prek/docs/diff.md

Differences from pre-commit

General differences

• prek supports .pre-commit-config.yaml, .pre-commit-config.yml, and native prek.toml configuration files. Use prek util yaml-to-toml to convert an existing YAML config.
• prek implements some common hooks from pre-commit-hooks in Rust for better performance.
• prek supports repo: builtin for offline, zero-setup hooks.
• prek uses ~/.cache/prek as the default cache directory for repos, environments and toolchains.
• prek decouples hook environments from their repositories, allowing shared toolchains and environments across hooks.
• prek supports language_version as a semver specifier and automatically installs the required toolchains.
• prek supports files and exclude as glob lists (in addition to regex) via glob mappings. See Configuration.
• prek reports more precise configuration parsing errors, including exact source locations.

Workspace mode

prek supports workspace mode, allowing you to run hooks for multiple projects in a single command. Each subproject can keep its own prek.toml or .pre-commit-config.yaml file.

See Workspace Mode for more information.

Language support

See the dedicated Language Support page for a complete list of supported languages, prek-specific behavior, and unsupported languages.

Recent releases added support for more managed hook runtimes, including Bun, Julia, Deno, and experimental .NET support.

Command line interface

For a compatibility-focused command mapping, see Compatibility with pre-commit.

prek run

• prek run [HOOK|PROJECT]... supports selecting or skipping multiple projects or hooks in workspace mode, instead of only accepting a single optional hook id. See Running Specific Hooks or Projects for details.
• prek run can execute hooks in parallel by priority (hooks with the same priority may run concurrently), instead of strictly serial execution.
• prek provides dynamic completion for hook ids.
• prek run --dry-run shows which hooks would run without executing them.
• prek run --last-commit runs hooks on files changed by the last commit.
• prek run --directory <DIR> runs hooks on a specified directory.
• prek run --no-fail-fast lets you override the configured fail_fast setting for a single run and continue after failures.

prek install

• prek install and prek uninstall honor repo-local and worktree-local core.hooksPath when choosing where to manage Git shims.

prek validate-config

• prek validate-config accepts both prek.toml and .pre-commit-config.yaml.

prek list

prek list lists all available hooks, their ids, and descriptions. This provides a better overview of the configured hooks.

prek auto-update

• prek auto-update updates all projects in the workspace to their latest revisions.
• prek auto-update checks updates for the same repository only once, speeding up the process in workspace mode.
• prek auto-update supports --dry-run to preview the updates without applying them.
• prek auto-update supports --check to exit non-zero when updates are available or frozen-reference mismatches are found, without rewriting the config.
• prek auto-update validates pinned SHA revisions against fetched upstream refs, including impostor-commit detection, and keeps stale # frozen: comments in sync when it can.
• prek auto-update supports the --cooldown-days option to skip releases newer than the specified number of days (based on the tag creation timestamp for annotated tags, or the tagged commit timestamp for lightweight tags).
• prek auto-update supports --exclude-repo to skip selected repositories while updating everything else.
• prek auto-update supports tag filtering with --include-tag, --exclude-tag, --repo-include-tag, and --repo-exclude-tag, using glob patterns to keep or remove matching tags before selecting an update.

prek sample-config

• prek sample-config can generate either YAML or TOML and can write directly to a file with --file.

prek util

• prek util identify shows the file-identification tags prek uses for filtering and debugging hook selection.
• prek util list-builtins lists all built-in hooks bundled with prek.
• prek util yaml-to-toml converts .pre-commit-config.yaml to prek.toml.

prek cache

• prek groups cache maintenance under prek cache instead of separate top-level clean and gc commands.
• prek cache gc removes unused cached repositories, environments and toolchains, and supports --dry-run.
• prek cache clean removes all cached data.
• prek cache dir and prek cache size help inspect the cache before or after cleanup.

Not implemented

The pre-commit hazmat subcommand introduced in pre-commit v4.5.0 is not implemented. This command is niche and unlikely to be widely used.