README

A pure-PHP Git client and server. Commits, branches, diffs, HTTP push/pull — all without shelling out to git.

Why this exists

Git is a useful storage model even when a server cannot run the git binary: snapshots, branches, object-addressed files, diffs, merges, and sync over HTTP. That matters for WordPress tools that want revision history for generated files, content snapshots, site state, or collaborative edits in constrained runtimes.

The Git component implements the core repository operations in PHP and stores objects through the toolkit Filesystem interface. That means the same repository can live on disk, in memory, or in another backend, and higher-level code can commit files without knowing where objects are stored.

The docs start with simple commits because that mental model scales: a repository is just objects plus refs. From there, branches, history walking, root commits, and merges become details you can reason about instead of magic shell behavior.

Choose it for tests, browser-like sandboxes, hosted WordPress environments, and applications that need Git behavior through PHP APIs instead of shell commands.

Commit files into an in-memory repo

The simplest possible repository: an InMemoryFilesystem as object storage and one commit() call. Reach for this in tests, in WP-CLI snapshots, or any place you want versioning without touching disk.

<?php
require '/wordpress/wp-content/php-toolkit/vendor/autoload.php';

use WordPress\Filesystem\InMemoryFilesystem;
use WordPress\Git\GitRepository;

$repo = new GitRepository( InMemoryFilesystem::create() );

$oid = $repo->commit( array(
	'updates' => array(
		'README.md'           => "# My Project\n",
		'src/hello-world.php' => '<?php echo "Hello!";',
	),
) );

echo "commit: {$oid}\n";
echo "HEAD:   " . $repo->get_branch_tip( 'HEAD' ) . "\n";
echo "README: " . $repo->read_object_by_path( '/README.md' )->consume_all();

commit: <oid>
HEAD: <oid>
README: # My Project

Walk the commit history

Follow the parent chain from HEAD backwards. Building block for a WP-CLI "post revisions" log or a "what changed since release X" report.

<?php
require '/wordpress/wp-content/php-toolkit/vendor/autoload.php';

use WordPress\Filesystem\InMemoryFilesystem;
use WordPress\Git\GitRepository;
use WordPress\Git\Model\Commit;

$repo = new GitRepository( InMemoryFilesystem::create() );
foreach ( array( 'add intro', 'fix typo', 'expand examples' ) as $i => $msg ) {
	$repo->commit( array(
		'updates' => array( 'post.md' => "# Draft {$i}" ),
		'commit'  => array( 'message' => $msg ),
	) );
}

$oid = $repo->get_branch_tip( 'HEAD' );
while ( ! Commit::is_null_hash( $oid ) ) {
	$c = $repo->read_object( $oid )->as_commit();
	echo substr( $c->hash, 0, 7 ) . '  ' . trim( $c->message ) . "\n";
	$oid = $c->get_first_parent_hash();
	if ( ! $oid || ! $repo->has_object( $oid ) ) break;
}

<hash>  expand examples
<hash>  fix typo
<hash>  add intro

Treat a repository like a filesystem

GitFilesystem wraps a repository in this toolkit's Filesystem interface. With the default options, each put_contents() records a new commit.

<?php
require '/wordpress/wp-content/php-toolkit/vendor/autoload.php';

use WordPress\Filesystem\InMemoryFilesystem;
use WordPress\Git\GitFilesystem;
use WordPress\Git\GitRepository;

$repo = new GitRepository( InMemoryFilesystem::create() );
$fs   = GitFilesystem::create( $repo );

$fs->put_contents( '/posts/hello.md', "# Hello\nFirst draft." );
$fs->put_contents( '/posts/about.md', "# About\nWho we are." );
$fs->put_contents( '/posts/hello.md', "# Hello\nSecond draft." );

echo "tree:\n";
foreach ( $fs->ls( '/posts' ) as $name ) {
	echo "  /posts/{$name}\n";
}
echo "\nhello.md now:\n" . $fs->get_contents( '/posts/hello.md' ) . "\n";

tree:
  /posts/about.md
  /posts/hello.md

hello.md now:
# Hello
Second draft.

Branch, edit, and switch back

Create a feature branch off the current commit, change files, flip HEAD back. Useful for experimental edits in collaborative tools.

<?php
require '/wordpress/wp-content/php-toolkit/vendor/autoload.php';

use WordPress\Filesystem\InMemoryFilesystem;
use WordPress\Git\GitRepository;

$repo = new GitRepository( InMemoryFilesystem::create() );
$base = $repo->commit( array(
	'updates' => array( 'config.json' => '{"flag":false}' ),
	'commit'  => array( 'message' => 'baseline' ),
) );

$repo->create_branch( 'refs/heads/experiment', $base );
$repo->checkout( 'refs/heads/experiment' );
$repo->commit( array(
	'updates' => array( 'config.json' => '{"flag":true}' ),
	'commit'  => array( 'message' => 'flip the flag' ),
) );

echo "on experiment: " . $repo->read_object_by_path( '/config.json' )->consume_all() . "\n";

$repo->checkout( 'refs/heads/trunk' );
echo "on trunk:      " . $repo->read_object_by_path( '/config.json' )->consume_all() . "\n";

on experiment: {"flag":true}
on trunk:      {"flag":false}

Three-way merge two branches

The classic Git workflow: branch off, edit on each side, merge. $repo->merge() finds the common ancestor, three-way-merges every file, and creates a merge commit.

<?php
require '/wordpress/wp-content/php-toolkit/vendor/autoload.php';

use WordPress\Filesystem\InMemoryFilesystem;
use WordPress\Git\GitRepository;

$repo = new GitRepository( InMemoryFilesystem::create() );
$base = $repo->commit( array( 'updates' => array(
	'todo.txt' => "buy milk\nwalk dog\nread book\n",
) ) );

$repo->commit( array( 'updates' => array(
	'todo.txt' => "buy oat milk\nwalk dog\nread book\n",
) ) );

$repo->create_branch( 'refs/heads/feature', $base );
$repo->checkout( 'refs/heads/feature' );
$repo->commit( array( 'updates' => array(
	'todo.txt' => "buy milk\nwalk dog\nread book\nwrite blog post\n",
) ) );

$repo->checkout( 'refs/heads/trunk' );
$result = $repo->merge( 'refs/heads/feature' );

echo "merge head: {$result['new_head']}\n";
echo "conflicts:  " . ( $result['conflicts'] ? implode( ',', $result['conflicts'] ) : 'none' ) . "\n";
echo "result:\n" . $repo->read_object_by_path( '/todo.txt' )->consume_all();

merge head: <oid>
conflicts:  none
result:
buy oat milk
walk dog
read book
write blog post

Snapshot WordPress options into a repo

Serialize a chunk of WP state (options, post meta, a theme config) on every save and commit it. You get free history, diffs between snapshots, and a "rollback to last week" button.

<?php
require '/wordpress/wp-content/php-toolkit/vendor/autoload.php';

use WordPress\Filesystem\InMemoryFilesystem;
use WordPress\Git\GitRepository;

$repo = new GitRepository( InMemoryFilesystem::create() );

$snapshots = array(
	array( 'blogname' => 'My Site',  'posts_per_page' => 10, 'timezone_string' => 'UTC' ),
	array( 'blogname' => 'My Site',  'posts_per_page' => 20, 'timezone_string' => 'UTC' ),
	array( 'blogname' => 'New Name', 'posts_per_page' => 20, 'timezone_string' => 'Europe/Warsaw' ),
);

foreach ( $snapshots as $i => $options ) {
	$repo->commit( array(
		'updates' => array( 'options.json' => json_encode( $options, JSON_PRETTY_PRINT ) ),
		'commit'  => array( 'message' => "snapshot #{$i}" ),
	) );
}

$head    = $repo->get_branch_tip( 'HEAD' );
$parent  = $repo->read_object( $head )->as_commit()->get_first_parent_hash();
$diff    = $repo->diff_commits( $head, $parent );

echo "Files changed in last snapshot:\n";
foreach ( $diff as $name => $entry ) {
	echo "  {$name}\n";
}

Files changed in last snapshot:
  options.json