gig

I wanted to learn how Git works under the hood, so I built gig (Git-in-Go) - a simple Git implementation written in Go.

It isn't a wrapper around the git command line tool. It creates standard Git objects (blobs, trees, commits), compresses them with zlib, hashes them with SHA-1, and updates .git/refs/heads/main directly.

Since it uses Git's exact file structure and object formats, you can run gig inside a standard Git repository, or check gig commits using official Git.

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Under the hood

Just Go and its standard library:

• Go: For fast execution and single binary builds
• Cobra (spf13/cobra): For CLI flags and subcommands
• crypto/sha1: Computes standard 40-character Git object IDs
• compress/zlib: Reads and writes compressed Git object files in .git/objects/

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Installing it globally

Options to install gig globally across Linux, macOS, or Windows:

1. Using Go (go install)

If you have Go installed:

go install github.com/devxdh/gig@latest

(Make sure $GOPATH/bin or ~/go/bin is in your PATH.)

2. One-liner shell script (Linux / macOS / WSL)

curl -fsSL https://raw.githubusercontent.com/devxdh/gig/main/install.sh | bash

3. Direct binary download

Grab precompiled binaries for Linux, macOS, or Windows directly from GitHub Releases.

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Usage

Here is how a basic workflow looks:

# 1. Initialize a repository (creates .git directory & main branch ref)
gig init my-project
cd my-project

# 2. Add a file to gig's object store (creates a blob object)
echo "Hello world" > main.txt
gig hash-object -w main.txt

# 3. Take a snapshot of the directory (creates a tree object)
gig write-tree

# 4. Create a commit
gig commit -m "Initial commit"

# 5. View commit history
gig log

Branches & Checkout

# List branches
gig branch

# Create a new branch
gig branch feature

# Switch branches
gig checkout feature

Low-level plumbing commands

Commands for inspecting Git objects:

• gig cat-file -p <hash>: Print object contents (blob, tree, or commit)
• gig cat-file -t <hash>: Print object type (blob, tree, or commit)
• gig ls-tree <hash>: List items in a tree object
• gig commit-tree <tree-hash> -m "msg" -p <parent-hash>: Create a commit object manually

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Using Gig and official Git together (Hybrid mode)

Because gig writes standard Git objects, you can use it alongside official git on the exact same project:

# Initialize a repo with gig
gig init hybrid-demo
cd hybrid-demo
echo "made with gig" > file.txt
gig commit -m "Commit 1 from gig"

# Now run real Git in the exact same folder - Git reads gig's commits cleanly
git log
git status

# Add another commit using real Git
echo "added with real git" >> file.txt
git commit -am "Commit 2 from real git"

# Check log again with gig
gig log --oneline

Both tools read from and write to .git/objects and .git/refs/heads/main.

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Building from source

git clone https://github.com/devxdh/gig.git
cd gig

make build    # builds binary to ./bin/gig
make install  # installs binary globally to system PATH
make test     # runs unit tests

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License

MIT.