# polls.karbach.digital — Constituency Race Simulation

> polls.karbach.digital — Constituency Race Simulation is a paid API for AI agents from api.polls.karbach.digital, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-28).

Returns Monte-Carlo win probabilities, first-vote projections, and race ratings for a specific German Bundestag constituency based on 10,000 simulated scenarios.

## Facts

- Endpoint: GET https://api.polls.karbach.digital/v1/constituencies/%7Bnr%7D/race?utm_source=zero.xyz
- Price: $0.02/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-race-simulation-26bcc5a4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0ATpZlWyxf-wR5HiOMTMA

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-race-simulation-26bcc5a4
```

Example prompt: What are the win probabilities for each party in Bundestag constituency 299 — who is favoured to take the direct mandate and how safe is the seat?

## When to prefer this

Choose this endpoint when you need constituency-level (Wahlkreis) direct-mandate win probabilities and race ratings for German federal elections, backed by a calibrated Monte-Carlo model with 10,000 scenarios. Prefer this over national-level poll aggregators when the user's question is about a specific constituency's competitiveness, the favourite for the first vote (Erststimme), or the incumbent's chances — rather than national seat projections or coalition arithmetic.

## Known failure modes

- Invalid or out-of-range constituency number returns an error or empty response
- Constituency number not covered by the 18 simulated elections returns no data
- Stale data during the 6-hour refresh window — projections may lag very recent poll releases
- Rate limiting or payment failure if x402 micropayment is not processed correctly

## 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

A JSON object containing: win probabilities (0–1) for each party, first-vote percentage projections per party, the projected favourite, race rating (sicher/wahrscheinlich/umkämpft), expected margin in percentage points, incumbent party, state (Bundesland), election identifier, simulation metadata (n=10,000, method, sigma), data source attribution, and last-updated timestamp. Updated every 6 hours.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "state": "SL",
   "rating": "sicher",
   "election": "btw-2029",
   "favourite": "AfD",
   "constituency": 299,
   "incumbent_party": "CDU/CSU",
   "win_probability": {
    "AfD": 0.6933,
    "FDP": 0,
    "SPD": 0.1901,
    "Linke": 0.0002,
    "CDU/CSU": 0.1164
   },
   "first_vote_projection": {
    "AfD": 32.21,
    "FDP": 3.62,
    "SPD": 26.13,
    "Linke": 8.91,
    "CDU/CSU": 21.86
   },
   "expected_margin_points": 6.78
  },
  "docs": "https://api.polls.karbach.digital/v1/",
  "model": {
   "method": "MC-Sampling pro WK, n=10000 Iterationen, σ_total 4.08 Pp = √(UNS² 2.77 + Personen² 3.00) · Inkumbenz-Bonus +3.0 Pp auf den BTW-2025-Direktmandatsinhaber",
   "samples": 10000
  },
  "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",
   "polls_license_url": "https://opendatacommons.org/licenses/odbl/1-0/"
  },
  "project": "Ein Projekt von Karbach.Digital (https://karbach.digital)",
  "updated_at": "2026-10-18T12:55:10.873908",
  "uncertainty": "Win probabilities from simulation with correlated errors and per-party sigma; rating: sicher, wahrscheinlich, umkämpft."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polls-karbach-digital-constituency-race-simulation-26bcc5a4/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)