalidParameterError(`Category "${category}" not found`);
}

// after: hint at the lookup endpoint in the message
if (Array.isArray(categoryResponse) && !categoryResponse.length) {
    throw new InvalidParameterError(`Category slug "${category}" not found. Verify at ${baseUrl}/wp-json/wp/v2/categories`);
}

Defensive patterns

Strategy: validation

Validate before calling

async function categorySlugExists(baseUrl: string, slug: string): Promise<boolean> {
    const r = await ofetch(`${baseUrl}/wp-json/wp/v2/categories`, { query: { slug } });
    return Array.isArray(r) && r.length > 0;
}
// pre-check before calling the handler's fetch

Type guard

function isNonEmptyCategoryArray(r: unknown): r is { id: number; slug: string }[] {
    return Array.isArray(r) && r.length > 0;
}

Try / catch

try {
    return await handler(ctx);
} catch (e) {
    if (e instanceof InvalidParameterError && /Category .* not found/.test(e.message)) {
        return notFound(`Category "${ctx.req.param('category')}" does not exist`);
    }
    throw e;
}

Prevention

Verify the category slug against /wp-json/wp/v2/categories before subscribing.
Prefer the numeric category id when available to avoid slug-typo failures.
Watch for category renames/deletions on the source site.

When it happens

Trigger: Requesting /tfc-taiwan/category/<slug> where <slug> is non-numeric and does not match any category slug; the REST API returns HTTP 200 with an empty array [] because the slug is unknown.

Common situations: Typo in the category slug; the category was renamed/removed; user copied a category name instead of its slug.

Related errors

AI-assisted analysis of DIYgod/RSSHub@bed535e087 (2026-08-12). Data as JSON: /api/errors/96215e24684a30ed. Report an issue: GitHub.