Letters, clearly composed.

Four ways to author

Use fluent Java, immutable Java values, strict JSON or letter HTML. Every route reaches the same PDF engine.

Built for real letters

Control stationery, pagination, rich tables, visible signatures, localization and reusable company styling.

See what you will get

Browse generated PDFs and previews. Download complete programs, template inputs and assets.

Know the boundaries

Find exact attributes, units, inheritance rules and rendering limits before integration.

A first letter, in your preferred API

Your API choice is remembered across documentation pages. Java examples below are complete programs; JSON and HTML show their complete input documents.

Fluent Java

import com.nsdev.lettergenerator.Letter;
import com.nsdev.lettergenerator.LetterPdfGenerator;
import java.nio.file.Files;
import java.nio.file.Path;

/** A complete first letter using the fluent API and engine-provided standard fonts. */
public final class FluentQuickstart {
    private FluentQuickstart() {}

    public static void main(String[] args) throws Exception {
        var letter = Letter.builder().body("Hello from Letter Generator").build();
        byte[] pdf = new LetterPdfGenerator().generate(letter);
        Files.write(Path.of(args.length == 0 ? "letter.pdf" : args[0]), pdf);
    }
}

Typed Java

import com.nsdev.lettergenerator.LetterPdfGenerator;
import com.nsdev.lettergenerator.model.LetterDocument;
import com.nsdev.lettergenerator.model.Section;
import com.nsdev.lettergenerator.model.block.Paragraph;
import com.nsdev.lettergenerator.model.text.TextRun;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

/** The same letter constructed directly from immutable public model values. */
public final class TypedQuickstart {
    private TypedQuickstart() {}

    public static void main(String[] args) throws Exception {
        var letter =
                new LetterDocument(
                        LetterDocument.SUPPORTED_SCHEMA_VERSION,
                        null,
                        null,
                        List.of(
                                new Section(
                                        "body",
                                        null,
                                        List.of(
                                                new Paragraph(
                                                        List.of(
                                                                new TextRun(
                                                                        "Hello from Letter Generator",
                                                                        null,
                                                                        null)),
                                                        null)))),
                        List.of(),
                        null,
                        null);
        byte[] pdf = new LetterPdfGenerator().generate(letter);
        Files.write(Path.of(args.length == 0 ? "letter.pdf" : args[0]), pdf);
    }
}

JSON

{
  "schemaVersion": 1,
  "sections": [{
    "name": "body",
    "blocks": [{
      "type": "paragraph",
      "runs": [{ "text": "Hello from Letter Generator" }]
    }]
  }]
}

HTML

<letter page="a4">
  <main>
    <p>${message}</p>
  </main>
</letter>

Continue by task

Choose the right APICompare authoring styles, template binding and model control.

Recreate the energy letterFollow one realistic, fictional letter through all four APIs.

Look up a tag or propertyFind supported markup, inline CSS and JSON fields.

Reuse a company themeStyle typography, stationery, tables and signatures consistently.