diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46e078686..a436dd1f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+# 1.6.6
+- Read version from package.json to update agentVersion variable.
+
 # 1.6.5
 - Added fragment as user configurable. Support for case when user wants to redact sensitive information in url fragment.
 
diff --git a/lib/commonBeaconProperties.js b/lib/commonBeaconProperties.js
index 371182a42..609bb0a2a 100644
--- a/lib/commonBeaconProperties.js
+++ b/lib/commonBeaconProperties.js
@@ -31,6 +31,7 @@ export function addCommonBeaconProperties(beacon: Beacon) {
   beacon['sid'] = vars.sessionId;
   beacon['ww'] = win.innerWidth;
   beacon['wh'] = win.innerHeight;
+  beacon['agv'] = vars.agentVersion;
   // Google Closure compiler is not yet aware of these globals. Make sure it doesn't
   // mangle them.
   if (nav['connection'] && nav['connection']['effectiveType']) {
diff --git a/lib/types.js b/lib/types.js
index 01fa7c2bf..a6c4a1261 100644
--- a/lib/types.js
+++ b/lib/types.js
@@ -73,7 +73,10 @@ export interface Beacon {
 
   // Meta data
   // m_abc: string,
-  [key: string]: ?number|?string
+  [key: string]: ?number|?string,
+
+  // Agent Version
+  agv: ?string
 }
 
 export interface BeaconWithResourceTiming extends Beacon {
diff --git a/lib/vars.js b/lib/vars.js
index 4a8d9b0d8..e408420f5 100644
--- a/lib/vars.js
+++ b/lib/vars.js
@@ -294,6 +294,9 @@ const defaultVars: {
   // eum('reportingBackends', [{reportingUrl: '//eum.example.com', key: 'key'}]);
   reportingBackends: ReportingBackend[],
 
+  //The version of Weasel agent.
+  agentVersion: ?string,
+
   // Whether or not weasel should generate dedicated custom events on webvital metrics
   // these custom events is more reliable than webvitals in PageLoad beacon, as we
   // will not wait for so long in PageLoad beacon, with custom events, these metrics
@@ -354,6 +357,8 @@ const defaultVars: {
   fragment: [],
   headersToCapture: [],
   reportingBackends: [],
+  agentVersion: '0.0.0',  
+  //0.0.0 will be replaced with version from package.json
   webvitalsInCustomEvent: false
 };
 
diff --git a/package.json b/package.json
index 24007e956..61faf3d61 100644
--- a/package.json
+++ b/package.json
@@ -1,5 +1,5 @@
 {
-  "version": "1.6.5",
+  "version": "1.6.6",
   "name": "@instana/weasel",
   "description": "Collect end-user data",
   "main": "lib/index.js",