How to Programmatically Sign PDF Documents with Digital Signatures

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Accelerate your document workflows and ensure cryptographic security by learning how to programmatically sign PDFs with digital signatures using the pdfRest Sign PDF API Tool. This REST API Pro Tool is designed to apply secure digital signatures to PDF documents using your own PFX or certificate credentials. If you're looking for a reliable, automated solution to programmatically sign PDFs at scale while ensuring document integrity and brand consistency, pdfRest offers powerful features to meet your needs.

Why Programmatically Sign PDFs?

Accelerate Document Processing: Programmatically apply signatures to high-volume documents, significantly speeding up contract execution, legal agreements, and HR document processing.
Enhance Document Integrity and Authenticity: Embed cryptographically secure signatures that bind a signer's identity to a document, ensuring it hasn't been altered.
Ensure Industry Compliance: Meet strict industry and regulatory requirements (e.g., HIPAA, SOX, GDPR) by applying verifiable digital signatures that are compliant with global standards.
Streamline Workflows: Seamlessly integrate automated signing capabilities into your existing applications, such as CRM, ERP, or document management systems.
Reinforce Brand Identity: Add consistent, professional visual signatures using logos or typed text to maintain brand identity and a professional appearance across all documents.

Why Choose pdfRest API for Programmatic PDF Signing?

Comprehensive Credential Support: Our API offers unparalleled flexibility by supporting a wide range of credential formats, including **PFX / PKCS#12 (.pfx, .p12)**, **PEM (.pem)**, and **DER (.der)** files, ensuring compatibility with your existing security infrastructure.
Customizable Electronic Signature Appearances: While applying a secure digital signature, the API allows you to customize its visual appearance. You can display a typed name, a logo, or a scanned handwritten signature and control elements like opacity, date/time, contact information, location, and reason for signing.
Optimized for High-Volume & Compliance-Driven Workflows: The pdfRest Sign PDF API is purpose-built to handle scenarios where secure, verifiable document execution at scale is essential. It empowers you to handle automated contract execution, large-scale legal filings, and other demanding business processes.
Developer-Friendly API: Simple integration with clear documentation, detailed parameter schemas, and readily available code samples for various programming languages.
Scalable and Reliable: Built for consistent performance, handling diverse file formats and high processing volumes without compromising security.
Secure Processing: Ensures the privacy and security of your documents and credentials throughout the signing process.

How to Programmatically Sign PDFs with pdfRest

Here's a simple example of how to use cURL to send a request to the pdfRest API to programmatically apply a digital signature to a PDF using PFX credentials and a custom visual appearance:

curl -X POST "https://api.pdfrest.com/signed-pdf" \
  -H "Accept: application/json" \
  -H "Content-Type: multipart/form-data" \
  -H "Api-Key: YOUR_API_KEY" \
  -F "file=@/path/to/your_document.pdf" \
  -F "pfx_credential_file=@/path/to/your_credential.pfx" \
  -F "pfx_passphrase_file=@/path/to/your_passphrase.txt" \
  -F "signature_configuration={\"type\":\"new\",\"name\":\"my-signature-field\",\"location\":{\"bottom_left\":{\"x\":50,\"y\":50},\"top_right\":{\"x\":250,\"y\":150},\"page\":1},\"display\":{\"name\":\"John Doe\",\"reason\":\"I approve this document\"}}" \
  -F "output=signed_document"

Replace YOUR_API_KEY with your actual pdfRest API key and adjust the file paths for your document, PFX file, and passphrase file. The signature_configuration parameter is a required JSON string that defines the signature's properties and appearance.

Get Started Fast with Tutorials for Common Programming Languages

To help you integrate programmatically sign PDFs functionality into your specific development environment, we offer the following tutorials:

Try Now in API Lab

Experience how easy it is to programmatically sign PDFs directly in your browser using our API Lab. Upload your PDF, configure your signature, generate the code, send the API call, and download the cryptographically signed PDF to validate its authenticity.

Start Programmatically Applying Digital Signatures Today!

Secure your documents, accelerate your workflows, and ensure compliance by integrating the pdfRest API to programmatically sign PDFs. For detailed information on implementation and all available parameters, refer to our comprehensive API Documentation. Sign up for a free pdfRest account (Pro features are available with Pro/Enterprise plans or per-call for Premium users) and start automating your digital signing tasks today!