Quick start — Hosted API

From account to first PDF in five steps.

1. Create a free account

Go to app.rendarium.com/register, enter an email and a password (10 characters minimum) and accept the terms. A confirmation email arrives within a minute; the link is valid for 24 hours. Until you click it the account exists but has no key and no credits.

2. Copy your API key

Confirming the email creates your first API key (labelled default) and grants the Free plan: 100 credits for the first month, refilled on the same day every month. Sign in and open the Dashboard — the key is shown once, in full, with a Copy button:

rnd_live_k7m2p9x4a1b8c3d6e5f0g7h2j9k4m1n8

Save it now. We store only a SHA-256 hash: a lost key cannot be recovered or re-sent, only revoked and replaced from the API Keys page (your credits are not affected). Keep it out of public repositories, client-side code and logs.

3. Send the first request

Every call is an HTTPS request with the key as a Bearer token. Convert an HTML string to PDF:

curl -X POST https://api.rendarium.com/convert/html \
  -H "Authorization: Bearer rnd_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"html": "<h1>Invoice #1024</h1>"}' \
  --output invoice.pdf

using var http = new HttpClient();
http.DefaultRequestHeaders.Authorization = new("Bearer", "rnd_live_YOUR_KEY");
var body = JsonContent.Create(new { html = "<h1>Invoice #1024</h1>" });
var response = await http.PostAsync(
    "https://api.rendarium.com/convert/html", body);
await File.WriteAllBytesAsync("invoice.pdf",
    await response.Content.ReadAsByteArrayAsync());

import requests

response = requests.post(
    "https://api.rendarium.com/convert/html",
    headers={"Authorization": "Bearer rnd_live_YOUR_KEY"},
    json={"html": "<h1>Invoice #1024</h1>"},
)
open("invoice.pdf", "wb").write(response.content)

var request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.rendarium.com/convert/html"))
    .header("Authorization", "Bearer rnd_live_YOUR_KEY")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString(
        "{\"html\": \"<h1>Invoice #1024</h1>\"}"))
    .build();
HttpClient.newHttpClient().send(request,
    HttpResponse.BodyHandlers.ofFile(Path.of("invoice.pdf")));

const response = await fetch("https://api.rendarium.com/convert/html", {
  method: "POST",
  headers: {
    "Authorization": "Bearer rnd_live_YOUR_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ html: "<h1>Invoice #1024</h1>" }),
});
await fs.writeFile("invoice.pdf", Buffer.from(await response.arrayBuffer()));

A successful response has status 200, Content-Type: application/pdf and the PDF bytes as the body. Errors are JSON with an error code — see the full list.

4. Check the dashboard

The balance now reads 99 and the conversion table shows one row: timestamp, operation convert_html, key label, status succeeded, duration. Every request you make from now on appears here; failed ones show failed and cost nothing.

5. Go further

• Convert other formats — Word, Excel, Markdown, URLs — with the same key: API reference.
• Use a client library instead of raw HTTP.
• Create separate keys per environment (max 10 active) and watch per-key usage.
• At 80% of your monthly credits you receive an email; at 100% the API returns 429 quota_exceeded until you top up, upgrade on the billing page or your allowance resets.