ZUGFeRD and Factur-X API

curl -sS https://klarbon.app/api/v1/convert \
  -H "Authorization: Bearer $KLARBON_API_KEY" \
  -H "Idempotency-Key: invoice-123456XX-zugferd" \
  -F "file=@invoice.xml;type=application/xml" \
  -F target=zugferd \
  -o result.json
jq -e '.ok' result.json > /dev/null || { jq -r '.error + ": " + .message' result.json; exit 1; }
jq -r '.file.content' result.json | base64 --decode > "$(jq -r '.file.filename' result.json)"

import { readFile, writeFile } from "node:fs/promises"

type KlarbonFile = { content: string; filename: string; mime: string; bytes: number }
type Failure = { ok: false; error: string; message: string }
type Converted = { ok: true; file: KlarbonFile; credits: { spent: number; balance: number } }

const form = new FormData()
form.append("file", new Blob([await readFile("invoice.xml")], { type: "application/xml" }), "invoice.xml")
form.append("target", "zugferd")

const response = await fetch("https://klarbon.app/api/v1/convert", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.KLARBON_API_KEY}`,
    "Idempotency-Key": "invoice-123456XX-zugferd",
  },
  body: form,
})
const result = (await response.json()) as Converted | Failure
if (!result.ok) throw new Error(`${response.status} ${result.error}: ${result.message}`)
await writeFile(result.file.filename, Buffer.from(result.file.content, "base64"))
console.log(`${result.file.filename} written, ${result.credits.balance} credits left`)

import base64
import os

import requests

with open("invoice.xml", "rb") as upload:
    response = requests.post(
        "https://klarbon.app/api/v1/convert",
        headers={
            "Authorization": f"Bearer {os.environ['KLARBON_API_KEY']}",
            "Idempotency-Key": "invoice-123456XX-zugferd",
        },
        files={"file": ("invoice.xml", upload, "application/xml")},
        data={"target": "zugferd"},
        timeout=120,
    )
result = response.json()
if not result["ok"]:
    raise SystemExit(f"{response.status_code} {result['error']}: {result['message']}")
with open(result["file"]["filename"], "wb") as output:
    output.write(base64.b64decode(result["file"]["content"]))
print(result["file"]["filename"], "written,", result["credits"]["balance"], "credits left")

<?php
$curl = curl_init('https://klarbon.app/api/v1/convert');
curl_setopt_array($curl, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT => 120,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . getenv('KLARBON_API_KEY'),
        'Idempotency-Key: invoice-123456XX-zugferd',
    ],
    CURLOPT_POSTFIELDS => [
        'file' => new CURLFile('invoice.xml', 'application/xml', 'invoice.xml'),
        'target' => 'zugferd',
    ],
]);
$body = curl_exec($curl);
if ($body === false) {
    fwrite(STDERR, curl_error($curl) . "\n");
    exit(1);
}
$result = json_decode($body, true);
if (!$result['ok']) {
    $status = curl_getinfo($curl, CURLINFO_RESPONSE_CODE);
    fwrite(STDERR, "$status {$result['error']}: {$result['message']}\n");
    exit(1);
}
file_put_contents($result['file']['filename'], base64_decode($result['file']['content']));
echo "{$result['file']['filename']} written, {$result['credits']['balance']} credits left\n";

using System.Net.Http.Headers;
using System.Text.Json;

using var http = new HttpClient();
var key = Environment.GetEnvironmentVariable("KLARBON_API_KEY");
http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", key);

var upload = new ByteArrayContent(await File.ReadAllBytesAsync("invoice.xml"));
upload.Headers.ContentType = new MediaTypeHeaderValue("application/xml");

using var request = new HttpRequestMessage(HttpMethod.Post, "https://klarbon.app/api/v1/convert?target=zugferd") { Content = upload };
request.Headers.Add("Idempotency-Key", "invoice-123456XX-zugferd");
using var response = await http.SendAsync(request);
using var json = JsonDocument.Parse(await response.Content.ReadAsStringAsync());
var result = json.RootElement;
if (!result.GetProperty("ok").GetBoolean())
{
    Console.Error.WriteLine($"{(int)response.StatusCode} {result.GetProperty("error")}: {result.GetProperty("message")}");
    return 1;
}
var written = result.GetProperty("file");
await File.WriteAllBytesAsync(written.GetProperty("filename").GetString()!,
    Convert.FromBase64String(written.GetProperty("content").GetString()!));
Console.WriteLine($"{written.GetProperty("filename")} written, {result.GetProperty("credits").GetProperty("balance")} credits left");
return 0;