API
All data on this site is also available in machine-readable form: postcode lookup, analysis results with full provenance and versioned parametric values — as JSON, read-only. The API primarily serves our own systems; external use is possible on request (free tier, 1,000 requests/day).
Request access
Briefly describe what you want to use the data for — we review the request and send the key by email, usually within a few working days.
Quickstart
curl "https://maunawai.info/v1/lookup?plz=50823" \
-H "X-Api-Key: mwi_..."Response: supply zones of the postcode with water supplier, area share and confidence. Values per zone: GET /v1/zones/{id}.
Endpoints
| Endpoint | Description | Access |
|---|---|---|
| GET /v1/lookup?plz= | Postcode → zones, water supplier, ambiguity | Key |
| GET /v1/zones/{id} | Zone: current values + classification against the parametric value + sources | Key |
| GET /v1/zones/{id}/measurements | All data points of a zone (time series, verbatim) | Key |
| GET /v1/suppliers/{id} | Water supplier + its zones | Key |
| GET /v1/parameters | Parameter register (282 parameters) | open |
| GET /v1/parameters/{code}/limits | Versioned parametric values (e.g. PFAS-20 from 12.01.2026) | Key |
| GET /v1/export/plz-zonen | Complete postcode↔zone mapping, JSON/CSV — ODbL | open |
| POST /v1/keys/antrag | Request access (review, key by email) | open |
Full reference with schemas: interactive docs (OpenAPI) · openapi.json
Licence
Open (ODbL): the postcode↔zone mapping (/v1/export/plz-zonen) is based on OpenStreetMap data and is licensed under the Open Database License v1.0 — attribution: “© maunawai.info / © OpenStreetMap contributors”.
Proprietary: the measured value database (analysis results, history, provenance). Use within the scope of the free tier; formal API terms will follow. All values come from the linked mandatory publications of the water suppliers and are not official.
Beta: endpoints may still change. Feedback welcome.