FerrFlow

Universal semantic versioning for monorepos and classic repos.

Reads your commit history, works out the right version bump, updates your version files,
writes the changelog, and cuts the tagged release. Any language, any repo layout.

Documentation | Changelog | GitHub App

Why FerrFlow?

One compiled binary, no runtime to install. Native monorepo support, 16 version-file formats across every ecosystem below, and it works with whatever layout your repo already has.

ferrflow release

That is the whole release: bump, changelog, tag, GitHub release.

Supported version files

Format	File	Ecosystem	Selector
toml	Cargo.toml	Rust	package.version
toml	pyproject.toml	Python	project.version or tool.poetry.version
json	package.json	Node.js	version
json	composer.json	PHP	version
xml	pom.xml	Java / Maven	first <version> that's a direct child of the root element (skips <parent> and dependencies)
csproj	*.csproj	.NET (C#, F#)	<Version> in <PropertyGroup>
gradle	build.gradle, build.gradle.kts	Java / Kotlin	version = "…"
helm / chartyaml	Chart.yaml	Kubernetes / Helm	top-level version:
pubspecyaml	pubspec.yaml	Dart / Flutter	top-level version:
mixexs	mix.exs	Elixir	version: "…" in def project
gemspec	*.gemspec	Ruby	s.version = "…"
packageswift	Package.swift	Swift	top-level let <name>Version = "…"
cabal	*.cabal	Haskell	top-level version: field
cmake	CMakeLists.txt	C / C++	VERSION argument of project()
gomod	go.mod	Go	git tag only, no file write
txt	VERSION, VERSION.txt	Any	entire file content

Installation

Cargo

cargo install ferrflow

npm

npm install -D ferrflow

Docker

docker run ghcr.io/ferrlabs/ferrflow:latest check

Pre-built binaries

Download from Releases.

Usage

# Preview what would be bumped
ferrflow check
# Run a release
ferrflow release
# Dry run
ferrflow release --dry-run
# Force a specific version (skips commit analysis)
ferrflow release --force-version 2.0.0 # single repo
ferrflow release --force-version api@3.0.0 # monorepo# Pre-release
ferrflow release --channel beta
# Scaffold a config file
ferrflow init
# Scaffold a config file in a specific format
ferrflow init --format json5
# Use a specific config file
ferrflow check --config path/to/ferrflow.toml
# Or set via environment variable
FERRFLOW_CONFIG=path/to/ferrflow.toml ferrflow check
# Print current version
ferrflow version # single repo
ferrflow version api # monorepo, specific package# Print last release tag
ferrflow tag
ferrflow tag api
# JSON output (for scripting)
ferrflow version --json
ferrflow tag --json
# Shell completions
ferrflow completions bash >>~/.bash_completion
ferrflow completions zsh >~/.zfunc/_ferrflow
ferrflow completions fish >~/.config/fish/completions/ferrflow.fish

Pre-generated completion scripts are also available as ferrflow-completions.tar.gz in each GitHub release.

Configuration

FerrFlow looks for a config file at the root of your repository, in this order:

1. ferrflow.json
2. ferrflow.json5
3. ferrflow.toml
4. .ferrflow (dotfile, JSON format)

If multiple config files exist, FerrFlow exits with an error listing the conflicting files. Use --config <path> (or FERRFLOW_CONFIG env var) to specify which one to use. If no config file is found, FerrFlow auto-detects common version files in the current directory.

Run ferrflow init to scaffold a config file interactively. Use --format to skip the format prompt:

ferrflow init # asks which format (default: json)
ferrflow init --format json5
ferrflow init --format toml
ferrflow init --format dotfile # generates .ferrflow

Already using semantic-release? ferrflow migrate reads your existing config and generates the equivalent ferrflow.json:

ferrflow migrate # auto-detects .releaserc
ferrflow migrate --from semantic-release

It maps tagFormat, branches, and the common plugins (changelog, exec, github/gitlab) to their FerrFlow equivalents, and prints a summary of what mapped, what was ignored, and what needs manual review. Anything without a FerrFlow equivalent is surfaced, never guessed. JSON .releaserc is supported today; YAML .releaserc and JS release.config.js are reported as unsupported rather than mis-parsed.

JSON Schema

Add $schema to get autocompletion and validation in VS Code, WebStorm, and any JSON-aware editor:

{
"$schema": "https://ferrflow.com/schema/ferrflow.json"
}

JSON (default)

{
"$schema": "https://ferrflow.com/schema/ferrflow.json",
"workspace": {
"remote": "origin",
"branch": "main"
},
"package": [
{
"name": "my-app",
"path": ".",
"changelog": "CHANGELOG.md",
"versionedFiles": [
{ "path": "package.json", "format": "json" }
]
}
]
}

JSON5

{workspace: {remote: "origin",branch: "main",},package: [{name: "my-app",path: ".",changelog: "CHANGELOG.md",versionedFiles: [{path: "package.json",format: "json"},],},],}

TOML

[workspace]
remote = "origin"branch = "main"
[[package]]
name = "my-app"path = "."changelog = "CHANGELOG.md"
[[package.versioned_files]]
path = "Cargo.toml"format = "toml"

Monorepo

JSON

{
"package": [
{
"name": "api",
"path": "services/api",
"changelog": "services/api/CHANGELOG.md",
"sharedPaths": ["services/shared/"],
"versionedFiles": [
{ "path": "services/api/Cargo.toml", "format": "toml" }
]
},
{
"name": "frontend",
"path": "frontend",
"changelog": "frontend/CHANGELOG.md",
"versionedFiles": [
{ "path": "frontend/package.json", "format": "json" }
]
}
]
}

TOML

[[package]]
name = "api"path = "services/api"changelog = "services/api/CHANGELOG.md"shared_paths = ["services/shared/"]
[[package.versioned_files]]
path = "services/api/Cargo.toml"format = "toml"
[[package]]
name = "frontend"path = "frontend"changelog = "frontend/CHANGELOG.md"
[[package.versioned_files]]
path = "frontend/package.json"format = "json"

Versioning Strategies

Each package can use its own versioning strategy. Set a default at the workspace level and override per package:

[workspace]
versioning = "semver"# default for all packages
[[package]]
name = "api"path = "packages/api"# inherits semver from workspace
[[package]]
name = "site"path = "packages/site"versioning = "calver"# override: date-based

Strategy	Format	Example	Description
semver	MAJOR.MINOR.PATCH	1.4.2	Default, driven by conventional commits
calver	YYYY.M.D	2025.3.28	Date-based, ignores commit types
calver-short	YY.M.D	25.3.28	Compact date-based
calver-seq	YYYY.M.SEQ	2025.3.3	Date + daily sequence counter
sequential	N	42	Simple incrementing build number
zerover	0.MINOR.PATCH	0.15.2	Permanently unstable, never hits 1.0

Tag Template

By default, FerrFlow tags single-repo releases as v1.2.3 and monorepo releases as api@v1.2.3. Customize with tag_template at the workspace or package level using {name} and {version} placeholders.

[workspace]
tag_template = "v{version}"# all packages: v1.2.3
[[package]]
name = "api"path = "packages/api"tag_template = "{name}/v{version}"# override: api/v1.2.3

Layout	Default template	Example tag
Single repo	v{version}	v1.2.3
Monorepo	{name}@v{version}	api@v1.2.3
Custom	release-{version}	release-1.2.3

Pre-release Channels

Publish pre-release versions (alpha, beta, rc, dev) using the --channel flag or branch-based configuration. Pre-release versions follow the format MAJOR.MINOR.PATCH-CHANNEL.IDENTIFIER.

CLI flag

ferrflow release --channel beta # 2.0.0-beta.1
ferrflow check --channel rc # preview pre-release version

Branch-based configuration

Map branches to channels automatically:

{
"workspace": {
"branches": [
{ "name": "main", "channel": false },
{ "name": "develop", "channel": "dev", "prereleaseIdentifier": "timestamp" },
{ "name": "release/*", "channel": "rc" }
]
}
}

Branch names support glob patterns. The first match wins. Wildcards match across / separators, so * matches branches like fix/global and feature/* matches feature/auth/oauth.

Identifier strategies

Strategy	Example	Description
increment	-beta.3	Auto-incrementing counter (default)
timestamp	-dev.20250402T1430	UTC timestamp
short-hash	-dev.a1b2c3d	Git short hash
timestamp-hash	-dev.20250402T1430-a1b2c3d	Timestamp + hash

Behavior

• Floating tags (e.g. v1, v1.2) are never moved by pre-release versions
• GitHub Releases are marked as pre-release
• Stable releases include all commits since the last stable tag (skipping pre-release tags)
• Hook environment includes FERRFLOW_CHANNEL and FERRFLOW_IS_PRERELEASE

Release Commit Mode

Controls how FerrFlow commits version bumps and changelog updates after a release.

[workspace]
release_commit_mode = "commit"# default

Mode	Description
commit	Push a release commit directly to the branch
pr	Create a pull request with the release changes
none	Skip committing entirely (useful when another tool handles it)

When using pr mode, auto_merge_releases controls whether the PR is automatically merged:

[workspace]
release_commit_mode = "pr"auto_merge_releases = true# default

Release Commit Scope

In monorepo mode, controls whether all package bumps go into a single commit or one commit per package:

[workspace]
release_commit_scope = "grouped"# default

Scope	Description
grouped	Single commit for all packages (e.g. chore(release): api v1.0.0, site v2.1.0)
per-package	One commit per package (e.g. chore(release): api v1.0.0, then chore(release): site v2.1.0)

Per-package commits make it easier to revert a single package bump without affecting others. This works with both commit and pr release modes.

Skip CI

By default, release commits in commit mode include [skip ci] in the message to avoid triggering a CI loop. Override with skip_ci:

[workspace]
skip_ci = false# force CI to run on release commits

In pr mode, skip_ci defaults to false since the PR merge triggers CI naturally.

Floating Tags

Move abbreviated tags (e.g. v1, v1.2) to always point at the latest matching release:

[workspace]
floating_tags = ["major"] # creates/moves v1 when releasing v1.2.3

Level	Tag	Points to
major	v1	Latest v1.x.x
minor	v1.2	Latest v1.2.x

Floating tags are never moved by pre-release versions. Override per package:

[[package]]
name = "api"path = "packages/api"floating_tags = ["major", "minor"]

Orphaned Tag Strategy

After a rebase + force-push, existing tags may point to commits that no longer exist on the branch. orphaned_tag_strategy controls how FerrFlow handles this:

[workspace]
orphaned_tag_strategy = "warn"# default

Strategy	Description
warn	Log a warning and skip the orphaned tag
treeHash	Attempt recovery by matching the commit's tree hash
message	Attempt recovery by matching the commit message

Recover Missed Releases

In monorepos, a package can miss a release if its files changed but FerrFlow wasn't run. Enable recover_missed_releases to compare files against the last tag instead of just the last commit:

[workspace]
recover_missed_releases = true# default: false

Package Dependencies

In a monorepo, use depends_on to automatically patch-bump a package when one of its dependencies is released:

{
"package": [
{ "name": "core", "path": "packages/core" },
{
"name": "cli",
"path": "packages/cli",
"depends_on": ["core"]
}
]
}

When core is bumped, cli gets a patch bump even if it had no direct commits.

Hooks

Run shell commands at lifecycle points during a release. Hooks can be set at the workspace level (applies to all packages) or per package:

[workspace.hooks]
pre_bump = "echo 'about to bump'"post_bump = "cargo check"pre_commit = "npm run build"pre_publish = "npm pack --dry-run"post_publish = "notify-slack.sh"on_failure = "abort"# or "continue"

Hook	When
pre_bump	After bump calculation, before writing version files
post_bump	After writing version files, before changelog generation
pre_commit	After changelog generation, before git commit
pre_publish	After commit and tag, before push
post_publish	After push and release creation

If a hook exits non-zero and on_failure is abort (default), the release is cancelled. Set on_failure to continue to ignore hook failures.

Hook commands receive environment variables: FERRFLOW_PACKAGE, FERRFLOW_OLD_VERSION, FERRFLOW_NEW_VERSION, FERRFLOW_BUMP_TYPE, FERRFLOW_TAG, FERRFLOW_PACKAGE_PATH, FERRFLOW_DRY_RUN, FERRFLOW_CHANNEL, FERRFLOW_IS_PRERELEASE.

Conventional Commits

FerrFlow follows the Conventional Commits spec.

Prefix	Bump
fix:, perf:, refactor:	patch
feat:	minor
feat!:, BREAKING CHANGE	major
chore:, docs:, ci:	none

CI usage

GitLab CI

release:
image: ghcr.io/ferrlabs/ferrflow:latestscript:
- ferrflow releaserules:
- if: '$CI_COMMIT_BRANCH == "main"'

GitHub Actions

- name: Releaserun: ferrflow releaseenv:
GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Using the hosted bot (ferrflow[bot])

Install the FerrFlow GitHub App on your repo or org, then opt in with bot: true. Release commits, tags, and GitHub Releases are authored by ferrflow[bot] and downstream workflows triggered by those events run normally (unlike the default GITHUB_TOKEN, which suppresses them).

permissions:
id-token: writecontents: readsteps:
- uses: actions/checkout@v6with:
fetch-depth: 0
- uses: FerrLabs/FerrFlow@v7with:
bot: true

That is the whole job. No setup-node, no extra dependencies. FerrFlow's Rust binary handles the OIDC exchange directly, so minimal self-hosted runners work out of the box.

Three auth modes are supported: bot: true uses the hosted FerrFlow App (recommended); token: <PAT> uses a personal access token or your own GitHub App token (DIY); omitting both falls back to the workflow's GITHUB_TOKEN (simplest, but release events won't trigger downstream workflows).

License

MIT