diff --git a/README.md b/README.md
index 43fc6e6..ebe830f 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,14 @@ You also need the agent to have access to the following defined environment vari
 
 Setting the `BUILDKITE_PLUGIN_S3_CACHE_ONLY_SHOW_ERRORS` environment variable will reduce logging of file operations towards S3.
 
+### `compression` (string, optional)
+
+Allows for the cached file/folder to be saved/restored as a single file. You will need to make sure to use the same compression when saving and restoring or it will cause a cache miss.
+
+Assuming the underlying executables are available, the allowed values are:
+* `tgz`: `tar` with gzip compression
+* `zip`: `(un)zip` compression
+
 ### `manifest` (string, required if using `file` caching level)
 
 A path to a file or folder that will be hashed to create file-level caches.
diff --git a/hooks/post-checkout b/hooks/post-checkout
index d8689ca..05db6ab 100755
--- a/hooks/post-checkout
+++ b/hooks/post-checkout
@@ -22,7 +22,23 @@ elif [ "${MAX_LEVEL}" = 'file' ] && [ -z "$(plugin_read_config MANIFEST)" ]; the
   exit 1
 fi
 
-build_key "${MAX_LEVEL}" "${RESTORE_PATH}" # to validate the level
+COMPRESS=$(plugin_read_config COMPRESSION 'none')
+if ! validate_compression "${COMPRESS}"; then
+  echo "+++ 🚨 Invalid value for compression option"
+  exit 1
+fi
+
+build_key "${MAX_LEVEL}" "${RESTORE_PATH}" >/dev/null # to validate the level
+
+ACTUAL_PATH=$(mktemp)
+
+if [ "${COMPRESS}" = 'tgz' ]; then
+  UNCOMPRESS_COMMAND=(tar xzf)
+elif [ "${COMPRESS}" = 'zip' ]; then
+  UNCOMPRESS_COMMAND=(unzip)
+else
+  ACTUAL_PATH="${RESTORE_PATH}"
+fi
 
 SORTED_LEVELS=(file step branch pipeline all)
 
@@ -31,10 +47,16 @@ for CURRENT_LEVEL in "${SORTED_LEVELS[@]}"; do
     continue
   fi
 
-  KEY=$(build_key "${CURRENT_LEVEL}" "${RESTORE_PATH}")
+  KEY=$(build_key "${CURRENT_LEVEL}" "${RESTORE_PATH}" "${COMPRESS}")
   if backend_exec exists "${KEY}"; then
     echo "Cache hit at ${CURRENT_LEVEL} level, restoring ${RESTORE_PATH}..."
-    backend_exec get "${KEY}" "${RESTORE_PATH}"
+    backend_exec get "${KEY}" "${ACTUAL_PATH}"
+
+    if [ "${COMPRESS}" != 'none' ]; then
+      echo "Cache is compressed, uncompressing..."
+      "${UNCOMPRESS_COMMAND[@]}" "${ACTUAL_PATH}" "${RESTORE_PATH}"
+    fi
+
     exit 0
   elif [ "${CURRENT_LEVEL}" = "${MAX_LEVEL}" ]; then
     echo "Cache miss up to ${CURRENT_LEVEL}-level, sorry"
diff --git a/hooks/post-command b/hooks/post-command
index 1ad5d82..a7ed1f9 100755
--- a/hooks/post-command
+++ b/hooks/post-command
@@ -22,7 +22,27 @@ elif [ "${LEVEL}" = 'file' ] && [ -z "$(plugin_read_config MANIFEST)" ]; then
   exit 1
 fi
 
-KEY=$(build_key "${LEVEL}" "${CACHE_PATH}")
+COMPRESS=$(plugin_read_config COMPRESSION 'none')
+if ! validate_compression "${COMPRESS}"; then
+  echo "+++ 🚨 Invalid value for compression option"
+  exit 1
+fi
+
+KEY=$(build_key "${LEVEL}" "${CACHE_PATH}" "${COMPRESS}")
+
+if [ "${COMPRESS}" = 'tgz' ]; then
+  COMPRESS_COMMAND=(tar czf)
+elif [ "${COMPRESS}" = 'zip' ]; then
+  COMPRESS_COMMAND=(zip)
+fi
+
+if [ "${COMPRESS}" != 'none' ]; then
+  echo "Compressing ${CACHE_PATH} with ${COMPRESS}..."
+  ACTUAL_PATH=$(mktemp)
+  "${COMPRESS_COMMAND[@]}" "${ACTUAL_PATH}" "${CACHE_PATH}"
+else
+  ACTUAL_PATH="${CACHE_PATH}"
+fi
 
 echo "Saving ${LEVEL}-level cache of ${CACHE_PATH}"
-backend_exec save "${KEY}" "${CACHE_PATH}"
\ No newline at end of file
+backend_exec save "${KEY}" "${ACTUAL_PATH}"
\ No newline at end of file
diff --git a/lib/shared.bash b/lib/shared.bash
index 006baeb..2ee3185 100644
--- a/lib/shared.bash
+++ b/lib/shared.bash
@@ -36,7 +36,7 @@ hash_files() {
 build_key() {
   local LEVEL="$1"
   local CACHE_PATH="$2"
-  local BASE
+  local COMPRESSION="${3:-}"
 
   if [ "${LEVEL}" = 'file' ]; then
     BASE="$(hash_files "$(plugin_read_config MANIFEST)")"
@@ -53,7 +53,7 @@ build_key() {
     exit 1
   fi
 
-  echo "cache-${LEVEL}-${BASE}-${CACHE_PATH}" | "$(sha)" | cut -d\  -f1
+  echo "cache-${LEVEL}-${BASE}-${CACHE_PATH}-${COMPRESSION}" | "$(sha)" | cut -d\  -f1
 }
 
 backend_exec() {
@@ -61,4 +61,17 @@ backend_exec() {
   BACKEND_NAME=$(plugin_read_config BACKEND 'fs')
 
   PATH="${PATH}:${DIR}/../backends" "cache_${BACKEND_NAME}" "$@"
+}
+
+validate_compression() {
+  local COMPRESSION="$1"
+
+  VALID_COMPRESSIONS=(none tgz zip)
+  for VALID in "${VALID_COMPRESSIONS[@]}"; do
+    if [ "${COMPRESSION}" = "${VALID}" ]; then
+      return 0
+    fi
+  done
+
+  return 1
 }
\ No newline at end of file
diff --git a/plugin.yml b/plugin.yml
index f1657f5..30c7f7b 100644
--- a/plugin.yml
+++ b/plugin.yml
@@ -6,10 +6,16 @@ configuration:
   properties:
     backend:
       type: string
-    path:
+    compression:
       type: string
+      enum:
+        - zip
+        - tar
+        - tgz
     manifest:
       type: string
+    path:
+      type: string
     restore:
       type: string
       enum:
diff --git a/tests/post-checkout-tgz.bats b/tests/post-checkout-tgz.bats
new file mode 100644
index 0000000..9e07e57
--- /dev/null
+++ b/tests/post-checkout-tgz.bats
@@ -0,0 +1,157 @@
+#!/usr/bin/env bats
+
+# To debug stubs, uncomment these lines:
+# export CACHE_DUMMY_STUB_DEBUG=/dev/tty
+# export TAR_STUB_DEBUG=/dev/tty
+
+setup() {
+  load "${BATS_PLUGIN_PATH}/load.bash"
+
+  mkdir -p tests/data/my_files
+  echo "all the llamas" > "tests/data/my_files/llamas.txt"
+  echo "no alpacas" > "tests/data/my_files/alpacas.txt"
+
+  export BUILDKITE_PLUGIN_CACHE_BACKEND=dummy
+  export BUILDKITE_PLUGIN_CACHE_COMPRESSION=tgz
+  export BUILDKITE_PLUGIN_CACHE_PATH=tests/data/my_files
+  export BUILDKITE_PLUGIN_CACHE_MANIFEST=tests/data/my_files/llamas.txt
+
+  # necessary for key-calculations
+  export BUILDKITE_LABEL="step-label"
+  export BUILDKITE_BRANCH="tests"
+  export BUILDKITE_ORGANIZATION_SLUG="bk-cache-test"
+  export BUILDKITE_PIPELINE_SLUG="cache-pipeline"
+
+  # stub is the same for all tests
+  stub tar \
+    "xzf \* \* : echo uncompressed \$2 into \$3"
+}
+
+teardown() {
+  rm -rf tests/data
+
+  unstub tar
+}
+
+@test 'Existing file-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=file
+
+  stub cache_dummy \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at file level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
+
+@test 'Existing file-based restore even when max-level is higher' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at file level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
+
+@test 'Existing step-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=step
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at step level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
+
+@test 'Existing branch-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=branch
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at branch level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
+@test 'Existing pipeline-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=pipeline
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at pipeline level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
+
+@test 'Existing all-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at all level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
+
+@test 'Existing lower level restore works' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at branch level'
+  assert_output --partial 'Cache is compressed, uncompressing...'
+
+  unstub cache_dummy
+}
\ No newline at end of file
diff --git a/tests/post-checkout-zip.bats b/tests/post-checkout-zip.bats
new file mode 100644
index 0000000..c5cbb3d
--- /dev/null
+++ b/tests/post-checkout-zip.bats
@@ -0,0 +1,158 @@
+#!/usr/bin/env bats
+
+# To debug stubs, uncomment these lines:
+# export CACHE_DUMMY_STUB_DEBUG=/dev/tty
+# export UNZIP_STUB_DEBUG=/dev/tty
+
+setup() {
+  load "${BATS_PLUGIN_PATH}/load.bash"
+
+  mkdir -p tests/data/my_files
+  echo "all the llamas" > "tests/data/my_files/llamas.txt"
+  echo "no alpacas" > "tests/data/my_files/alpacas.txt"
+
+  export BUILDKITE_PLUGIN_CACHE_BACKEND=dummy
+  export BUILDKITE_PLUGIN_CACHE_COMPRESSION=zip
+  export BUILDKITE_PLUGIN_CACHE_PATH=tests/data/my_files
+  export BUILDKITE_PLUGIN_CACHE_MANIFEST=tests/data/my_files/llamas.txt
+
+  # necessary for key-calculations
+  export BUILDKITE_LABEL="step-label"
+  export BUILDKITE_BRANCH="tests"
+  export BUILDKITE_ORGANIZATION_SLUG="bk-cache-test"
+  export BUILDKITE_PIPELINE_SLUG="cache-pipeline"
+
+  # stub is the same for all tests
+  stub unzip \
+    "\* \* : echo uncompressed \$2 into \$3"
+}
+
+teardown() {
+  rm -rf tests/data
+
+  unstub unzip
+}
+
+@test 'Existing file-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=file
+
+  stub cache_dummy \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at file level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
+
+@test 'Existing file-based restore even when max-level is higher' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at file level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
+
+@test 'Existing step-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=step
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at step level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
+
+@test 'Existing branch-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=branch
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at branch level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
+@test 'Existing pipeline-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=pipeline
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at pipeline level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
+
+@test 'Existing all-based restore' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at all level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
+
+
+@test 'Existing lower level restore works' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at branch level'
+  assert_output --partial "Cache is compressed, uncompressing..."
+
+  unstub cache_dummy
+}
\ No newline at end of file
diff --git a/tests/post-checkout.bats b/tests/post-checkout.bats
index 253d3a1..07d0ae4 100644
--- a/tests/post-checkout.bats
+++ b/tests/post-checkout.bats
@@ -50,6 +50,16 @@ teardown() {
   assert_output --partial 'Invalid cache level'
 }
 
+@test "Invalid compression level fails" {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+  export BUILDKITE_PLUGIN_CACHE_COMPRESSION=invalid
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_failure
+  assert_output --partial 'Invalid value for compression option'
+}
+
 @test 'File-based cache with no manifest fails' {
   export BUILDKITE_PLUGIN_CACHE_RESTORE=file
   unset BUILDKITE_PLUGIN_CACHE_MANIFEST
@@ -234,7 +244,7 @@ teardown() {
   unstub cache_dummy
 }
 
-@test 'Existing all-based restore does nothing' {
+@test 'Existing all-based restore' {
   export BUILDKITE_PLUGIN_CACHE_RESTORE=all
 
   stub cache_dummy \
@@ -250,5 +260,22 @@ teardown() {
   assert_success
   assert_output --partial 'Cache hit at all level'
 
+  unstub cache_dummy
+}
+
+@test 'Existing lower level restore works' {
+  export BUILDKITE_PLUGIN_CACHE_RESTORE=all
+
+  stub cache_dummy \
+    'exists \* : exit 1' \
+    'exists \* : exit 1' \
+    'exists \* : exit 0' \
+    "get \* \* : echo restoring \$2 to \$3"
+
+  run "$PWD/hooks/post-checkout"
+
+  assert_success
+  assert_output --partial 'Cache hit at branch level'
+
   unstub cache_dummy
 }
\ No newline at end of file
diff --git a/tests/post-command-tgz.bats b/tests/post-command-tgz.bats
new file mode 100644
index 0000000..bedf7df
--- /dev/null
+++ b/tests/post-command-tgz.bats
@@ -0,0 +1,88 @@
+#!/usr/bin/env bats
+
+# To debug stubs, uncomment these lines:
+# export CACHE_DUMMY_STUB_DEBUG=/dev/tty
+# export TAR_STUB_DEBUG=/dev/tty
+
+setup() {
+  load "${BATS_PLUGIN_PATH}/load.bash"
+
+  mkdir -p tests/data/my_files
+  echo "all the llamas" > "tests/data/my_files/llamas.txt"
+  echo "no alpacas" > "tests/data/my_files/alpacas.txt"
+
+  export BUILDKITE_PLUGIN_CACHE_BACKEND=dummy
+  export BUILDKITE_PLUGIN_CACHE_COMPRESSION=tgz
+  export BUILDKITE_PLUGIN_CACHE_PATH=tests/data/my_files
+
+  # necessary for key-calculations
+  export BUILDKITE_LABEL="step-label"
+  export BUILDKITE_BRANCH="tests"
+  export BUILDKITE_ORGANIZATION_SLUG="bk-cache-test"
+  export BUILDKITE_PIPELINE_SLUG="cache-pipeline"
+
+  # stubs are the same for every test
+  stub cache_dummy \
+    "save \* \* : echo saving \$3 in \$2"
+
+  stub tar \
+    "czf \* \* : echo compressed \$2 into \$3"
+}
+
+teardown() {
+  rm -rf tests/data
+
+  unstub cache_dummy
+  unstub tar
+}
+
+@test "File-level saving with compression" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=file
+  export BUILDKITE_PLUGIN_CACHE_MANIFEST=tests/data/my_files/llamas.txt
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving file-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with tgz'
+}
+
+@test "Step-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=step
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving step-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with tgz'
+}
+
+@test "Branch-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=branch
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving branch-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with tgz'
+}
+
+@test "Pipeline-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=pipeline
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving pipeline-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with tgz'
+}
+
+@test "All-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=all
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving all-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with tgz'
+}
\ No newline at end of file
diff --git a/tests/post-command-zip.bats b/tests/post-command-zip.bats
new file mode 100644
index 0000000..d8e4390
--- /dev/null
+++ b/tests/post-command-zip.bats
@@ -0,0 +1,88 @@
+#!/usr/bin/env bats
+
+# To debug stubs, uncomment these lines:
+# export CACHE_DUMMY_STUB_DEBUG=/dev/tty
+# export ZIP_STUB_DEBUG=/dev/tty
+
+setup() {
+  load "${BATS_PLUGIN_PATH}/load.bash"
+
+  mkdir -p tests/data/my_files
+  echo "all the llamas" > "tests/data/my_files/llamas.txt"
+  echo "no alpacas" > "tests/data/my_files/alpacas.txt"
+
+  export BUILDKITE_PLUGIN_CACHE_BACKEND=dummy
+  export BUILDKITE_PLUGIN_CACHE_COMPRESSION=zip
+  export BUILDKITE_PLUGIN_CACHE_PATH=tests/data/my_files
+
+  # necessary for key-calculations
+  export BUILDKITE_LABEL="step-label"
+  export BUILDKITE_BRANCH="tests"
+  export BUILDKITE_ORGANIZATION_SLUG="bk-cache-test"
+  export BUILDKITE_PIPELINE_SLUG="cache-pipeline"
+
+  # stubs are the same for every test
+  stub cache_dummy \
+    "save \* \* : echo saving \$3 in \$2"
+
+  stub zip \
+    "echo compressed \${@:2} into \$1"
+}
+
+teardown() {
+  rm -rf tests/data
+
+  unstub cache_dummy
+  unstub zip
+}
+
+@test "File-level saving with compression" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=file
+  export BUILDKITE_PLUGIN_CACHE_MANIFEST=tests/data/my_files/llamas.txt
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving file-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with zip'
+}
+
+@test "Step-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=step
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving step-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with zip'
+}
+
+@test "Branch-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=branch
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving branch-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with zip'
+}
+
+@test "Pipeline-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=pipeline
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving pipeline-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with zip'
+}
+
+@test "All-level saving" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=all
+
+  run "$PWD/hooks/post-command"
+
+  assert_success
+  assert_output --partial 'Saving all-level cache'
+  assert_output --partial 'Compressing tests/data/my_files with zip'
+}
\ No newline at end of file
diff --git a/tests/post-command.bats b/tests/post-command.bats
index 3856881..942cca6 100644
--- a/tests/post-command.bats
+++ b/tests/post-command.bats
@@ -49,6 +49,16 @@ teardown() {
   assert_output --partial 'Invalid cache level'
 }
 
+@test "Invalid compression level fails" {
+  export BUILDKITE_PLUGIN_CACHE_SAVE=all
+  export BUILDKITE_PLUGIN_CACHE_COMPRESSION=invalid
+
+  run "$PWD/hooks/post-command"
+
+  assert_failure
+  assert_output --partial 'Invalid value for compression option'
+}
+
 @test "File-based cache with no manifest fails" {
   export BUILDKITE_PLUGIN_CACHE_SAVE=file
 
diff --git a/tests/shared.bats b/tests/shared.bats
index 2614490..00e6e28 100644
--- a/tests/shared.bats
+++ b/tests/shared.bats
@@ -134,4 +134,39 @@ teardown() {
 
   rm -rf test.folder
   rm -rf FOLDER
+}
+
+@test 'build_key with compression changes' {
+  run build_key file FOLDER
+
+  assert_success
+  EMPTY_KEY="${output}"
+
+  run build_key file FOLDER ''
+  assert_success
+  assert_output "${EMPTY_KEY}"
+
+  run build_key file FOLDER something
+
+  assert_success
+  GENERATED_KEY="${output}"
+
+  run build_key file FOLDER another_thing
+  assert_success
+  refute_output "${GENERATED_KEY}"
+}
+
+@test 'validate_compression works' {
+  run validate_compression none
+
+  assert_success
+
+  run validate_compression tgz
+  assert_success
+
+  run validate_compression zip
+  assert_success
+
+  run validate_compression invalid
+  assert_failure
 }
\ No newline at end of file