groupdocs-signature-net 26.10.0

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Add electronic signatures to documents - text, image, barcode, QR code, digital and stamp signatures.

Key Features

• Text, image, barcode, QR code, stamp, metadata, form-field and digital (certificate) signatures
• Search, verify, update and delete existing signatures
• Document page previews and signature previews, written through your own Python callbacks
• Custom encryption for QR code and metadata signatures, custom loggers, and external signing (HSM, Azure Key Vault) through a Python custom_sign_hash
• PDF, Word, Excel, PowerPoint, OpenDocument and image formats

Installation

pip install groupdocs-signature-net

Quick Start

from groupdocs.signature import Signature
from groupdocs.signature.options import TextSignOptions

with Signature("document.pdf") as sig:
    options = TextSignOptions("Approved")
    sig.sign("signed.pdf", options)

Previews and other callbacks

Wherever the engine takes a callback, pass a Python function or object:

from groupdocs.signature import Signature
from groupdocs.signature.options import PreviewOptions

def create_page_stream(page_data):
    return open("page-%d.png" % page_data.page_number, "wb")

def release_page_stream(page_data, page_stream):
    page_stream.close()

with Signature("document.pdf") as sig:
    sig.generate_preview(PreviewOptions(create_page_stream, release_page_stream))

The same works for signature previews (PreviewSignatureOptions), loggers (SignatureSettings(logger)), data_encryption and custom_sign_hash; AGENTS.md in the package lists the shapes.

Security defaults

The 26.9 engine rejects expired or not-yet-valid signing certificates (DigitalSignOptions.allow_expired / allow_not_yet_valid opt back in), does not load external resources (LoadOptions.skip_external_resources, whitelisted_resources), signs PDFs with SHA-256 and verifies PDF signatures cryptographically.

System Requirements

• Python 3.5 - 3.14, pip 20.3 or newer
• Windows x64, Linux x64, macOS x64/ARM64 — 64-bit Python only; there is no 32-bit Windows wheel
• Linux: glibc 2.27 or newer (e.g. Ubuntu 18.04+, Debian 10+, RHEL 8+), plus ICU, fontconfig, libgdiplus and the Microsoft core fonts: apt-get install libicu-dev libfontconfig1 libgdiplus ttf-mscorefonts-installer (on Debian, enable the contrib component first). libgdiplus is needed for stamp and text-as-image signatures, for barcode, QR code and image signatures with a border or transparency, for any signature on PowerPoint and image files, and for text and stamp signature previews; the core fonts for PDF text and digital signatures, whose default fonts are Times New Roman and Arial.
• macOS 12 or newer, Intel or Apple Silicon: brew install mono-libgdiplus for the same features.

Troubleshooting

Upgrading from 26.1

26.1 was built by an earlier toolchain; the modules are the same, but check these:

• A few names changed: z_order → zorder, x_ad_es_type → xad_es_type, h_corner_radius / v_corner_radius → hcorner_radius / vcorner_radius, FileType.G_ZIP → GZIP, and nine BarcodeTypes constants lost an underscore (GS1_CODE_128 → GS1_CODE128).
• Assigning an attribute a class does not have now raises AttributeError with a suggestion; 26.1 accepted it silently, so a renamed property was simply ignored.
• Engine errors raise GroupDocsSignatureException (or IncorrectPasswordException / PasswordRequiredException) instead of RuntimeError("Proxy error(...)"), and they do not derive from RuntimeError.
• Preview page numbers are 0-based (page_data.page_number is 0 for the first page).
• GROUPDOCS_LIC_PATH is applied at import.

The release notes have the full list.

AI Agent & LLM Friendly

This package is designed for seamless integration with AI agents, LLMs, and automated code generation tools.

• AGENTS.md in the package — AI coding assistants (Claude Code, Cursor, GitHub Copilot) auto-discover the API surface, usage patterns, and troubleshooting tips from the installed package
• MCP server — connect your AI tool to GroupDocs documentation for on-demand API lookups:

  { "mcpServers": { "groupdocs-docs": { "url": "https://docs.groupdocs.com/mcp" } } }
  

• Machine-readable docs — full documentation available as plain text for RAG and LLM context:
  • Single file: https://docs.groupdocs.com/signature/python-net/llms-full.txt
  • Per page: append .md to any docs URL