Java

HTML to PDF in Java

One POST, a PDF back. No headless browser to install, no Chromium to keep patched, no fonts to install on the box — the render happens on a warm browser that is already running.

Render HTML to a PDF

import java.net.URI;
import java.net.http.*;
import java.nio.file.Path;
import java.time.Duration;

var body = """
    {"html":"<h1>Invoice 1042</h1>","options":{"printBackground":true}}
    """;

var request = HttpRequest.newBuilder(URI.create("https://api.pdfcraft.dev/v1/render"))
    .header("Authorization", "Bearer " + System.getenv("PDFCRAFT_API_KEY"))
    .header("Content-Type", "application/json")
    .timeout(Duration.ofSeconds(60))
    .POST(HttpRequest.BodyPublishers.ofString(body))
    .build();

var client = HttpClient.newHttpClient();
var response = client.send(request, HttpResponse.BodyHandlers.ofFile(Path.of("invoice.pdf")));

if (response.statusCode() != 200) {
    throw new IllegalStateException("render failed: " + response.statusCode());
}

Read a PDF back as JSON

The same key works for extraction. Send a PDF, name the fields you want by the label printed on the page, and get them back with the raw text, a coerced value, a confidence and a bounding box.

var encoded = Base64.getEncoder().encodeToString(Files.readAllBytes(Path.of("statement.pdf")));
var payload = new ObjectMapper().writeValueAsString(Map.of(
    "file", encoded,
    "schema", Map.of("account_number", "string", "closing_balance", "currency")
));

var request = HttpRequest.newBuilder(URI.create("https://api.pdfcraft.dev/v1/extract"))
    .header("Authorization", "Bearer " + System.getenv("PDFCRAFT_API_KEY"))
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString(payload))
    .build();

var response = client.send(request, HttpResponse.BodyHandlers.ofString());
var json = new ObjectMapper().readTree(response.body());
System.out.println(json.at("/fields/closing_balance/value"));

What bites in Java

`BodyHandlers.ofFile` streams the response straight to disk without ever holding the PDF in the heap. For a large render that is the difference between a few kilobytes of buffer and a heap spike.
`Base64.getEncoder()`, not `getMimeEncoder()` — the MIME encoder line-wraps.
HttpClient is thread-safe and expensive to build. Make one and reuse it; a client per request defeats connection pooling and is the usual cause of "it is slower from Java".

Errors are one shape

Every failure is {"error":{"code","message","docs_url"}} with a stable code, so you can switch on error.code rather than parsing prose. The two worth handling explicitly are rate_limited — honour Retry-After — and render_failed, which means your HTML broke rather than ours did.

The same thing in another language

Or try it with no code at all in the playground. A free key is 100 renders a month.