# polls.karbach.digital — Constituency Lookup by Postcode

> polls.karbach.digital — Constituency Lookup by Postcode is a paid API for AI agents from api.polls.karbach.digital, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-28).

Returns the German Bundestag constituency associated with a given postcode, including links to detailed race and simulation data.

## Facts

- Endpoint: GET https://api.polls.karbach.digital/v1/constituencies/by-postcode/%7Bplz%7D?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polls-karbach-digital-constituency-lookup-by-postcode-085ebceb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VVkPEJMsKjWjSMo0ysqhS

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 polls-karbach-digital-constituency-lookup-by-postcode-085ebceb
```

Example prompt: Which German Bundestag constituency does postcode 10115 belong to, and where can I get more details about the election simulation for that district?

## When to prefer this

Use this endpoint when you need to resolve a German postcode (PLZ) to its corresponding Bundestag constituency number and name, especially as a precursor to fetching detailed election simulation data from the race or detail sibling endpoints. Prefer this over manual lookup tables when you need a programmatic, up-to-date mapping with direct links to Monte-Carlo simulation results.

## Known failure modes

- Postcode does not exist or is invalid — likely returns an error or empty result
- Postcode crosses multiple constituency borders — endpoint returns the main/primary constituency only, which may not represent a minority of addresses in that postcode
- Stale data if the 6-hour refresh cycle has not yet run
- Postcode outside Germany — no match possible

## How this service works

Unabhängige Wahlsimulation für 18 deutsche Wahlen. Monte-Carlo-Modell mit 10.000 Szenarien pro Wahl, kalibriert und intern validiert an 34 historischen Wahlen (Leave-One-Out, MAE ±1.27 Pp). Alle 6 Stunden aktualisiert.

## Output

Returns a JSON object with the constituency name, number, state code (e.g. 'SL'), the postcode queried, a URL to the detailed constituency race simulation, and a URL to the full constituency detail endpoint. Also includes metadata such as source attribution (dawum.de polls, ODbL 1.0 license), update timestamp, and a notice that results are scenario analysis, not predictions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "name": "Homburg",
   "note": "Postcodes can cross constituency borders; this is the main constituency of the postcode.",
   "race": "https://api.polls.karbach.digital/v1/constituencies/299/race",
   "state": "SL",
   "detail": "https://api.polls.karbach.digital/v1/constituencies/299",
   "postcode": "66453",
   "constituency": 299
  },
  "docs": "https://api.polls.karbach.digital/v1/",
  "model": null,
  "notice": "Scenario analysis based on published opinion polls. Not a prediction and not a voting recommendation. Coalitions are arithmetic majorities only, not statemen...",
  "source": {
   "polls": "dawum.de",
   "processing": "polls.karbach.digital (Max Karbach)",
   "polls_license": "ODbL 1.0",
   "postcode_mapping": "polls.karbach.digital",
   "polls_license_url": "https://opendatacommons.org/licenses/odbl/1-0/"
  },
  "project": "Ein Projekt von Karbach.Digital (https://karbach.digital)",
  "updated_at": "2026-10-18T15:28:17.464793",
  "uncertainty": null
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polls-karbach-digital-constituency-lookup-by-postcode-085ebceb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.polls.karbach.digital](https://www.zero.xyz/host/api.polls.karbach.digital/llms.txt)