Track Record

{
  "data": {
    "backtest_34_elections": {
      "baseline_poll_avg_5_mae": {
        "mean_mae": 1.3,
        "n": 34
      },
      "brier": 0.0711,
      "ci95_hit": 96.9,
      "mae": 1.27,
      "methodology": "v4.16 — punkt=weighted-poll-avg-fenster5 (CLR-sim nur fuer verteilung/CI/sitze/koalitionen; ablation A6/A7 2026-06-10) + per-partei-sigma + party-correlation...",
      "n_wahlen": 34,
      "updated_at": "2026-10-18 04:30:24",
      "winner_correct": 31,
      "winner_total": 34
    },
    "description": "Forecasts frozen eight days before the election, measured against official results.",
    "elections_2026": [
      {
        "actual": {
          "AfD": 43.8,
          "BSW": 5.3,
          "CDU": 17.2,
          "FDP": 2.6,
          "Grüne": 8.9,
          "Linke": 8.6,
          "SPD": 9.3
        },
        "date": "2026-09-06",
        "eid": "st-2026",
        "frozen_date": "2026-08-28",
        "im_band": 5,
        "mae": 2.47,
        "name": "Landtagswahl Sachsen-Anhalt",
        "parteien": 7,
        "sieger_stimmt": true,
        "v4_frozen": {
          "AfD": 42.3,
          "BSW": 4.1,
          "CDU": 22.1,
          "FDP": 3.3,
          "Grüne": 5.3,
          "Linke": 12,
          "SPD": 7.3
        }
      },
      {
        "actual": {
          "AfD": 16.3,
          "BSW": 4.7,
          "CDU": 18.8,
          "FDP": 2.5,
          "Grüne": 14.3,
          "Linke": 25.7,
          "SPD": 12.1
        },
        "date": "2026-09-20",
        "eid": "be-2026",
        "frozen_date": "2026-09-11",
        "im_band": 7,
        "mae": 1.74,
        "name": "Abgeordnetenhaus Berlin",
        "parteien": 7,
        "sieger_stimmt": true,
        "v4_frozen": {
          "AfD": 18,
          "BSW": 3.8,
          "CDU": 19.9,
          "FDP": 3.3,
          "Grüne": 16.1,
          "Linke": 20.2,
          "SPD": 12.5
        }
      }
    ],
    "summary_2026": {
      "im_band": 17,
      "mae": 2.17,
      "sieger": 3,
      "slots": 21,
      "wahlen": 3
    }
  },
  "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...",
  "project": "Ein Projekt von Karbach.Digital (https://karbach.digital)",
  "source": {
    "polls": "dawum.de",
    "polls_license": "ODbL 1.0",
    "polls_license_url": "https://opendatacommons.org/licenses/odbl/1-0/",
    "processing": "polls.karbach.digital (Max Karbach)"
  },
  "uncertainty": null,
  "updated_at": "2026-10-19"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://api.polls.karbach.digital/v1/track-record'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://api.polls.karbach.digital/v1/track-record' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.01 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.01" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.01 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.polls.karbach.digital%2Fv1%2Ftrack-record
const res = await pay("https://api.polls.karbach.digital/v1/track-record");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.01 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.01"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://api.polls.karbach.digital/v1/track-record")
    print(res.status_code, res.text)