diff --git a/api/api_test.go b/api/api_test.go
index f9f3b7b1..afb5e65b 100644
--- a/api/api_test.go
+++ b/api/api_test.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"os"
+	"sort"
 	"strings"
 	"testing"
 
@@ -41,6 +42,17 @@ func createTestConfig() *os.File {
 	jsonString, err := json.Marshal(gin.H{
 		"architectures":         []string{},
 		"enableMetricsEndpoint": true,
+		"S3PublishEndpoints": map[string]map[string]string{
+			"test-s3": {
+				"region": "us-east-1",
+				"bucket": "bucket-s3",
+			},
+		},
+		"GcsPublishEndpoints": map[string]map[string]string{
+			"test-gcs": {
+				"bucket": "bucket-gcs",
+			},
+		},
 	})
 	if err != nil {
 		return nil
@@ -173,3 +185,27 @@ func (s *APISuite) TestTruthy(c *C) {
 	c.Check(truthy(-1), Equals, true)
 	c.Check(truthy(gin.H{}), Equals, true)
 }
+
+func (s *APISuite) TestGetS3Endpoints(c *C) {
+	response, err := s.HTTPRequest("GET", "/api/s3", nil)
+	c.Assert(err, IsNil)
+	c.Check(response.Code, Equals, 200)
+
+	var endpoints []string
+	err = json.Unmarshal(response.Body.Bytes(), &endpoints)
+	c.Assert(err, IsNil)
+	sort.Strings(endpoints)
+	c.Check(endpoints, DeepEquals, []string{"test-s3"})
+}
+
+func (s *APISuite) TestGetGCSEndpoints(c *C) {
+	response, err := s.HTTPRequest("GET", "/api/gcs", nil)
+	c.Assert(err, IsNil)
+	c.Check(response.Code, Equals, 200)
+
+	var endpoints []string
+	err = json.Unmarshal(response.Body.Bytes(), &endpoints)
+	c.Assert(err, IsNil)
+	sort.Strings(endpoints)
+	c.Check(endpoints, DeepEquals, []string{"test-gcs"})
+}
diff --git a/debian/aptly.conf b/debian/aptly.conf
index 54360870..a2c7cf24 100644
--- a/debian/aptly.conf
+++ b/debian/aptly.conf
@@ -256,6 +256,54 @@ s3_publish_endpoints:
     #     # Enables detailed request/response dump for each S3 operation
     #     debug: false
 
+# GCS Endpoint Support
+#
+# aptly can be configured to publish repositories directly to Google Cloud
+# Storage. First, publishing endpoints should be described in the aptly
+# configuration file. Each endpoint has a name and associated settings.
+#
+# In order to publish to GCS, specify endpoint as `gcs:endpoint-name:` before
+# publishing prefix on the command line, e.g.:
+#
+#   `aptly publish snapshot wheezy-main gcs:test:`
+#
+gcs_publish_endpoints:
+    # # Endpoint Name
+    # test:
+    #     # Bucket name
+    #     bucket: test-bucket
+    #     # Prefix (optional)
+    #     # publishing under specified prefix in the bucket, defaults to
+    #     # no prefix (bucket root)
+    #     prefix: ""
+    #     # Credentials File (optional)
+    #     # Path to a service account credentials JSON file
+    #     credentials_file: ""
+    #     # Service Account JSON (optional)
+    #     # Inline service account credentials JSON payload
+    #     service_account_json: ""
+    #     # Project (optional)
+    #     # Quota project used for GCS requests
+    #     project: ""
+    #     # Default ACLs (optional)
+    #     # assign ACL to published files:
+    #     # * private     (default)
+    #     # * public-read (public repository)
+    #     # * none        (don't set ACL)
+    #     acl: private
+    #     # Storage Class (optional)
+    #     # GCS storage class, e.g. `STANDARD`
+    #     storage_class: STANDARD
+    #     # Encryption Key (optional)
+    #     # Customer-supplied encryption key (32-byte AES-256 key)
+    #     encryption_key: ""
+    #     # Disable MultiDel (optional)
+    #     # Kept for parity with S3 settings; GCS deletes are one-by-one
+    #     disable_multidel: false
+    #     # Debug (optional)
+    #     # Enables detailed logs for each GCS operation
+    #     debug: false
+
 # Swift Endpoint Support
 #
 # aptly can publish a repository directly to OpenStack Swift.
diff --git a/gcs/gcs_test.go b/gcs/gcs_test.go
new file mode 100644
index 00000000..b31ecfbe
--- /dev/null
+++ b/gcs/gcs_test.go
@@ -0,0 +1,12 @@
+package gcs
+
+import (
+	"testing"
+
+	. "gopkg.in/check.v1"
+)
+
+// Launch gocheck tests.
+func Test(t *testing.T) {
+	TestingT(t)
+}
diff --git a/gcs/public_test.go b/gcs/public_test.go
new file mode 100644
index 00000000..4cf3d83f
--- /dev/null
+++ b/gcs/public_test.go
@@ -0,0 +1,75 @@
+package gcs
+
+import (
+	"path/filepath"
+
+	"github.com/aptly-dev/aptly/utils"
+	. "gopkg.in/check.v1"
+)
+
+type PublishedStorageSuite struct{}
+
+var _ = Suite(&PublishedStorageSuite{})
+
+func (s *PublishedStorageSuite) TestString(c *C) {
+	storage := &PublishedStorage{bucketName: "bucket-1", prefix: "prefix/a"}
+	c.Check(storage.String(), Equals, "GCS: bucket-1/prefix/a")
+}
+
+func (s *PublishedStorageSuite) TestObjectPath(c *C) {
+	storage := &PublishedStorage{prefix: "root"}
+	c.Check(storage.objectPath("dists/stable/Release"), Equals, filepath.Join("root", "dists/stable/Release"))
+}
+
+func (s *PublishedStorageSuite) TestApplyACLNoOpModes(c *C) {
+	for _, acl := range []string{"", "none", "private"} {
+		storage := &PublishedStorage{acl: acl}
+		err := storage.applyACL(nil)
+		c.Check(err, IsNil)
+	}
+}
+
+func (s *PublishedStorageSuite) TestApplyACLUnsupported(c *C) {
+	storage := &PublishedStorage{acl: "bucket-owner-full-control"}
+	err := storage.applyACL(nil)
+	c.Assert(err, NotNil)
+	c.Check(err, ErrorMatches, "unsupported GCS ACL value: bucket-owner-full-control")
+}
+
+func (s *PublishedStorageSuite) TestLinkFromPoolMissingMD5(c *C) {
+	publishedPrefix := "repo"
+	publishedRelPath := "pool/main/a/aptly"
+	fileName := "pkg.deb"
+	relPath := filepath.Join(filepath.Join(publishedPrefix, publishedRelPath), fileName)
+
+	storage := &PublishedStorage{pathCache: map[string]string{relPath: "0123456789abcdef0123456789abcdef"}}
+
+	err := storage.LinkFromPool(publishedPrefix, publishedRelPath, fileName, nil, "", utils.ChecksumInfo{}, false)
+	c.Assert(err, NotNil)
+	c.Check(err, ErrorMatches, "unable to compare object, MD5 checksum missing")
+}
+
+func (s *PublishedStorageSuite) TestLinkFromPoolDifferentMD5NoForce(c *C) {
+	publishedPrefix := "repo"
+	publishedRelPath := "pool/main/a/aptly"
+	fileName := "pkg.deb"
+	relPath := filepath.Join(filepath.Join(publishedPrefix, publishedRelPath), fileName)
+
+	storage := &PublishedStorage{pathCache: map[string]string{relPath: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}}
+
+	err := storage.LinkFromPool(publishedPrefix, publishedRelPath, fileName, nil, "", utils.ChecksumInfo{MD5: "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"}, false)
+	c.Assert(err, NotNil)
+	c.Check(err, ErrorMatches, ".*file already exists and is different.*")
+}
+
+func (s *PublishedStorageSuite) TestLinkFromPoolSameMD5NoUpload(c *C) {
+	publishedPrefix := "repo"
+	publishedRelPath := "pool/main/a/aptly"
+	fileName := "pkg.deb"
+	relPath := filepath.Join(filepath.Join(publishedPrefix, publishedRelPath), fileName)
+
+	storage := &PublishedStorage{pathCache: map[string]string{relPath: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}}
+
+	err := storage.LinkFromPool(publishedPrefix, publishedRelPath, fileName, nil, "", utils.ChecksumInfo{MD5: "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"}, false)
+	c.Check(err, IsNil)
+}
diff --git a/man/aptly.1 b/man/aptly.1
index 8939dc5f..67351d7a 100644
--- a/man/aptly.1
+++ b/man/aptly.1
@@ -307,6 +307,66 @@ The legacy json configuration is still supported (and also supports comments):
     // }
   },
 
+  // GCS Endpoint Support
+  //
+  // aptly can be configured to publish repositories directly to Google Cloud
+  // Storage\. First, publishing endpoints should be described in the aptly
+  // configuration file\. Each endpoint has a name and associated settings\.
+  //
+  // In order to publish to GCS, specify endpoint as `gcs:endpoint\-name:` before
+  // publishing prefix on the command line, e\.g\.:
+  //
+  //   `aptly publish snapshot wheezy\-main gcs:test:`
+  //
+  "GcsPublishEndpoints": {
+    // // Endpoint Name
+    // "test": {
+
+    //    // Bucket name
+    //    "bucket": "test\-bucket",
+
+    //    // Prefix (optional)
+    //    // publishing under specified prefix in the bucket, defaults to
+    //    // no prefix (bucket root)
+    //    "prefix": "",
+
+    //    // Credentials file (optional)
+    //    // Path to a service account credentials JSON file\. If omitted,
+    //    // Application Default Credentials are used\.
+    //    "credentialsFile": "",
+
+    //    // Service Account JSON (optional)
+    //    // Inline service account credentials JSON content\.
+    //    "serviceAccountJSON": "",
+
+    //    // Project (optional)
+    //    // Quota project to bill requests to\.
+    //    "project": "",
+
+    //    // Default ACLs (optional)
+    //    // assign ACL to published files\. Useful values: `private` (default),
+    //    // `public\-read` (public repository), or `none` (don't set ACL)\.
+    //    "acl": "private",
+
+    //    // Storage Class (optional)
+    //    // GCS storage class, e\.g\. `STANDARD`\.
+    //    "storageClass": "STANDARD",
+
+    //    // Encryption Key (optional)
+    //    // Customer-supplied encryption key (32-byte AES-256 key) for object operations\.
+    //    "encryptionKey": "",
+
+    //    // Disable MultiDel (optional)
+    //    // Kept for parity with S3 settings\.
+    //    // GCS deletes are currently performed one object at a time\.
+    //    "disableMultiDel": false,
+
+    //    // Debug (optional)
+    //    // Enables detailed GCS operation logs
+    //    "debug": false
+    // }
+  },
+
   // Swift Endpoint Support
   //
   // aptly could be configured to publish repository directly to OpenStack Swift\. First,
diff --git a/man/aptly.1.ronn.tmpl b/man/aptly.1.ronn.tmpl
index 708fdbb6..04364310 100644
--- a/man/aptly.1.ronn.tmpl
+++ b/man/aptly.1.ronn.tmpl
@@ -296,6 +296,66 @@ The legacy json configuration is still supported (and also supports comments):
         // }
       },
 
+      // GCS Endpoint Support
+      //
+      // aptly can be configured to publish repositories directly to Google Cloud
+      // Storage. First, publishing endpoints should be described in the aptly
+      // configuration file. Each endpoint has a name and associated settings.
+      //
+      // In order to publish to GCS, specify endpoint as `gcs:endpoint-name:` before
+      // publishing prefix on the command line, e.g.:
+      //
+      //   `aptly publish snapshot wheezy-main gcs:test:`
+      //
+      "GcsPublishEndpoints": {
+        // // Endpoint Name
+        // "test": {
+
+        //    // Bucket name
+        //    "bucket": "test-bucket",
+
+        //    // Prefix (optional)
+        //    // publishing under specified prefix in the bucket, defaults to
+        //    // no prefix (bucket root)
+        //    "prefix": "",
+
+        //    // Credentials file (optional)
+        //    // Path to a service account credentials JSON file. If omitted,
+        //    // Application Default Credentials are used.
+        //    "credentialsFile": "",
+
+        //    // Service Account JSON (optional)
+        //    // Inline service account credentials JSON content.
+        //    "serviceAccountJSON": "",
+
+        //    // Project (optional)
+        //    // Quota project to bill requests to.
+        //    "project": "",
+
+        //    // Default ACLs (optional)
+        //    // assign ACL to published files. Useful values: `private` (default),
+        //    // `public-read` (public repository), or `none` (don't set ACL).
+        //    "acl": "private",
+
+        //    // Storage Class (optional)
+        //    // GCS storage class, e.g. `STANDARD`.
+        //    "storageClass": "STANDARD",
+
+        //    // Encryption Key (optional)
+        //    // Customer-supplied encryption key (32-byte AES-256 key) for object operations.
+        //    "encryptionKey": "",
+
+        //    // Disable MultiDel (optional)
+        //    // Kept for parity with S3 settings.
+        //    // GCS deletes are currently performed one object at a time.
+        //    "disableMultiDel": false,
+
+        //    // Debug (optional)
+        //    // Enables detailed GCS operation logs
+        //    "debug": false
+        // }
+      },
+
       // Swift Endpoint Support
       //
       // aptly could be configured to publish repository directly to OpenStack Swift. First,
diff --git a/system/gcs_lib.py b/system/gcs_lib.py
new file mode 100644
index 00000000..9cc4c5c0
--- /dev/null
+++ b/system/gcs_lib.py
@@ -0,0 +1,101 @@
+from lib import BaseTest
+import os
+import uuid
+
+try:
+    from google.cloud import storage
+
+    gcs_project = os.environ.get('GCS_PROJECT')
+
+    if gcs_project:
+        gcs_client = storage.Client(project=gcs_project)
+    else:
+        print('GCS tests disabled: GCS_PROJECT is not set')
+        gcs_client = None
+except ImportError as e:
+    print("GCS tests disabled: can't import google.cloud.storage", e)
+    gcs_client = None
+except Exception as e:
+    print('GCS tests disabled: unable to initialize GCS client', e)
+    gcs_client = None
+
+
+class GCSTest(BaseTest):
+    """
+    BaseTest + support for GCS
+    """
+
+    gcsOverrides = {}
+
+    def __init__(self) -> None:
+        super(GCSTest, self).__init__()
+        self.bucket_name = None
+        self.bucket = None
+        self.bucket_contents = None
+
+    def fixture_available(self):
+        return super(GCSTest, self).fixture_available() and gcs_client is not None
+
+    def prepare(self):
+        # GCS bucket names must be globally unique and lower-case.
+        self.bucket_name = 'aptly-sys-test-' + str(uuid.uuid4()).replace('_', '-').lower()
+        self.bucket = gcs_client.create_bucket(self.bucket_name)
+
+        self.configOverride = {
+            'GcsPublishEndpoints': {
+                'test1': {
+                    'bucket': self.bucket_name,
+                    'project': gcs_project,
+                },
+            },
+        }
+
+        self.configOverride['GcsPublishEndpoints']['test1'].update(**self.gcsOverrides)
+
+        super(GCSTest, self).prepare()
+
+    def shutdown(self):
+        if self.bucket is not None:
+            for blob in self.bucket.list_blobs():
+                blob.delete()
+            self.bucket.delete(force=True)
+
+        super(GCSTest, self).shutdown()
+
+    def _normalize_path(self, path):
+        if path.startswith('public/'):
+            return path[7:]
+        return path
+
+    def check_path(self, path):
+        if self.bucket_contents is None:
+            self.bucket_contents = [blob.name for blob in self.bucket.list_blobs()]
+
+        path = self._normalize_path(path)
+
+        if path in self.bucket_contents:
+            return True
+
+        if not path.endswith('/'):
+            path = path + '/'
+
+        for item in self.bucket_contents:
+            if item.startswith(path):
+                return True
+
+        return False
+
+    def check_exists(self, path):
+        if not self.check_path(path):
+            raise Exception("path %s doesn't exist" % (path, ))
+
+    def check_not_exists(self, path):
+        if self.check_path(path):
+            raise Exception("path %s exists" % (path, ))
+
+    def read_file(self, path, mode=''):
+        assert not mode
+
+        path = self._normalize_path(path)
+        blob = self.bucket.blob(path)
+        return blob.download_as_text()
diff --git a/system/requirements.txt b/system/requirements.txt
index a00a2a65..40ea29af 100644
--- a/system/requirements.txt
+++ b/system/requirements.txt
@@ -1,4 +1,5 @@
 azure-storage-blob
+google-cloud-storage
 boto
 requests==2.33.0
 requests-unixsocket
diff --git a/system/t06_publish/gcs.py b/system/t06_publish/gcs.py
new file mode 100644
index 00000000..d60c5553
--- /dev/null
+++ b/system/t06_publish/gcs.py
@@ -0,0 +1,116 @@
+from gcs_lib import GCSTest
+
+
+def strip_processor(output):
+    return '\n'.join(
+        [
+            l
+            for l in output.split('\n')
+            if not l.startswith(' ') and not l.startswith('Date:')
+        ]
+    )
+
+
+class GCSPublish1Test(GCSTest):
+    """
+    publish to GCS: from repo
+    """
+
+    fixtureCmds = [
+        'aptly repo create -distribution=maverick local-repo',
+        'aptly repo add local-repo ${files}',
+        'aptly repo remove local-repo libboost-program-options-dev_1.62.0.1_i386',
+    ]
+    runCmd = 'aptly publish repo -keyring=${files}/aptly.pub -secret-keyring=${files}/aptly.sec local-repo gcs:test1:'
+
+    def check(self):
+        self.check_exists('public/dists/maverick/InRelease')
+        self.check_exists('public/dists/maverick/Release')
+        self.check_exists('public/dists/maverick/Release.gpg')
+
+        self.check_exists('public/dists/maverick/main/binary-i386/Packages')
+        self.check_exists('public/dists/maverick/main/binary-i386/Packages.gz')
+        self.check_exists('public/dists/maverick/main/binary-i386/Packages.bz2')
+        self.check_exists('public/dists/maverick/main/source/Sources')
+        self.check_exists('public/dists/maverick/main/source/Sources.gz')
+        self.check_exists('public/dists/maverick/main/source/Sources.bz2')
+
+        self.check_exists('public/pool/main/p/pyspi/pyspi_0.6.1-1.3.dsc')
+        self.check_exists('public/pool/main/p/pyspi/pyspi_0.6.1-1.3.diff.gz')
+        self.check_exists('public/pool/main/p/pyspi/pyspi_0.6.1.orig.tar.gz')
+        self.check_exists('public/pool/main/p/pyspi/pyspi-0.6.1-1.3.stripped.dsc')
+        self.check_exists(
+            'public/pool/main/b/boost-defaults/libboost-program-options-dev_1.49.0.1_i386.deb'
+        )
+
+        # verify contents except sums/date chunks
+        self.check_file_contents(
+            'public/dists/maverick/Release', 'release', match_prepare=strip_processor
+        )
+        self.check_file_contents(
+            'public/dists/maverick/main/source/Sources',
+            'sources',
+            match_prepare=lambda s: '\n'.join(sorted(s.split('\n'))),
+        )
+        self.check_file_contents(
+            'public/dists/maverick/main/binary-i386/Packages',
+            'binary',
+            match_prepare=lambda s: '\n'.join(sorted(s.split('\n'))),
+        )
+
+
+class GCSPublish2Test(GCSTest):
+    """
+    publish to GCS: update after removing package from repo
+    """
+
+    fixtureCmds = [
+        'aptly repo create -distribution=maverick local-repo',
+        'aptly repo add local-repo ${files}/',
+        'aptly repo remove local-repo libboost-program-options-dev_1.62.0.1_i386',
+        'aptly publish repo -keyring=${files}/aptly.pub -secret-keyring=${files}/aptly.sec local-repo gcs:test1:',
+        'aptly repo remove local-repo pyspi',
+    ]
+    runCmd = 'aptly publish update -keyring=${files}/aptly.pub -secret-keyring=${files}/aptly.sec maverick gcs:test1:'
+
+    def check(self):
+        self.check_exists('public/dists/maverick/InRelease')
+        self.check_exists('public/dists/maverick/Release')
+        self.check_exists('public/dists/maverick/Release.gpg')
+
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi_0.6.1-1.3.dsc')
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi_0.6.1-1.3.diff.gz')
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi_0.6.1.orig.tar.gz')
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi-0.6.1-1.3.stripped.dsc')
+        self.check_exists(
+            'public/pool/main/b/boost-defaults/libboost-program-options-dev_1.49.0.1_i386.deb'
+        )
+
+
+class GCSPublish3Test(GCSTest):
+    """
+    publish to GCS: publish drop performs cleanup
+    """
+
+    fixtureCmds = [
+        'aptly repo create local1',
+        'aptly repo create local2',
+        'aptly repo add local1 ${files}/libboost-program-options-dev_1.49.0.1_i386.deb',
+        'aptly repo add local2 ${files}',
+        'aptly publish repo -keyring=${files}/aptly.pub -secret-keyring=${files}/aptly.sec -distribution=sq1 local1 gcs:test1:',
+        'aptly publish repo -keyring=${files}/aptly.pub -secret-keyring=${files}/aptly.sec -distribution=sq2 local2 gcs:test1:',
+    ]
+    runCmd = 'aptly publish drop sq2 gcs:test1:'
+
+    def check(self):
+        self.check_exists('public/dists/sq1')
+        self.check_not_exists('public/dists/sq2')
+        self.check_exists('public/pool/main/')
+
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi_0.6.1-1.3.dsc')
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi_0.6.1-1.3.diff.gz')
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi_0.6.1.orig.tar.gz')
+        self.check_not_exists('public/pool/main/p/pyspi/pyspi-0.6.1-1.3.stripped.dsc')
+        self.check_exists(
+            'public/pool/main/b/boost-defaults/libboost-program-options-dev_1.49.0.1_i386.deb'
+        )