Getting Started

How to install the Trunk CLI to check your code in less than 60 seconds.

The trunk command line tool runs locally on your developer machine, right where your code is. Later, you can automatically scan your repo using the Trunk Check webapp. Trunk Check will automatically keep tools up to date, suggest standard tools for your project type (eg: clang-format for C++, eslint for JS/TS), and pin versions in trunk.yaml to ensure Trunk Check is reproducible.

Install the CLI

Run one of the following to install the trunk command line tool.

curl -fsSL | bash

Initialize trunk

From the root of a git repo, run:

trunk init

This will scan your repository and create a .trunk/trunk.yaml that enables all the linters, formatters, and security analyzers that are recommended for your project based on the source code types (*.c, *.py, *.js, etc.) as well as existing tool configuration files (ex: .eslintrc, .clang-format, .flake8). You can enable additional linters with the trunk check enable <toolname> command. For more details, see here.

Basic Usage

The main commands when running trunk from the command line are:

trunk check       # runs the universal linter on all applicable files
trunk fmt         # runs all the enabled formatters and auto-applies changes

You can always find this list using trunk check --help.

Trunk is git-aware. When you run trunk check it will only run on files you've modified according to git. To run on a sampling in your repo, run: trunk check --sample 5


trunk check runs linters & formatters on your changed files, prompting you to apply fixes. Without additional args, trunk check will run all applicable linters on all files changed in the current branch.


Run all applicable formatters as configured in trunk.yaml. trunk fmt is short-hand for running trunk check with a --fix --filter set to all formatters enabled in your repository.




Run on all the files in the repository. Useful if trying to assess a new linter in the system, or to find and fix pre-existing issues


Auto-apply all suggested fixes


Surface, but do not prompt for autofixes


List of comma-separated linters to run. Specify --filter=-linter to disable a linter.


Run check on a sampling of all files in the repo


Output help information



all files

trunk check --all --no-fix

a specific file

trunk check some/

all applicable files with flake8

trunk check --all --no-fix --filter=flake8

a selection of five files in the repo

trunk check --sample 5

a selection of five files in the repo with a specific linter

trunk check --sample 5 --filter=flake8

format the whole repo

trunk fmt --all

format a specific file

trunk fmt some/

format all python code with black

trunk fmt --all --filter=black

Manage the linters

List all of the available linters

trunk check list

Enable a single linter

trunk check enable <linter name>

Disable a single linter

trunk check disable <linter name>

CI Setup

Once you have Trunk Check configured on your local machine, you can set up the Trunk Check webapp to automatically run checks whenever your CI system builds and runs tests. See Continuous Integration Setup for more information.

Hold the Line

By default Trunk Check will Hold The Line, meaning it will only run against new changes in your codebase, not old ones. For more see Hold the Line.

Ignoring Issues by Line

To tell Trunk Check to ignore a line in your source code with a special comment like this:

struct FooBar {
  // trunk-ignore(clang-tidy)
  void *ptr = NULL;

The comment should contain the name of the linter you want to ignore the following line, in this case clang-tidy For more complex ignore commands, see Ignoring Issues.

Ignoring Issues by File

Sometimes you may want to ignore entire files or groups of files, such as generated code. To ignore them, use the ignore key to your .trunk/trunk.yaml file:

    - linters: [ALL]
        # Ignore generated files
        - src/generated/**

See Ignoring Multiple Files more information.


trunk upgrade will upgrade the Trunk CLI, along with all plugins and linters in your trunk.yaml. We highly recommend running on the latest validated versions of tools as updates will frequently include important security fixes and additional valuable checks. Trunk only auto-suggests linter upgrades to versions that we have tested and support, so you may see a slight lag time when a new linter version is released.

trunk upgrade

trunk upgrade will also recommend new tools that have become applicable since the last time your repository was scanned. This can be a result of using new technologies in your repository or trunk itself adding support for more tools. If you don't like a particular recommendation you can run trunk check disable <linter> to teach trunk not to recommend it.

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