pyobfus — the Python obfuscator

pyobfus (pronounced as "Python obfuscator") is a modern, AST-based python-obfuscator / code-obfuscator with framework-aware presets, reverse stack-trace mapping for AI-assisted debugging, and a machine-readable JSON CLI designed for Claude Code, Cursor, Codex, and MCP agents. A transparent, open-source alternative to PyArmor.

A Python code obfuscator built with AST-based transformations. Supports Python 3.9 through 3.14. Provides reliable name mangling, string encoding, control-flow flattening, AES-256 string encryption, and — unique to pyobfus — a reverse-mapping workflow that lets you (or your AI coding assistant) debug obfuscated stack traces without giving up the protection.

🔒 Pro Edition available — 6 patent-targeted protection mechanisms (Selective Opacity, forensic watermarking, Runtime String Vault, and more) layered on top of the free AST obfuscator, $45 one-time, no subscription. See Pro Edition below.

🔧 What's new in v0.5.11 — --anti-debug now checks three more signals beyond the original sys.gettrace(): TracerPid (Linux native debuggers), WinAPI IsDebuggerPresent() (Windows), and a timing-skew check that catches single-stepping on any platform. v0.5.10 added --embed-data <path> (AES-256-GCM resource-file embedding) and, separately, pyobfus-mcp 0.3.4 added PII-shape detection to its risk scan. v0.5.9 added --requires-os / --requires-python-min / --requires-arch platform restrictions. Full details in the CHANGELOG; see Pro Edition below.

🔌 Companion MCP server: pyobfus-mcp

This repository ships two installable packages:

Package	What it is	Install
pyobfus	The Python obfuscator (CLI + library).	pip install pyobfus
pyobfus-mcp	A Model Context Protocol (MCP) server that exposes pyobfus's tools to AI coding agents.	uvx pyobfus-mcp (zero-install) or pip install pyobfus-mcp

The MCP server lives in pyobfus_mcp/ and is built on the official Model Context Protocol Python SDK (FastMCP). It registers eight MCP tools so Claude Desktop, Claude Code, Cursor, Windsurf, Zed, and Codex can call pyobfus directly from agent conversations — no shelling out: