GitHub Slug Action

This GitHub Action exposes slug and short values of GitHub environment variables inside your workflow.

Quick Start

steps:
  - uses: actions/checkout@v6
  - name: Inject enhanced GitHub environment variables
    uses: rlespinasse/github-slug-action@v5

Caution

Use Dependabot to maintain your github-slug-action version updated in your GitHub workflows.

What It Does

• SLUG -- Lowercase, replace special characters with -, limit to 63 characters. Dots and underscores preserved.
• SLUG_URL -- Same as SLUG, but dots and underscores are also replaced. Safe for URLs and subdomains.
• SHORT -- Shorten Git SHA values to a unique prefix.
• PART -- Extract portions of a variable (e.g., owner or repository name from GITHUB_REPOSITORY).
• _CS -- Case-sensitive variants of SLUG and SLUG_URL (original casing preserved).

Tip

Read the slug transformation rules for the full algorithm and rationale.

Inputs

Input	Default	Description
prefix	""	Value prepended to each generated variable name
slug-maxlength	63	Max length of slugified values ("nolimit" to disable)
short-length	(Git default)	Length of short SHA values (minimum 4)

See the inputs reference for details.

Available Variables

Variable	Type	Description
GITHUB_REF_POINT	Enhanced	Branch or tag name (consistent across event types)
GITHUB_REPOSITORY_OWNER_PART	Partial	Owner extracted from repository
GITHUB_REPOSITORY_NAME_PART	Partial	Repository name extracted from repository
GITHUB_REPOSITORY_SLUG	Slug	The owner and repository name
GITHUB_REF_SLUG	Slug	The branch or tag ref
GITHUB_REF_NAME_SLUG	Slug	The branch or tag name shown on GitHub
GITHUB_HEAD_REF_SLUG	Slug	PR head branch
GITHUB_BASE_REF_SLUG	Slug	PR base branch
GITHUB_EVENT_REF_SLUG	Slug	Webhook Git ref
GITHUB_SHA_SHORT	Short	Shortened commit SHA
GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT	Short	Shortened PR head commit SHA

All slug variables also have _SLUG_URL and _CS variants. See the full variable reference.

Tip

If you don't find what you need, read about available GitHub variables, propose a new variable, or use slugify-value / shortify-git-revision directly.

Documentation

Tutorial

• Getting started -- Step-by-step guide for first-time users

How-To Guides

• Use a prefix
• Configure slug max length
• Configure short SHA length
• Use slug variables in URLs
• More workflow examples (OS-specific usage, URL patterns)

Reference

• Variable reference -- All variables with transformation examples
• Inputs reference -- Action inputs specification
• GitHub variables by event -- Which variables are available per event type

Explanation

• Slug transformation rules -- How and why transformations work

Migration

• Migrate from v4 to v5 -- GITHUB_REF_NAME behaviour changed on pull request events
• Migrate from v3 to v4 -- Short SHA length is now determined by Git

Troubleshooting

See the troubleshooting guide for common issues and solutions.

Thanks for talking about us

In English 🇬🇧

• Action spotlight by Michael Heap
• Serverless Deploy Previews on GitHub Actions
• Let's Build a Continuous Delivery and Branching Process with GitHub Actions, Vercel and Heroku
• Celebrating 5 Years of github-slug-action on sfeir.dev

In French 🇫🇷

• Mettre en place une CI/CD Angular avec GitHub Actions & Netlify
• GitHub Actions : enfin des pipelines accessibles aux développeurs
• GitHub-slug-action : 5 ans d'open source pour cette GitHub Action essentielle au CI/CD

In Chinese 🇨🇳

• 利用github-slug-action暴漏GitHub Action上下文中的关键变量

The next one is you. Don't hesitate to add yourself to one of these lists.