GroupDocs.Signature is an on-premise e-signature API that adds text, image, digital (certificate), barcode, QR code, stamp, form-field and metadata signatures to PDF, Word, Excel, PowerPoint, OpenDocument and image files, and searches, verifies, updates and removes the signatures a document already carries. SDKs for .NET, Java, Node.js and Python.

• NEW: GroupDocs.Signature for Python via .NET 26.10 on PyPI: engine 26.9 with the .NET 10 runtime embedded, Python 3.5 - 3.14 on Windows, Linux and macOS (Intel and Apple Silicon), and Python callbacks for previews, loggers, encryption and external signing. Release notes.
• Published GroupDocs.Signature 26.9 for .NET on NuGet: expired and not-yet-valid certificates are rejected by default, external resources are not loaded, and PDF signatures use SHA-256 and are verified cryptographically.
• Released GroupDocs.Signature.Mcp 26.9: an MCP server that lets AI agents sign and verify documents locally. Get started.

Sign, verify, search, update and remove signatures in PDF, Office, OpenDocument and image files on .NET Framework 4.6.2+ and .NET 6, 8 and 10.

• GroupDocs.Signature-for-.NET: Core API examples for every signature type.
• MVC Demo and Web Forms Demo: e-signature UI samples.

using GroupDocs.Signature;
using GroupDocs.Signature.Domain;
using GroupDocs.Signature.Options;

using (var signature = new Signature("document.pdf"))
{
    var options = new ImageSignOptions("signature.png")
    {
        Left = 100,
        Top = 100,
        Width = 200,
        Height = 80
    };
    SignResult result = signature.Sign("signed.pdf", options);
    Console.WriteLine($"Signed with {result.Succeeded.Count} signature(s)");
}

Native Java library to apply and verify digital, barcode, QR code, image, text, stamp and metadata signatures.

• GroupDocs.Signature-for-Java: Java examples; the package com.groupdocs:groupdocs-signature comes from the GroupDocs Maven repository.

import com.groupdocs.signature.Signature;
import com.groupdocs.signature.domain.SignResult;
import com.groupdocs.signature.options.sign.ImageSignOptions;

// Sign a PDF with an image signature
Signature signature = new Signature("document.pdf");
ImageSignOptions options = new ImageSignOptions("signature.png");
options.setLeft(100);
options.setTop(100);
options.setWidth(200);
options.setHeight(80);

SignResult result = signature.sign("signed.pdf", options);
System.out.println("Signed with " + result.getSucceeded().size() + " signature(s)");
signature.dispose();

Add e-signature flows to Node.js services and scripts with the Java engine.

• GroupDocs.Signature-for-Node.js-via-Java: Node.js examples; install with npm install @groupdocs/groupdocs.signature.

const groupdocs = require('@groupdocs/groupdocs.signature');

// Sign a PDF with an image signature
const signature = new groupdocs.Signature('document.pdf');
const options = new groupdocs.ImageSignOptions('signature.png');
options.setLeft(100);
options.setTop(100);
options.setWidth(200);
options.setHeight(80);

const result = signature.sign('signed.pdf', options);
console.log(`Signed with ${result.getSucceeded().size()} signature(s)`);
signature.dispose();

A self-contained Python package with the .NET runtime embedded: pip install groupdocs-signature-net, Python 3.5 - 3.14.

• GroupDocs.Signature-for-Python-via-.NET: Runnable examples for every signature type and operation, with a Dockerfile.
• PyPI | Docs | API Reference | Release Notes

from groupdocs.signature import Signature
from groupdocs.signature.options import ImageSignOptions

with Signature("document.pdf") as signature:
    options = ImageSignOptions("signature.png")
    options.left = 100
    options.top = 100
    options.width = 200
    options.height = 80
    result = signature.sign("signed.pdf", options)
    print("Signed with %d signature(s)" % len(result.succeeded))

Let AI agents sign and verify documents through the GroupDocs engine, locally over MCP: no uploads, works in evaluation mode out of the box and with your existing license.

• GroupDocs.Signature.Mcp: The MCP server: sign with text, QR code, barcode or digital signatures, verify signatures, read QR codes and barcodes.
• GroupDocs.Mcp.Installer: Cross-platform installer with per-client registration (Claude Desktop, Claude Code, VS Code, Cursor and more).
• GroupDocs.Signature.Mcp.Tests: Integration suite that verifies every published release.

# Install and run in one command (.NET 10), then ask your agent:
dnx GroupDocs.Signature.Mcp --yes

"Sign contract.pdf with a QR code containing our order reference." "For every PDF in my documents folder, check whether it is digitally signed and still valid."

MCP documentation | NuGet | Docker | MCP Registry

• E-sign PDFs, Word, Excel, PowerPoint and images with digital certificates.
• Customer onboarding and approvals with image and text signatures in web or desktop apps.
• Compliance and audit trails: search for signatures and verify them.
• Batch signing, search and removal of barcodes and QR codes for logistics and labeling.
• Metadata signatures to track document versions and ownership.

• 40+ formats: PDF, Word (DOC, DOCX, ODT and templates), Excel (XLS, XLSX, ODS and templates), PowerPoint (PPT, PPTX, ODP), and images (PNG, JPG, TIFF, BMP, GIF, SVG, WEBP, PSD and more).
• Signature types: digital (X.509 certificates), image, text, barcode, QR code, stamp, metadata, form-field.
• Search, verify, update and remove existing signatures.
• Positioning and appearance: fonts, colors, alignment, margins, borders, backgrounds and transparency.
• Document and signature previews; password-protected documents.

• .NET: dotnet add package GroupDocs.Signature
• Java: add com.groupdocs:groupdocs-signature from the GroupDocs repository, https://releases.groupdocs.com/java/repo/
• Node.js: npm install @groupdocs/groupdocs.signature
• Python: pip install groupdocs-signature-net
• Run the sample projects from the repositories above to sign, verify, search and remove signatures.

• Documentation and tutorials: https://docs.groupdocs.com/signature/
• Free support forum: https://forum.groupdocs.com/c/signature
• Temporary license for full-feature evaluation: https://purchase.groupdocs.com/temporary-license

mcp mcp-server ai-agents python groupdocs-signature digital-signature esignature-api sign-pdf sign-word sign-excel sign-images verify-signature remove-signature barcode-signature qr-code-signature metadata-signature form-field-signature esign-pdf esign-document signature-sdk electronic-signature pdf-esign sign-docx sign-xlsx signature-validation signature-verification audit-trail