📄 contract-js

PDF Contract Generation with Digital Signatures

A comprehensive TypeScript library for generating PDF contracts from EJS templates with digital signature support.

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🎯 Purpose

Generate professional PDF contracts from EJS templates with complete digital signature workflow including key generation, signing, and verification.

⌨️ CLI

@contract-js/cli

Command Line Interface for Contract Generation

A powerful CLI tool for generating PDF contracts from EJS templates with complete digital signature workflow.

• Contract Generation – Generate PDF contracts from EJS templates
• Digital Signing – Create digital signatures for PDF contracts
• Signature Verification – Verify digital signatures against PDF hashes
• File Hashing – Generate cryptographic hashes for files
• Template Support – Support for EJS templates with dynamic data
• JSON Data Loading – Load template data from JSON files
• Key Management – Generate and manage RSA key pairs
• Output Management – Flexible output directory and file naming

📦 Packages

@contract-js/core

PDF Contract Generation from EJS Templates

Core functionality for generating PDF contracts from EJS templates with digital signature support.

• PDF Generation – Convert EJS templates to PDF documents
• Template Rendering – Render EJS templates with dynamic data
• Watermark Support – Add watermarks to PDF documents

@contract-js/crypto

Digital Signature Generation and Verification

Cryptographic utilities for digital signature generation and verification.

• RSA Key Generation – Generate RSA key pairs for digital signatures
• Digital Signing – Create digital signatures for PDF contracts
• Signature Verification – Verify digital signatures against PDF hashes

@contract-js/pdf-utils

PDF Hash Generation and Comparison

Utility functions for PDF hash generation and comparison.

• PDF Hashing – Generate cryptographic hashes for PDF documents
• Hash Comparison – Compare PDF hashes to detect changes
• Buffer Conversion – Convert PDF hashes to buffers for cryptographic operations

🚀 Quick Start

CLI Usage

# Install CLI globally
npm install -g @contract-js/cli

# Generate PDF contract from EJS template
contract-js generate template.ejs -d data.json -o contract.pdf

# Generate file hash
contract-js hash contract.pdf

# Sign contract with digital signature
contract-js sign contract.pdf -o ./keys

# Verify digital signature
contract-js verify contract.pdf -p ./keys/public.pem -s ./keys/signature.txt

# Show help
contract-js --help

# Show version
contract-js --version

CLI Commands

Command	Description	Options
generate <template>	Generate PDF from EJS template	-d, --data <path> - JSON data file path -o, --output <path> - Output PDF file path
hash <filePath>	Generate file hash	-a, --algorithm <algo> - Hash algorithm (default: sha256)
sign <filePath>	Sign PDF with digital signature	-a, --algorithm <algo> - Hash algorithm -o, --output <dir> - Keys output directory -k, --key <path> - Private key file path
verify <filePath>	Verify digital signature	-a, --algorithm <algo> - Hash algorithm -p, --public-key <path> - Public key file path -s, --signature <path> - Signature file path

Programmatic Usage

import { generatePdf } from '@contract-js/core';
import { signContract, verifyContractSignature } from '@contract-js/crypto';

// Generate PDF
const result = await generatePdf({
  templatePath: './template.ejs',
  templateData: { title: 'Service Agreement' }
});

// Sign PDF
const signature = await signContract({
  pdfHash: result.pdfHash,
  privateKey: privateKeyPem,
  algorithm: 'sha256'
});

// Verify signature
const isValid = verifyContractSignature({
  algorithm: 'sha256',
  pdfHash: result.pdfHash,
  publicKey: publicKeyPem,
  signature: signature.signature
});

📦 Installation

# Install CLI package
npm install @contract-js/cli

# Install all packages
npm install @contract-js/core @contract-js/crypto @contract-js/pdf-utils

# Or install individually
npm install @contract-js/core
npm install @contract-js/crypto
npm install @contract-js/pdf-utils

⚙️ Tech Stack

Tool	Purpose
pnpm + Turbo	Monorepo workspace management
tsup	Bundling ESM/CJS with type declarations
TypeScript	Language with strict settings
ESLint + Prettier	Code linting and formatting
Puppeteer	HTML to PDF conversion
pdf-lib	PDF manipulation
EJS	Template engine
CAC	CLI framework for command parsing
@clack/prompts	Interactive CLI prompts and UI

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📝 License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Copyright © Jeonhui