Node

In Node, @laminapdf/sdk reads its .wasm files from the @laminapdf/wasm package as bytes. Call await init({ text: true }) once; after that, every call is synchronous.

This app builds one A4 page that says “Hello, world!” and writes it to hello.pdf:

packages/sdk/examples/quick-start/node.ts

// Builds a one-page PDF that says "Hello, world!" and writes it to hello.pdf, in Node.
import { writeFile } from "node:fs/promises";
import { Builder, type BuilderOptions, Font, init } from "@laminapdf/sdk";

/** The space between the page's edge and the text, in points (72 points = 1 inch). */
const MARGIN = 72;
/** The text's size in points; its baseline sits this far below the margin. */
const FONT_SIZE = 24;

/** Builds the page and hands its bytes to `save`, which writes hello.pdf unless you pass another `save` function. */
export async function hello(
  save: (pdf: Uint8Array) => void | Promise<void> = (pdf) => writeFile("hello.pdf", pdf),
  options: BuilderOptions = {},
): Promise<void> {
  await init({ text: true });
  using builder = new Builder(options);
  const page = builder.page("A4");
  // Points from the page's top-left corner, y down; the text's baseline sits FONT_SIZE points below the margin.
  page.surface().text("Hello, world!", {
    font: Font.standard("Helvetica"),
    size: FONT_SIZE,
    at: [MARGIN, MARGIN + FONT_SIZE],
  });
  page.finish();
  using doc = builder.finish();
  await save(doc.save());
}

// `node hello.ts` runs it (Node 24.2 or newer); imported, it only exports `hello`.
if (import.meta.main) await hello();

Save it as hello.ts in a project with @laminapdf/sdk installed, and run it with Node 24.2 or newer, which runs TypeScript files as they are:

node hello.ts

Node 22 can’t parse the using that frees the builder and the document, so compile the app with tsc first there. Lamina PDF’s tests run this app in Node 22 (compiled), 24 and 26 and check that it builds the reference PDF byte for byte.

A long-running server should free documents the same way; how Lamina PDF thinks about a PDF explains why.

Next: draw text with fonts, or open and edit a file.