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The build command runs the full Refractor pipeline: compiles your Dart source to kernel bytecode, applies obfuscation passes defined in refractor.yaml, and outputs the result in your chosen format.

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Usage

refractor build [options]

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Options

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--input
string
default:"lib/main.dart"
Input Dart file or directory to compile. Specify the entrypoint of your application.Short flag: -i
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--output
string
default:"build"
Output directory path. The final artifact will be written as build/out.<extension> where the extension depends on the target type.Short flag: -o
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--target
string
default:"exe"
Target format to build for. Determines the output file type and compilation strategy.Short flag: -tAllowed values:
  • exe - Standalone executable (no extension)
  • aot - AOT snapshot (.aot extension)
  • jit - JIT snapshot (.jit extension)
  • kernel - Kernel bytecode only (.dill extension)

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Build Pipeline

The build command executes these steps:
1

Load Configuration

Reads refractor.yaml from the current directory. The build will fail if this file is missing or malformed.
2

Compile to Kernel

Compiles the input Dart file to kernel bytecode (.dill format) using dart compile kernel.
3

Apply Obfuscation Passes

Processes the kernel bytecode with each enabled pass:
  • Rename - Rewrites identifiers to short meaningless names
  • String Encryption - XOR-encodes string literals with runtime decoder
  • Dead Code Injection - Inserts unreachable branches
4

Compile to Target

Compiles the obfuscated kernel to the specified target format using dart compile <target>.
5

Write Symbol Map

Generates a JSON file mapping obfuscated names back to their originals. The output path is configured via refractor.symbol_map in your config file.

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Examples

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Build Executable (Default)

Compile to a standalone executable: 
refractor build
Outputs: build/out (executable file)

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Build Kernel Only

Compile to obfuscated kernel bytecode without final compilation: 
refractor build --target kernel
Outputs: build/out.dill
Use the kernel target when you want to inspect the obfuscated bytecode with refractor inspect or integrate with custom build pipelines.

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Build AOT Snapshot

Generate an ahead-of-time compiled snapshot: 
refractor build --target aot --output dist
Outputs: dist/out.aot

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Custom Input File

Build from a different entrypoint: 
refractor build --input bin/server.dart --output build/server
Outputs: build/server/out

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Build JIT Snapshot

Create a just-in-time compiled snapshot: 
refractor build --target jit
Outputs: build/out.jit

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Output

On success, the command prints: 
✓ Build complete: build/out.exe
The build process also:
  • Creates the output directory if it doesn’t exist
  • Writes the symbol map to the path specified in refractor.yaml
  • Returns exit code 0 on success
The build command requires a valid refractor.yaml configuration file in the current directory. Run refractor init first if you don’t have one.

refractor init

Generate a starter configuration file

refractor inspect

Inspect the contents of a .dill file

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