Deutsche IBAN prüfen und den BIC aus dem Bundesbank-Register holen, in Python und JavaScript

import os
import requests
 
API = os.environ.get("IBANFORGE_API", "https://api.ibanforge.com")
KEY = os.environ.get("IBANFORGE_KEY")  # optional for one IBAN, required for a batch
 
 
def headers() -> dict:
    h = {"Content-Type": "application/json"}
    if KEY:
        h["Authorization"] = f"Bearer {KEY}"
    return h
 
 
def raise_for_quota(r: requests.Response) -> None:
    if r.status_code == 429:
        raise RuntimeError(f"Too many requests: retry in {r.headers.get('Retry-After', '60')} s")
    if r.status_code == 402:
        raise RuntimeError("No allowance left: take a key, claim it, or add credits")
    r.raise_for_status()
 
 
def decide(a: dict) -> dict:
    """Turn one answer of the API into what the payment run does next."""
    if not a.get("valid"):
        return {"iban": a.get("iban"), "decision": "reject", "why": a.get("error")}
    check = a.get("bank_code_check") or {}
    bic = a.get("bic") or {}
    if check.get("reason") == "not_allocated" and check.get("authoritative"):
        return {"iban": a["iban"], "decision": "block",
                "why": f"{check['value']} is not in {check['register']} ({check['as_of']})"}
    if check.get("retired"):
        return {"iban": a["iban"], "decision": "update",
                "why": f"{check['value']} is being retired", "successor": check.get("superseded_by")}
    if check.get("status") == "verified" and check.get("authoritative"):
        return {"iban": a["iban"], "decision": "accept",
                "bank": check["institution"]["name"], "bic": bic.get("code"),
                "bic_basis": bic.get("basis"), "as_of": check.get("as_of")}
    return {"iban": a["iban"], "decision": "review", "why": check.get("status")}
 
 
def check_german_iban(iban: str) -> dict:
    r = requests.post(f"{API}/v1/iban/validate", json={"iban": iban}, headers=headers(), timeout=10)
    raise_for_quota(r)
    return decide(r.json())
 
 
def check_many(ibans: list) -> list:
    """Up to 100 IBANs per call; one request per IBAN is billed to the key."""
    out = []
    for i in range(0, len(ibans), 100):
        r = requests.post(f"{API}/v1/iban/batch", json={"ibans": ibans[i:i + 100]},
                          headers=headers(), timeout=30)
        raise_for_quota(r)
        out.extend(decide(a) for a in r.json()["results"])
    return out

const API = process.env.IBANFORGE_API ?? "https://api.ibanforge.com";
const KEY = process.env.IBANFORGE_KEY; // optional for one IBAN, required for a batch
 
function headers() {
  const h = { "Content-Type": "application/json" };
  if (KEY) h.Authorization = `Bearer ${KEY}`;
  return h;
}
 
async function readOrThrow(res) {
  if (res.status === 429) throw new Error(`Too many requests: retry in ${res.headers.get("Retry-After") ?? 60} s`);
  if (res.status === 402) throw new Error("No allowance left: take a key, claim it, or add credits");
  if (!res.ok) throw new Error(`IBANforge answered ${res.status}`);
  return res.json();
}
 
/** Turn one answer of the API into what the payment run does next. */
export function decide(a) {
  if (!a.valid) return { iban: a.iban, decision: "reject", why: a.error };
  const check = a.bank_code_check ?? {};
  const bic = a.bic ?? {};
  if (check.reason === "not_allocated" && check.authoritative) {
    return { iban: a.iban, decision: "block", why: `${check.value} is not in ${check.register} (${check.as_of})` };
  }
  if (check.retired) {
    return { iban: a.iban, decision: "update", why: `${check.value} is being retired`, successor: check.superseded_by };
  }
  if (check.status === "verified" && check.authoritative) {
    return { iban: a.iban, decision: "accept", bank: check.institution.name, bic: bic.code, bic_basis: bic.basis, as_of: check.as_of };
  }
  return { iban: a.iban, decision: "review", why: check.status };
}
 
export async function checkGermanIban(iban) {
  const res = await fetch(`${API}/v1/iban/validate`, {
    method: "POST",
    headers: headers(),
    body: JSON.stringify({ iban }),
    signal: AbortSignal.timeout(10_000),
  });
  return decide(await readOrThrow(res));
}
 
/** Up to 100 IBANs per call; one request per IBAN is billed to the key. */
export async function checkMany(ibans) {
  const out = [];
  for (let i = 0; i < ibans.length; i += 100) {
    const res = await fetch(`${API}/v1/iban/batch`, {
      method: "POST",
      headers: headers(),
      body: JSON.stringify({ ibans: ibans.slice(i, i + 100) }),
      signal: AbortSignal.timeout(30_000),
    });
    const { results } = await readOrThrow(res);
    out.push(...results.map(decide));
  }
  return out;
}

{"iban": "DE65100700000123456789", "decision": "accept", "bank": "Deutsche Bank", "bic": "DEUTDEBBXXX", "bic_basis": "national_register", "as_of": "2026-09"}
{"iban": "DE94140510000123456789", "decision": "accept", "bank": "Sparkasse Mecklenburg-Nordwest", "bic": "NOLADE21WIS", "bic_basis": "national_register", "as_of": "2026-09"}
{"iban": "DE22130610880123456789", "decision": "update", "why": "13061088 is being retired", "successor": "13061078"}
{"iban": "DE58123456780123456789", "decision": "block", "why": "12345678 is not in Deutsche Bundesbank Bankleitzahlendatei (2026-09)"}
{"iban": "DE65100700000123456798", "decision": "reject", "why": "checksum_failed"}

{
  "iban": "DE65100700000123456789",
  "valid": true,
  "bank_code_check": {
    "value": "10070000",
    "status": "verified",
    "match": "register",
    "register": "Deutsche Bundesbank Bankleitzahlendatei",
    "authoritative": true,
    "institution": {
      "name": "Deutsche Bank",
      "street": null,
      "post_code": "10883",
      "town": "Berlin",
      "country": "DE"
    },
    "as_of": "2026-09"
  },
  "bic": {
    "code": "DEUTDEBBXXX",
    "bank_name": "Deutsche Bank",
    "source": "Deutsche Bundesbank Bankleitzahlendatei",
    "as_of": "2026-09",
    "basis": "national_register",
    "authoritative": true
  },
  "trial": {
    "calls_used_this_week": 9,
    "calls_left_this_week": 16,
    "weekly_limit": 25,
    "resets": "Monday 00:00 UTC",
    "resets_at": "2026-10-05T00:00:00Z"
  }
}