API documentation

Quickstart

From zero to your first call in three steps.

1. Create a test key

   Sign in (free, only an email code) and create a key in your account under “API keys”. Choose a test key: it is free, limited to 20 calls per day and files up to 5 MB.

   Open API keys

2. Store the key

   Keep the key in an environment variable instead of in your code:

   export OWT_KEY=owk_test_...

3. Build and run your call

   Choose a tool below, copy the call and run it. The result is the processed file (or, for check tools, a JSON report).

curl -X POST 'https://wandlix.com/api/v1/tools/merge-pdf' \
  -H "Authorization: Bearer $OWT_KEY" \
  -F 'files=@file1.pdf' \
  -F 'files=@file2.pdf' \
  -OJ

Access

Create an API key in your account and send it in the Authorization header with every request. Go to your account

Authorization: Bearer owk_YOUR_KEY

An invalid or revoked key is rejected (HTTP 401) – never treated as a guest. Keep keys out of public code, browser programs and repositories.

Test keys

Keys starting with owk_test_ are free and never touch your balance. They are meant for trying out your integration and are limited to 20 calls per day and files up to 5 MB. After that you get HTTP 402 (quota_exceeded).

In your account you can set your own limit of requests per minute for each key; it then replaces the per-IP limit.

Request

One request per job, as multipart/form-data. Files stay in memory only and are discarded after the response.

POST https://wandlix.com/api/v1/tools/<tool>
Content-Type: multipart/form-data

• files – one or more files; the order is the processing order
• options – optional, JSON text with the tool’s options (see the table below)

Tools that take no files (for example qr-code and create-einvoice) also accept Content-Type: application/json with the body {"options": {…}}. That helps with clients that cannot send form uploads, such as online curl services.

curl

curl -X POST "https://wandlix.com/api/v1/tools/merge-pdf" \
  -H "Authorization: Bearer $OWT_KEY" \
  -F "files=@a.pdf" -F "files=@b.pdf" \
  -o merged.pdf

curl -X POST "https://wandlix.com/api/v1/tools/compress-image" \
  -H "Authorization: Bearer $OWT_KEY" \
  -F "files=@photo.png" \
  -F 'options={"quality":70,"maxWidth":1600}' \
  -o photo-small.png

JavaScript (Node.js)

const form = new FormData();
form.append("files", new Blob([await fs.readFile("a.pdf")]), "a.pdf");
form.append("files", new Blob([await fs.readFile("b.pdf")]), "b.pdf");

const res = await fetch("https://wandlix.com/api/v1/tools/merge-pdf", {
  method: "POST",
  headers: { Authorization: "Bearer " + process.env.OWT_KEY },
  body: form,
});
if (!res.ok) throw new Error((await res.json()).error);
await fs.writeFile("merged.pdf", Buffer.from(await res.arrayBuffer()));

Python

import os, requests

res = requests.post(
    "https://wandlix.com/api/v1/tools/merge-pdf",
    headers={"Authorization": "Bearer " + os.environ["OWT_KEY"]},
    files=[("files", open("a.pdf", "rb")), ("files", open("b.pdf", "rb"))],
)
res.raise_for_status()
open("merged.pdf", "wb").write(res.content)

PHP

$ch = curl_init("https://wandlix.com/api/v1/tools/merge-pdf");
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ["Authorization: Bearer " . getenv("OWT_KEY")],
    CURLOPT_POSTFIELDS => [
        "files[0]" => new CURLFile("a.pdf"),
        "files[1]" => new CURLFile("b.pdf"),
    ],
    CURLOPT_RETURNTRANSFER => true,
]);
file_put_contents("merged.pdf", curl_exec($ch));

Response

On success (HTTP 200) you get the result file, or a ZIP when there are several result files. The file name is in the Content-Disposition header, extra details in the X-Result-Info header (URL-encoded JSON).

The e-invoice check returns JSON with the check report under result instead.

Tools and options

The tool identifier goes into the URL. Options you leave out use their default.

Usage and limits

Every call is charged to your account – just like on the website.

• Your account’s daily free quota applies first.
• After that credits are deducted (the month’s free credits first, then purchased ones). The cost per tool is shown in your account.
• Failed calls cost nothing.
• At most 15 requests per minute per IP address; beyond that you get HTTP 429.

Errors

Errors come as JSON with an error field and the matching HTTP status.

HTTP 402
{"error":"quota_exceeded"}

Privacy

The API works exactly like the website: processing in Germany, files in memory only, deleted after an hour at the latest, no logging of file names or contents.