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Configuration

You can configure CI Fuzz to fit your project's needs. The easiest and most common way is by using a cifuzz.yaml file in your project's root directory.

Project Configuration​

For project-specific settings that you want to share with your team, the cifuzz.yaml file is the recommended approach. When you run cifuzz init, an empty cifuzz.yaml file is created.

Here is an example of a cifuzz.yaml file:

cifuzz.yaml
# The build system used by your project (e.g., cmake, bazel, other).
build-system: cmake

# Directory where the compilation database (compile_commands.json) is located.
build-dir: "build"

# Engine used for fuzzing
engine: "libfuzzer"

# Settings for the AI Test Agent (Spark)
num-candidates: 10
target-coverage: 80

Discovering Configuration Options​

The best way to see all available configuration options is to use the --help flag with any CI Fuzz command. This ensures you always see the most up-to-date list of options.

For example, to see all options for the run command:

cifuzz run --help

To see options for other commands, you can use:

  • cifuzz --help (Global options)
  • cifuzz create --help
  • cifuzz spark --help

Alternative Configuration Methods​

While cifuzz.yaml is best for most projects, you can also use environment variables or a global configuration file for specific use cases.

Environment Variables​

You can override any setting using environment variables by prefixing the option name with CIFUZZ_. This is useful for temporary settings or for use in CI/CD pipelines.

Example:

# Override the target coverage and number of candidates for a single run
export CIFUZZ_TARGET_COVERAGE=80
export CIFUZZ_NUM_CANDIDATES=5

cifuzz spark

Global Configuration​

To set personal default options that apply to all your projects, you can create a global config.yaml file.

File Location:

  • Linux: $HOME/.config/cifuzz/config.yaml (or $XDG_CONFIG_HOME/cifuzz/config.yaml)
  • macOS: $HOME/Library/Application Support/cifuzz/config.yaml

Example:

~/.config/cifuzz/config.yaml
# My personal default engine for all projects
engine: "libfuzzer"

Configuration Precedence​

CI Fuzz applies configurations in the following order (highest precedence first):

  1. Environment Variables (e.g., CIFUZZ_ENGINE)
  2. Project Configuration (cifuzz.yaml)
  3. Global Configuration (config.yaml)

This means an environment variable will always override a setting in your project's cifuzz.yaml.