Tags

Tags are references in Git repositories.
They are used to mark specific points in a repo's history.

They typically denote the version that a progarm is on, usually following the semantic versioning standard.

Tags are immutable references to specific commits.

Use Cases

• Marking software versions (e.g., v2.1.3)
• Marking release candidates or stable builds
• Creating release notes from tag history

Most tags follow Semantic Versioning (semver): MAJOR.MINOR.PATCH, e.g., v.2.1.3.

Types of Tags

There are two types of tags:

1. Lightweight Tags

   • Lightweight tags are simple pointers to a commit.
   • These are simple names pointing directly to a commit (like a bookmark).
   • These contain no metadata. No tagger info, message, or date.
   • Stored as a file containing the commit SHA in .git/refs/tags

2. Annotated Tags

   • Annotated tags include additional metdata (e.g., the tagger's name, email, and a message).
   • Contains the date and tag message, optionally signed by a GPG key.
   • Stored as a full git object in .git/objects/

Using git tag

The git tag command is used to manage the tags for repositories.

Adding a Lightweight Tag

To add a tag to a repository, simply use git tag <tagname>:

git tag v1.0.0

Verify by running git tag with no arguments:

git tag
# Output:
# v1.0.0

This creates a lightweight tag, which is tied to the current commit, and will persist until the next tag is set.

Adding an Annotated Tag

Use -a to specify an annotated tag, and -m to specify a message.

git tag -a v1.0.0 -m "Initial release of version 1.0.0"

Use -s for GPG signing (or SSH signing if configured).

git tag -s v1.0.0 -m "Signed release"

Listing Tags

List tags using git tag with no arguments.

git tag

Filter tags by version by using -l and a pattern.

git tag -l "v1.*"

View Tag Details

Show metadata and the tagged commit with git show and the tag name.

git show v1.0.0