README.md

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Prometheus is a Lua obfuscator written in pure Lua.

It applies a range of AST-based transformations to make source code significantly harder to read, analyze, and reverse engineer.
These include register VM virtualization, control-flow flattening, constant encryption, and other Lua-specific obfuscation strategies.

The project was inspired by the excellent javascript-obfuscator.

Currently, Prometheus supports:

• Lua 5.1
• LuaU (basic support is available, but still not fully finished)

Lua 5.1's legacy implicit arg table in vararg functions is unsupported. Use ... and select('#', ...) instead; see Limitations. Replacing a function's environment while it is running is also unsupported; set the environment before calling the function.

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Quick Start

Try the browser version first:

Install CLI (Linux/macOS)

Install latest release with one command:

curl -fsSL https://raw.githubusercontent.com/prometheus-lua/Prometheus/master/install.sh | sh

Then use the CLI directly:

prometheus-lua --version
prometheus-lua --preset Medium ./your_file.lua

The release bundle includes a Lua runtime, so no separate Lua install is required for the packaged CLI.

To update to the latest release:

prometheus-lua update

To uninstall:

rm -f ~/.local/bin/prometheus-lua && rm -rf ~/.local/share/prometheus-lua

Local source usage

git clone https://github.com/prometheus-lua/Prometheus.git
cd Prometheus
lua cli.lua --preset Medium ./your_file.lua

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Documentation

You can find the full documentation, including the getting started guide, here:

Contribution guidelines: CONTRIBUTING.md

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Requirements

Packaged CLI releases include a bundled Lua runtime. For source usage, Prometheus requires LuaJIT or Lua 5.1+.

Lua 5.1 binaries can be downloaded here:
https://sourceforge.net/projects/luabinaries/files/5.1.5/Tools%20Executables/

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Example

Input

-- input.lua
print("Hello, World!");

Obfuscated output

-- input.obfuscated.lua
return(function(...)local L={"afT6mf1V","/7mJXsuvmE1c/fT3";"tn1ZSn6=","37ghSJM=";"WqermfWAWuuZpb3XX7M=","tqXGSJ3u","XQXpL9x21dxAWJa//p==","SrM=";"3q+5SJM=","/D==";"t7XUt0p=";"mIeOmIx9";"LdgrBfWdWuNABsb+KJxj","SJWJ4dahKsebW7t+KQv=","/cDu3AvP/D==";"Llv7uD==","tJWhFfTE";"TQ43ctIuy9HIop==","mEu93p==";"WJax1sXEXEaxWuxGt6==","t0gPSEp=",...
-- remaining obfuscated output omitted

For more advanced use cases, configuration, and presets, see the documentation.

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Tests

The test suite runs existing cases on Lua 5.1 and Luau, plus the adapted official Lua 5.1 suite on Lua 5.1, inside Docker:

./scripts/run-tests.sh           # Run all tests (default: 10 iterations)
./scripts/run-tests.sh -b        # Build image and run tests
./scripts/run-tests.sh -n 5      # Run with 5 iterations
./scripts/run-tests.sh -c config.lua  # Use a custom config
./scripts/run-tests.sh -v        # Verbose output
./scripts/run-tests.sh --suite upstream --baseline-only  # Verify official originals
./scripts/run-tests.sh --case lua51/closure.lua --preset Cff --seed 4 -n 1

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Community

Prometheus has an official Discord server:

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License and Commercial Use

Prometheus is licensed under the Prometheus License, a modified MIT-style license.

You are free to use, modify, and distribute this software, including for commercial purposes, under the following conditions:

• Any commercial product, wrapper, or service (including SaaS or hosted solutions) that uses or integrates Prometheus must include clear attribution to:

Based on Prometheus by Elias Oelschner, https://github.com/prometheus-lua/Prometheus

• The attribution must be visible in the product’s:
  • UI
  • documentation
  • public website
• The obfuscated output files generated by Prometheus do not need to include any license or copyright notice.
• Derivative works and public forks must also include a statement in their README noting that they are based on Prometheus.

Full license text: Prometheus License

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