by Maciej Dzierżek · published Apr 24, 2026 · updated May 15, 2026 · 15 min read · Beginner

Migrating from OpenTDB#

QuizBase is designed for drop-in migration from Open Trivia DB. The endpoints, fields, and category ids map cleanly — most existing clients need only two changes.

The two changes#

Base URL: https://opentdb.com/api.php → https://quizbase.runriva.com/api/v1/questions/random
Add auth: X-API-Key: qb_pk_* header

That’s it for the happy path. The response shape is different — see below — but the semantics are identical.

Field mapping (question)#

OpenTDB field	QuizBase field	Notes
`category` (string)	`category.name` + `category.slug` + `category.id`	QuizBase returns a nested object. `category.id` equals the OpenTDB numeric id when applicable.
`type`	`type`	Same enum: `multiple`, `boolean`. QuizBase adds `text_input`.
`difficulty`	`difficulty`	Extended enum: `trivial`, `easy`, `medium`, `hard`, `expert` — LLM-calibrated with distractor-set context. OpenTDB’s 3 levels map roughly to QuizBase `easy`/`medium`/`hard`; pre-rescore records hold an importer placeholder (mostly `medium`).
`question`	`text`	Renamed — `question` → `text`.
`correct_answer`	`correctAnswer`	camelCase.
`incorrect_answers`	`incorrectAnswers`	camelCase.
—	`language`	New — ISO 639-1. OpenTDB is English-only.
—	`id`	New — UUID v7. Use for caching/dedup.
—	`attribution`	New — `{ source, author, license, licenseUrl, url, sourceId }`. Mandatory to preserve (CC-BY-SA chain).
—	`tags`, `subcategories`	New — filter-friendly metadata. Both arrays of `{ slug, label }`: `slug` is the stable filter key (kebab-case), `label` is the human-readable string in the requested `?lang=`. Tags are short concept identifiers, subcategories are broader topic groupings.
—	`regions`	New — array of cultural affinity codes (lowercase ISO 3166-1 alpha-2 + `jewish` / `christian-catholic` / `islam`). Empty array = universally accessible. See /docs/api/regions.

Envelope mapping#

OpenTDB	QuizBase
`response_code`	❌ removed — use HTTP status codes + RFC 9457 error body
`results[]`	`data[]`
—	`meta: { count, requestId, language }`

OpenTDB’s response_code: 1/2/3/4/5 (no results / invalid param / token not found / token empty / rate limit) maps to:

OpenTDB code	QuizBase response
`0` (success)	`200` + `data` populated
`1` (no results)	`200` + `data: []`
`2` (invalid param)	`400` + RFC 9457 with `errors[]`
`3/4` (session token)	❌ not applicable — use `exclude=<ids>` for de-dup
`5` (rate limit)	`429` + `Retry-After` header

Category ids#

OpenTDB uses numeric ids 9–32. QuizBase preserves those same ids on the category.id field, so you can pass either the numeric id or our slug — both work:

# OpenTDB-style numeric id
curl -H "X-API-Key: qb_pk_YOUR_KEY" 
     "https://quizbase.runriva.com/api/v1/questions/random?amount=5&category=22"

# QuizBase slug
curl -H "X-API-Key: qb_pk_YOUR_KEY" 
     "https://quizbase.runriva.com/api/v1/questions/random?amount=5&category=geography"

Call GET /v1/categories once and build your id↔slug map.

Side-by-side diff#

Session tokens (OpenTDB) → `exclude` (QuizBase)#

OpenTDB’s session-token system (codes 3/4) prevents repeats in a session. QuizBase replaces it with explicit exclude:

# Fetch 5 questions, excluding those you've already shown
curl -H "X-API-Key: qb_pk_YOUR_KEY" 
     "https://quizbase.runriva.com/api/v1/questions/random?amount=5&exclude=id1,id2,id3"

Max 100 ids per request. Track them client-side.

Rate limits#

OpenTDB is “don’t abuse” without headers. QuizBase uses IETF RateLimit-* headers on every response — measure yourself and respect Retry-After on 429. See Rate limits and retries.