OpenForm is documents as code. It lets developers and AI agents define, validate, and render business documents using typed, composable schemas. This eliminates template drift, broken mappings, and brittle glue code — while giving AI systems a reliable document layer they can safely read, reason over, and generate against in production workflows.

Package overview

Renders OpenForm documents to PDF format with automatic field type detection and serialization.

• Automatic field serialization - Detects field types (Money, Person, Phone, Address, Organization) from form schema and automatically formats them
• PDF form filling - Fill PDF form fields with dynamic data
• Field inspection - Inspect available form fields in PDF templates
• Binary output - Returns Uint8Array for direct file writing or streaming
• Type-safe - Full TypeScript support with OpenForm core types

Installation

npm install @open-form/renderer-pdf

Usage

Direct Rendering with renderPdf()

Render PDF templates directly with automatic field serialization:

import { renderPdf } from "@open-form/renderer-pdf";
import fs from "node:fs";
import { petAddendumForm } from "./forms/pet-addendum";

const template = fs.readFileSync("pet-addendum.pdf");

const output = await renderPdf(
  new Uint8Array(template),
  petAddendumForm,
  {
    petName: {
      firstName: "Fluffy",
      lastName: "Whiskers",
      fullName: "Fluffy Whiskers",
    },
    monthlyFee: {
      amount: 100,
      currency: "USD",
    },
  }
);

// output is Uint8Array - write to file
fs.writeFileSync("output.pdf", output);

renderPdf() Parameters:

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | template | BinaryContent | Yes | PDF template as binary | | form | Form | Yes | Form definition containing field schemas | | data | Record<string, unknown> | Yes | Data object to populate form fields | | bindings | Record<string, string> | No | Optional mapping from PDF field names to form field names | | serializers | SerializerRegistry | No | Custom serializer registry (defaults to USA serializers) |

Returns: Promise<BinaryContent> - Rendered PDF as binary

Using the Form Builder API

Render PDF using the OpenForm builder pattern with method chaining:

import { pdfRenderer } from "@open-form/renderer-pdf";
import { createFsResolver } from "@open-form/resolvers/fs";
import { petAddendumForm } from "./forms/pet-addendum";

const resolver = createFsResolver({ root: "./templates" });

const output = await petAddendumForm
  .fill({
    fields: {
      petName: {
        firstName: "Fluffy",
        lastName: "Whiskers",
        fullName: "Fluffy Whiskers",
      },
      monthlyFee: {
        amount: 100,
        currency: "USD",
      },
    },
  })
  .render({
    renderer: pdfRenderer,
    layer: "pdf",
    resolver,
  });

// output is Uint8Array

pdfRenderer Instance:

| Property | Type | Description | |----------|------|-------------| | id | string | Renderer identifier: "pdf" | | render() | function | Async render function accepting RenderRequest |

Form .render() Parameters:

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | renderer | OpenFormRenderer | Yes | Renderer instance (pdfRenderer) | | layer | string | Yes | Name of the template layer to render | | resolver | FileResolver | No | File resolver for loading template files |

Returns: Promise<BinaryContent> - Rendered PDF as binary

Changelog

View the Changelog for updates.

Related packages

• @open-form/sdk - OpenForm framework SDK
• @open-form/renderers - All renderers in one package

Contributing

We're open to all community contributions! If you'd like to contribute in any way, please read our contribution guidelines and code of conduct.

License

This project is licensed under the MIT license.

See LICENSE for more information.

Acknowledgments

Built with these excellent libraries:

• pdf-lib - Create and modify PDF documents