# Open Trivia DB - All Question Categories

> Open Trivia DB - All Question Categories is a paid API for AI agents from clonecho.builda.company, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Returns the complete list of Open Trivia Database question categories with their numeric IDs

## Facts

- Endpoint: POST https://clonecho.builda.company/x402/s/opentdb-categories
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/open-trivia-db-all-question-categories-4044bd33
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gJB5lPFISu1tUQW3nZ3of

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability open-trivia-db-all-question-categories-4044bd33 -d '<json body>'
```

Example prompt: Can you get me the full list of trivia question categories from the Open Trivia Database, including their category IDs, so I can pick one for my quiz app?

## When to prefer this

Use this endpoint when you need to programmatically discover all available Open Trivia Database question categories and their numeric IDs, especially before constructing a filtered trivia question request that requires a category_id parameter. Ideal when building quiz apps or fetching trivia by topic.

## Known failure modes

- Upstream OpenTDB API unavailable — returns error or empty response
- Payment not processed — x402 payment required before data is returned
- Network timeout reaching the clonecho proxy

## How this service works

All Open Trivia Database question categories with ids (no params). Returns JSON.

## Output

A JSON object containing an array of trivia category objects, each with a numeric category ID and a category name string (e.g. {id: 9, name: 'General Knowledge'}). Covers all categories available in the Open Trivia Database.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/open-trivia-db-all-question-categories-4044bd33/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from clonecho.builda.company](https://www.zero.xyz/host/clonecho.builda.company/llms.txt)