@open-form/core

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

Fundamental package for modeling business documents as typed, versioned artifacts. Provides builders for Forms, Documents, Checklists, and Bundles with schema-driven validation and composition.

- 🏗️ Type-safe builders - Fluent API for defining document structures
- 📋 Four artifact types - Form, Document, Checklist, and Bundle builders
- ✅ Schema-driven validation - Built-in structure and constraint validation
- 🎯 Composable design - Reuse fields and artifacts across definitions
- 📦 Standalone library - Use independently or with @open-form/sdk

Installation

``bash
npm install @open-form/core
`

Usage

Define forms with parties, fields, and validation rules:

`typescript
import { open } from "@open-form/core";

const leaseAgreement = open
.form()
.name("residential-lease-agreement")
.version("1.0.0")
.title("Residential Lease Agreement")
.defaultLayer("markdown")
.layers({
markdown: open
.layer()
.file()
.mimeType("text/markdown")
.path("fixtures/lease-agreement.md"),
})
.parties({
landlord: open
.party()
.label("Landlord")
.signature({ required: true }),
tenant: open
.party()
.label("Tenant")
.multiple(true)
.min(1)
.max(4)
.signature({ required: true }),
})
.fields({
leaseId: { type: "uuid", label: "Lease ID" },
propertyAddress: {
type: "address",
label: "Property Address",
required: true,
},
monthlyRent: { type: "money", label: "Monthly Rent", required: true },
leaseStartDate: { type: "date", label: "Lease Start Date", required: true },
})
.build();
`

Add file attachments and advanced field types:

`typescript
const advancedLease = open
.form()
.name("commercial-lease")
.version("1.0.0")
.title("Commercial Lease Agreement")
.allowAdditionalAnnexes(true)
.annexes({
photoId: open.annex().title("Photo ID").required(true),
proofOfIncome: open.annex().title("Proof of Income").required(true),
})
.parties({
landlord: open
.party()
.label("Landlord")
.signature({ required: true }),
tenant: open
.party()
.label("Tenant")
.multiple(true)
.signature({ required: true }),
})
.fields({
leaseId: { type: "uuid", label: "Lease ID", required: true },
leaseTermMonths: {
type: "number",
label: "Lease Term (months)",
required: true,
},
monthlyRent: { type: "money", label: "Monthly Rent", required: true },
petPolicy: {
type: "enum",
enum: ["no-pets", "small-pets", "all-pets"],
label: "Pet Policy",
required: true,
},
})
.build();
`

Define static documents with metadata:

`typescript
const leadPaintDisclosure = open
.document()
.name("lead-paint-disclosure")
.version("1.0.0")
.title("Lead Paint Disclosure")
.code("EPA-747-K-12-001")
.releaseDate("2025-12-01")
.metadata({ agency: "EPA/HUD", cfr: "40 CFR 745" })
.layers({
pdf: open
.layer()
.file()
.path("fixtures/lead-paint-disclosure.pdf")
.mimeType("application/pdf"),
})
.defaultLayer("pdf")
.build();
`

Define workflow checklists with status tracking:

`typescript
const leaseChecklist = open
.checklist()
.name("lease-application-checklist")
.version("1.0.0")
.title("Lease Application Checklist")
.items([
{
id: "application_received",
title: "Application Received",
status: { kind: "boolean" },
},
{
id: "credit_check",
title: "Credit Check Complete",
status: { kind: "boolean" },
},
{
id: "background_check",
title: "Background Check Complete",
status: { kind: "boolean" },
},
{ id: "lease_signed", title: "Lease Signed", status: { kind: "boolean" } },
])
.build();
`

Compose artifacts into bundles:

`typescript
const propertyAddress = {
type: "address",
label: "Property Address",
required: true,
};
const monthlyRent = { type: "money", label: "Monthly Rent", required: true };

const residentialLease = open
.form()
.name("residential-lease")
.version("1.0.0")
.fields({ leaseId: { type: "uuid" }, propertyAddress, monthlyRent })
.build();

const commercialLease = open
.form()
.name("commercial-lease")
.version("1.0.0")
.fields({ leaseId: { type: "uuid" }, propertyAddress, monthlyRent })
.build();

const leaseBundle = open
.bundle()
.name("residential-lease-bundle")
.version("1.0.0")
.contents([
{ type: "inline", key: "residential", artifact: residentialLease.toJSON({ includeSchema: false }) },
{ type: "inline", key: "commercial", artifact: commercialLease.toJSON({ includeSchema: false }) },
{ type: "inline", key: "disclosure", artifact: leadPaintDisclosure.toJSON({ includeSchema: false }) },
{ type: "inline", key: "checklist", artifact: leaseChecklist.toJSON({ includeSchema: false }) },
])
.build();
`

Extract TypeScript types from artifacts:

`typescript
import { type InferFormPayload } from "@open-form/core";

type LeaseData = InferFormPayload;

const data: LeaseData = {
fields: {
leaseId: "550e8400-e29b-41d4-a716-446655440000",
propertyAddress: {
line1: "123 Main St",
locality: "Portland",
region: "OR",
postalCode: "97201",
country: "USA",
},
monthlyRent: { amount: 1500, currency: "USD" },
leaseStartDate: "2024-02-01",
},
};
`

Validate and fill forms with data:

`typescript
// Check if the form schema itself is valid
if (!leaseAgreement.isValid()) {
console.log("Form schema is invalid");
}

// Fill the form with data (validates during fill)
try {
const filled = leaseAgreement.fill(data);
console.log("Form filled successfully");
} catch (error) {
console.error("Validation failed:", error);
}

// Or use safeFill to avoid exceptions
const result = leaseAgreement.safeFill(data);
if (result.success) {
const filled = result.data;
} else {
console.error("Validation failed:", result.error);
}
`

For rendering artifacts to PDF, DOCX, HTML, or other formats, use @open-form/sdk with the renderers package. For complete production examples, see /incubator/apps/demo/src/demos/leasing. For API reference and advanced patterns, visit docs.open-form.dev.

Changelog

View the Changelog for updates.

Related packages

- @open-form/sdk - Complete framework with renderers
- @open-form/types - TypeScript utilities and types
- @open-form/schemas - JSON Schema definitions
- @open-form/renderers - All renderers (PDF, DOCX, Text)
- @open-form/resolvers` - File and environment resolvers

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.