diff --git a/keyserver/src/endpoints.js b/keyserver/src/endpoints.js
--- a/keyserver/src/endpoints.js
+++ b/keyserver/src/endpoints.js
@@ -76,6 +76,7 @@
   updateUserAvatarResponder,
 } from './responders/user-responders.js';
 import { codeVerificationResponder } from './responders/verification-responders.js';
+import { versionResponder } from './responders/version-responders.js';
 import {
   uploadMediaMetadataResponder,
   uploadDeletionResponder,
@@ -310,6 +311,10 @@
     responder: getOlmSessionInitializationDataResponder,
     requiredPolicies: [],
   },
+  version: {
+    responder: versionResponder,
+    requiredPolicies: [],
+  },
 };
 
 export { jsonEndpoints };
diff --git a/keyserver/src/responders/version-responders.js b/keyserver/src/responders/version-responders.js
new file mode 100644
--- /dev/null
+++ b/keyserver/src/responders/version-responders.js
@@ -0,0 +1,24 @@
+// @flow
+
+import t, { type TInterface } from 'tcomb';
+
+import { webAndKeyserverCodeVersion } from 'lib/facts/version.js';
+import type { VersionResponse } from 'lib/types/device-types.js';
+import { tShape } from 'lib/utils/validation-utils.js';
+
+import type { Viewer } from '../session/viewer.js';
+import { validateOutput } from '../utils/validation-utils.js';
+
+const versionResponseValidator: TInterface<VersionResponse> =
+  tShape<VersionResponse>({ codeVersion: t.Number });
+
+async function versionResponder(viewer: Viewer): Promise<VersionResponse> {
+  const response = { codeVersion: webAndKeyserverCodeVersion };
+  return validateOutput(
+    viewer.platformDetails,
+    versionResponseValidator,
+    response,
+  );
+}
+
+export { versionResponder };
diff --git a/lib/types/device-types.js b/lib/types/device-types.js
--- a/lib/types/device-types.js
+++ b/lib/types/device-types.js
@@ -40,3 +40,7 @@
   +codeVersion?: number,
   +stateVersion?: number,
 };
+
+export type VersionResponse = {
+  +codeVersion: number,
+};
diff --git a/lib/types/endpoints.js b/lib/types/endpoints.js
--- a/lib/types/endpoints.js
+++ b/lib/types/endpoints.js
@@ -95,6 +95,7 @@
   UPLOAD_MEDIA_METADATA: 'upload_media_metadata',
   SEARCH_MESSAGES: 'search_messages',
   GET_OLM_SESSION_INITIALIZATION_DATA: 'get_olm_session_initialization_data',
+  VERSION: 'version',
 });
 type SocketPreferredEndpoint = $Values<typeof socketPreferredEndpoints>;