diff --git a/.gitignore b/.gitignore
index 24aefa7e67143ebf670d39dabf8019544fa16e3d..4fe95707856e7e77551421c8cb6bb232e1382ce9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,3 +20,4 @@ git-env
 /gitaly-debug
 /praefect
 gitaly.pid
+/gitaly-bundle-apply
diff --git a/cmd/gitaly-bundle-apply/main.go b/cmd/gitaly-bundle-apply/main.go
new file mode 100644
index 0000000000000000000000000000000000000000..132caa0d7ac9b1d18611c521383c7e2c7a4af1a7
--- /dev/null
+++ b/cmd/gitaly-bundle-apply/main.go
@@ -0,0 +1,126 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func main() {
+	if err := _main(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func _main() error {
+	r := bufio.NewReader(os.Stdin)
+
+	line, err := readLine(r)
+	if err != nil {
+		return err
+	}
+
+	const header = "# gitaly bundle v1"
+	if line != header {
+		return fmt.Errorf("invalid header %q", line)
+	}
+
+	// Ref dump is at the head of the bundle so we must consume it first
+	newRefs, err := refMapFromReader(r)
+	if err != nil {
+		return err
+	}
+
+	// There may not be a pack file, for instance if the only change is a ref deletion.
+	const magic = "PACK"
+	if b, err := r.Peek(len(magic)); err == nil && string(b) == magic {
+		// TODO use --keep to prevent concurrent repack/gc from deleting this
+		// packfile before we apply the ref update below?
+		indexPack := exec.Command("git", "index-pack", "--stdin", "--fix-thin")
+		indexPack.Stdin = r
+		indexPack.Stdout = os.Stderr
+		indexPack.Stderr = os.Stderr
+
+		if err := indexPack.Run(); err != nil {
+			return err
+		}
+	}
+
+	oldRefs, err := currentRefs()
+	if err != nil {
+		return err
+	}
+
+	refUpdate := &bytes.Buffer{}
+	for ref, oid := range newRefs {
+		fmt.Fprintf(refUpdate, "update %s %s\n", ref, oid)
+	}
+
+	for ref := range oldRefs {
+		if _, ok := newRefs[ref]; ok {
+			continue
+		}
+		fmt.Fprintf(refUpdate, "delete %s\n", ref)
+	}
+
+	updateRef := exec.Command("git", "update-ref", "--stdin")
+	updateRef.Stdin = refUpdate
+	updateRef.Stdout = os.Stderr
+	updateRef.Stderr = os.Stderr
+
+	if err := updateRef.Run(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func readLine(r *bufio.Reader) (string, error) {
+	b, err := r.ReadBytes('\n')
+	if err != nil {
+		return "", err
+	}
+
+	return string(b)[:len(b)-1], err
+}
+
+func currentRefs() (map[string]string, error) {
+	cmd := exec.Command("git", "for-each-ref", "--format=%(objectname) %(refname)")
+	cmd.Stderr = os.Stderr
+	out, err := cmd.Output()
+	if err != nil {
+		return nil, err
+	}
+
+	refs, err := refMapFromReader(bufio.NewReader(bytes.NewReader(out)))
+	if err == io.EOF {
+		err = nil
+	}
+
+	return refs, err
+}
+
+func refMapFromReader(r *bufio.Reader) (map[string]string, error) {
+	result := make(map[string]string)
+	var err error
+
+	for {
+		line, err := readLine(r)
+		if err != nil || line == "" {
+			break
+		}
+
+		split := strings.SplitN(line, " ", 2)
+		if len(split) != 2 {
+			return nil, fmt.Errorf("invalid ref line %q", line)
+		}
+		result[split[1]] = split[0]
+	}
+
+	return result, err
+}
diff --git a/gitaly-bundle-create b/gitaly-bundle-create
new file mode 100755
index 0000000000000000000000000000000000000000..e95b0d1cdae93f6fcf896bb4c578fbf602e8e38f
--- /dev/null
+++ b/gitaly-bundle-create
@@ -0,0 +1,26 @@
+#!/bin/sh
+
+set -ex
+
+ref_snapshot=$(mktemp -t gitaly-bundle-create.XXXXXX)
+
+# Header
+echo '# gitaly bundle v1'
+
+# Ref dump
+git for-each-ref --format='%(objectname) %(refname)' | tee "${ref_snapshot}"
+echo
+
+(
+  # Tell pack-objects the objects we want to include
+  awk '{print $1}' "${ref_snapshot}"
+  rm "${ref_snapshot}"
+
+  # The previous snapshot should be on stdin. Use it to tell pack-objects
+  # which objects we already have. The previous snapshot may be empty
+  # (/dev/null). This awk command will only consume the ref dump part of
+  # stdin; pack data is not read.
+  awk '/^$/ { exit } /^[^#]/ { print $1 }' |\
+    git cat-file --batch-check='%(objectname)' |\
+    awk '!/ missing$/ { print "^" $1 }'
+) | git pack-objects --thin --stdout --non-empty --delta-base-offset