Duden APIduden.de ↗
Look up German verb conjugations, part of speech, and corpus frequency from Duden. Covers all moods and tenses via a single endpoint.
What is the Duden API?
The Duden.de API exposes 1 endpoint — get_conjugation — that returns full conjugation tables for any German verb across five grammatical moods, along with part of speech and Duden corpus frequency. A single call to get_conjugation with a verb like gehen or sein returns structured tables keyed by mood and tense, making it straightforward to build German language tools, grammar checkers, or learning apps without manually parsing Duden's dictionary.
curl -X GET 'https://api.parse.bot/scraper/ea3b0ee0-daeb-4252-931c-e1cc412af61c/get_conjugation?verb=gehen' \ -H 'X-API-Key: $PARSE_API_KEY'
Typed, relational, agent-ready
A generated client with real types, enums, and the links between objects — the structure a flat JSON response can't carry. Autocompletes in your editor and reads cleanly to coding agents.
- Fully typed · autocompletes
- Objects link to objects
- Typed errors & pagination
Typed Python client. Set up the SDK in your uv project, then pull this API’s typed client:
uv add parse-sdk uv run parse init uv run parse add --marketplace duden-de-api
uv run parse add --marketplace pulls a pinned snapshot of this canonical API — it won’t change underneath you. To customize it, subscribe and swap to your own copy.
"""Walkthrough: Duden Verb Conjugation SDK — look up conjugation tables for German verbs."""
from parse_apis.duden_verb_conjugation_api import Duden, Conjugation, VerbNotFound
client = Duden()
# Fetch conjugation for a common irregular verb
conj = client.conjugations.get(verb="gehen")
print(f"Verb: {conj.verb}, Type: {conj.wortart}")
# Access the konjugation dict — keys are moods, values are lists of TenseEntry
for mood, entries in conj.konjugation.items():
print(f" Mood: {mood}, Tenses: {len(entries)}")
break # just show first mood
# Handle a verb that doesn't exist in the database
try:
client.conjugations.get(verb="xyznotaverb")
except VerbNotFound as exc:
print(f"Not found: {exc.verb}")
# Fetch an ambiguous verb (multiple meanings) — resolves automatically
sein = client.conjugations.get(verb="sein")
print(f"Verb: {sein.verb}, Type: {sein.wortart}, Frequency: {sein.haeufigkeit}")
print("exercised: conjugations.get (regular verb / not-found error / ambiguous verb)")
Get conjugation data for a German verb from duden.de. Returns conjugation tables organized by mood (Indikativ, Konjunktiv I, Konjunktiv II, Imperativ, Infinite Formen) and tense. For ambiguous verbs with multiple meanings (e.g. 'sein', 'haben'), the scraper automatically resolves to the first available conjugation entry.
| Param | Type | Description |
|---|---|---|
| verbrequired | string | The German verb to conjugate (e.g. 'gehen', 'machen', 'sein'). |
{
"type": "object",
"fields": {
"verb": "string — the queried verb",
"wortart": "string or null — part of speech (e.g. 'unregelmäßiges Verb', 'schwaches Verb')",
"haeufigkeit": "string or null — frequency description from Duden corpus",
"konjugation": "object — conjugation tables keyed by mood (Indikativ, Konjunktiv I, Konjunktiv II, Imperativ, Infinite Formen), each containing an array of tense entries with tempus and formen fields"
},
"sample": {
"data": {
"verb": "gehen",
"wortart": "unregelmäßiges Verb",
"haeufigkeit": null,
"konjugation": {
"Imperativ": [
{
"formen": {
"2. Person Plural [ihr]": "geht!",
"2. Person Singular [du]": "geh, gehe!"
}
}
],
"Indikativ": [
{
"formen": {
"du": "gehst",
"ich": "gehe",
"ihr": "geht",
"sie": "gehen (sich)",
"wir": "gehen",
"er/sie/es": "geht (sich)"
},
"tempus": "Präsens"
}
],
"Infinite Formen": [
{
"formen": [
"zu gehen"
],
"bezeichnung": "Infinitiv mit zu"
}
]
}
},
"status": "success"
}
}About the Duden API
What the API Returns
The get_conjugation endpoint accepts a single required parameter — verb (string) — and returns a JSON object with four top-level fields: verb, wortart, haeufigkeit, and konjugation. The wortart field carries the grammatical classification from Duden, such as unregelmäßiges Verb (irregular verb) or schwaches Verb (weak verb). The haeufigkeit field reflects the frequency descriptor assigned by the Duden corpus, useful for distinguishing common vocabulary from rare forms.
Conjugation Table Structure
The konjugation object is keyed by grammatical mood: Indikativ, Konjunktiv I, Konjunktiv II, Imperativ, and Infinite Formen. Each mood key maps to an object of tense keys (e.g. Präsens, Präteritum, Perfekt), and each tense maps to person-indexed forms. This mirrors how Duden presents conjugation tables — organized first by mood, then by tense, covering both finite and non-finite forms.
Handling Ambiguous Verbs
High-frequency verbs like sein and haben have multiple dictionary entries on Duden. The API automatically resolves ambiguous verbs to their primary verb meaning, so you consistently receive a complete conjugation table rather than an error or partial response. No additional disambiguation parameter is needed from the caller.
The Duden API is a managed, monitored endpoint for duden.de — not a raw scraper you maintain. Every endpoint is automatically health-checked on a schedule, and when duden.de changes and a check fails, the API is automatically queued for repair and re-verified. It is built to keep working as the site underneath it changes.
This isn't an official duden.de API — it's an independent, maintained REST wrapper over public data. Where the source has no official API (or only a limited one), Parse gives you a stable contract over a source that never promised one, and keeps it current. Need a new endpoint or field? You can revise it yourself in plain English and the agent rebuilds it against the live site in minutes — contributing the change back to the shared API is free.
Will this API break when the source site changes?+
Is this an official API from the source site?+
Can I fix or extend this API myself if I need a new endpoint or field?+
What happens if I call an endpoint that has an issue?+
- Populate conjugation tables in a German language learning app using the
konjugationobject keyed by mood and tense - Flag irregular verbs in a grammar checker by reading the
wortartfield forunregelmäßiges Verb - Sort vocabulary lists by usage frequency using the
haeufigkeitcorpus descriptor - Generate grammar exercises for all six persons across
Indikativ PräsensandKonjunktiv IIforms - Build an autocomplete tool that shows correctly conjugated verb forms as a user types
- Cross-reference Duden part-of-speech data against other German NLP datasets using the
wortartfield
| Tier | Price | Credits/month | Rate limit |
|---|---|---|---|
| Free | $0/mo | 100 | 5 req/min |
| Hobby | $30/mo | 1,000 | 20 req/min |
| Developer | $100/mo | 5,000 | 100 req/min |
One credit = one API call regardless of which marketplace API you call. Exceeding the rate limit returns a 429 response. Authenticate with the X-API-Key header.
Does Duden offer an official developer API?+
What does `get_conjugation` return for the mood 'Infinite Formen'?+
Infinite Formen key in the konjugation object contains non-finite verb forms such as the infinitive, present participle (Partizip I), and past participle (Partizip II). These are returned under their standard German tense labels, consistent with how Duden presents them.Does the API cover noun declensions or adjective comparisons?+
Are all German verbs covered, including separable and reflexive verbs?+
aufgehen) and reflexive verbs listed on Duden should return results. Highly obscure or archaic verbs not indexed by Duden will return null fields or an empty conjugation object. The verb field in the response always echoes back the queried input so you can confirm what was looked up.Does the API return example sentences or definitions alongside conjugation data?+
wortart, haeufigkeit, and the konjugation table. Definitions, usage examples, and synonyms are not part of the current response shape. You can fork this API on Parse and revise it to capture those additional Duden dictionary sections.