pyobfus

Modern Python Code Obfuscator

An open-source PyArmor alternative for teams that need to obfuscate before shipping without giving up production debugging. pyobfus emits portable Python through AST transformations and can reverse-map protected stack traces back to original identifiers for developers and AI coding assistants. Supports Python 3.9 through 3.14.

Features

🆓 Community Edition (Free)

• Name Obfuscation: Rename variables, functions, and classes to I0, I1, I2...
• Comment Removal: Strip comments and docstrings
• String Encoding: Base64 encoding for string literals
• Numeric / Constant Obfuscation (--numeric-obfuscation): replace integer/float literals with value-preserving opaque expressions
• AI Provenance Stripping (--strip-ai-artifacts): remove Generated by Claude / Co-Authored-By markers from docstrings and attribution dunders
• Incremental Builds (--incremental): skip a directory rebuild when inputs and config are unchanged
• Multi-file Support: Obfuscate entire projects
• Reverse Stack-Trace Mapping (--unmap): translate an obfuscated production traceback back to original names, so you (or an AI assistant) can debug shipped code without un-obfuscating it
• Pre-flight Risk Check (--check): flags eval/exec, dynamic attribute access, framework reflection, declared dependencies that do not resolve on public PyPI, and (for hardened Python 3.14+ deployments) PEP 768 remote-debug exposure — config-aware, JSON output, and --sarif export for GitHub Code Scanning
• YAML Configuration: Flexible configuration system
• Parameter Preservation: Keep function parameter names for keyword arguments
• Build Provenance: Local provenance manifest with hashes and CycloneDX-compatible relationships; --verify-provenance-manifest validates it
• Structured Dry-Run Plan & Syntax Verification (v0.5.19): --dry-run --json previews a versioned plan; --verify-syntax compiles generated output in memory after a build (no import, no execution)

💎 Professional Edition - $45 USD

• ✨ All Community Features +
• 🔀 Control Flow Flattening: Transform code structure into state machines
• 🧩 Dead Code Injection: Inject unreachable code to increase complexity
• 🔐 AES-256 String Encryption: Military-grade encryption for strings
• 🛡️ Anti-Debugging Checks: Detect and prevent debugging attempts
• 📅 License Embedding: Expiration dates, machine binding, run limits
• 🧱 v0.5 build-fusion mechanisms (compose via pyobfus SRC -o OUT --level pro --<flag>): Selective Opacity, Seal-Code, String Vault, Scrub-Traceback, Fingerprint, Expire-Hard — plus run-counter cap, targeted opacity config, device-locked keys, and runtime import obfuscation
• ⚡ Configuration Presets: One-command setup (trial, commercial, library)
• 🔄 Lifetime Updates: All future Pro features included
• 💻 Up to 3 Devices: Use on multiple machines
• 📧 Priority Email Support

Buy Now - $45 USD →

📄 More purchase details ↓

Installation

From PyPI (recommended):

pip install pyobfus

From source (for development):

git clone https://github.com/zhurong2020/pyobfus.git
cd pyobfus
pip install -e .

Quick Start

Obfuscate a single file:

pyobfus input.py -o output.py

Obfuscate a directory:

pyobfus src/ -o obfuscated/

With configuration:

pyobfus src/ -o obfuscated/ --config pyobfus.yaml

With an offline provenance manifest:

pyobfus src/ -o obfuscated/ --save-mapping mapping.json --provenance-manifest provenance.json
pyobfus --verify-provenance-manifest provenance.json --json

Example

Before obfuscation:

def calculate_total(price, quantity):
    """Calculate total price."""
    tax_rate = 0.1
    subtotal = price * quantity
    tax = subtotal * tax_rate
    return subtotal + tax

After obfuscation:

def I0(I1, I2):
    I3 = 0.1
    I4 = I1 * I2
    I5 = I4 * I3
    return I4 + I5

Note: Variable names may vary slightly, but functionality is preserved.

Documentation

• README - Full documentation
• Provenance Manifest - Obfuscated-output manifest fields and integrity notes
• Release Provenance - PyPI Integrity API and attestation verification runbook
• Current Plan - Current project status and priorities
• Changelog - Version history
• Security Policy - Report vulnerabilities

Community & Support

• GitHub Issues - Bug reports and feature requests
• GitHub Discussions - Questions and ideas
• Contributing - How to contribute

Purchase Professional Edition

💎 Professional Edition - $45 USD

One-time payment • Lifetime access

💳 Pay by card, Apple Pay, or WeChat Pay (微信支付) for buyers in China — Stripe shows the methods available for your region at checkout. Alipay (支付宝) is being enabled.

What's Included:

• ✅ Control Flow Flattening - State machine transformation
• ✅ Dead Code Injection - Increase code complexity
• ✅ AES-256 String Encryption
• ✅ Anti-Debugging Checks
• ✅ License Embedding - Expiration, machine binding, run limits
• ✅ Configuration Presets - One-command setup
• ✅ Lifetime Updates
• ✅ Up to 3 Devices
• ✅ Email Support (zhurong0525@gmail.com)

🚀 Buy Now - $45 USD

⚡ Instant delivery • 🔒 Secure checkout • 💯 30-day money-back guarantee

Try Before You Buy

Want to test Pro features before purchasing? Use the 5-day free trial:

# Start a free trial (no registration, no credit card required)
pyobfus-trial start

# Quick start with presets
pyobfus src/ -o dist/ --preset commercial

# Or use individual features
pyobfus input.py -o output.py --control-flow --string-encryption --anti-debug --dead-code

# With license restrictions
pyobfus src/ -o dist/ --expire 2027-12-31 --bind-machine

# Check trial status
pyobfus-trial status

The trial includes all Pro features with full functionality for 5 days.

!!! note “The trial is an honor-system control” Trial state lives in an unsigned file in your home directory, and pyobfus/trial.py ships as readable Apache-2.0 source, so the trial is a convenience control rather than a security boundary. We document it that way instead of claiming enforcement it cannot deliver — see the security policy. The Community Edition has no file or line limits and requires no trial.

How to Purchase

Step 1: Click “Buy Now” and complete secure checkout (Stripe)

Step 2: Receive your license key via email within minutes

Step 3: Activate your license

pip install --upgrade pyobfus
pyobfus-license register PYOB-XXXX-XXXX-XXXX-XXXX

Activation Guide

Full activation instructions: License Activation Guide

Legal & Policies

By purchasing pyobfus Professional Edition, you agree to our:

• Terms of Service & EULA
• Refund Policy - 30-day money-back guarantee
• Privacy Policy - GDPR compliant

---

Security Note

String Encryption Limitations: AES-256 string encryption is designed as a deterrent against casual reverse engineering, not as cryptographic security. Because obfuscated code must decrypt strings at runtime, the encryption key is embedded in the output. This is a fundamental limitation of all client-side obfuscators.

Recommendation: For sensitive credentials (API keys, passwords), use environment variables or external secret management systems rather than embedding them in code.

See our full README for detailed security guidance.

---

License

Dual License Model:

• pyobfus (Core): Apache 2.0 - Free and open source
• pyobfus_pro (Pro): Proprietary - Requires paid license

---

Built with Python 3.9-3.14 • AST-based Transformations • Open Source