diff --git a/packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts b/packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts
index 7beacb9b..e42aa677 100644
--- a/packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts
+++ b/packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts
@@ -205,11 +205,16 @@ export class ClearcutLogger {
   }
 
   logStartSessionEvent(event: StartSessionEvent): void {
+    const surface = process.env.SURFACE || 'SURFACE_NOT_SET';
     const data = [
       {
         gemini_cli_key: EventMetadataKey.GEMINI_CLI_START_SESSION_MODEL,
         value: event.model,
       },
+      {
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SESSION_ID,
+        value: this.config?.getSessionId() ?? '',
+      },
       {
         gemini_cli_key:
           EventMetadataKey.GEMINI_CLI_START_SESSION_EMBEDDING_MODEL,
@@ -266,7 +271,12 @@ export class ClearcutLogger {
           EventMetadataKey.GEMINI_CLI_START_SESSION_TELEMETRY_LOG_USER_PROMPTS_ENABLED,
         value: event.telemetry_log_user_prompts_enabled.toString(),
       },
+      {
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SURFACE,
+        value: surface,
+      },
     ];
+
     // Flush start event immediately
     this.enqueueLogEvent(this.createLogEvent(start_session_event_name, data));
     this.flushToClearcut().catch((error) => {
@@ -280,6 +290,10 @@ export class ClearcutLogger {
         gemini_cli_key: EventMetadataKey.GEMINI_CLI_USER_PROMPT_LENGTH,
         value: JSON.stringify(event.prompt_length),
       },
+      {
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SESSION_ID,
+        value: this.config?.getSessionId() ?? '',
+      },
       {
         gemini_cli_key: EventMetadataKey.GEMINI_CLI_PROMPT_ID,
         value: JSON.stringify(event.prompt_id),
@@ -442,6 +456,10 @@ export class ClearcutLogger {
         gemini_cli_key: EventMetadataKey.GEMINI_CLI_AUTH_TYPE,
         value: JSON.stringify(event.auth_type),
       },
+      {
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SESSION_ID,
+        value: this.config?.getSessionId() ?? '',
+      },
     ];
 
     this.enqueueLogEvent(this.createLogEvent(flash_fallback_event_name, data));
@@ -452,6 +470,10 @@ export class ClearcutLogger {
 
   logLoopDetectedEvent(event: LoopDetectedEvent): void {
     const data = [
+      {
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SESSION_ID,
+        value: this.config?.getSessionId() ?? '',
+      },
       {
         gemini_cli_key: EventMetadataKey.GEMINI_CLI_LOOP_DETECTED_TYPE,
         value: JSON.stringify(event.loop_type),
@@ -465,7 +487,7 @@ export class ClearcutLogger {
   logEndSessionEvent(event: EndSessionEvent): void {
     const data = [
       {
-        gemini_cli_key: EventMetadataKey.GEMINI_CLI_END_SESSION_ID,
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SESSION_ID,
         value: event?.session_id?.toString() ?? '',
       },
     ];
diff --git a/packages/core/src/telemetry/clearcut-logger/event-metadata-key.ts b/packages/core/src/telemetry/clearcut-logger/event-metadata-key.ts
index 4a47488a..b34cc6ea 100644
--- a/packages/core/src/telemetry/clearcut-logger/event-metadata-key.ts
+++ b/packages/core/src/telemetry/clearcut-logger/event-metadata-key.ts
@@ -151,6 +151,12 @@ export enum EventMetadataKey {
   // Logs the total number of Google accounts ever used.
   GEMINI_CLI_GOOGLE_ACCOUNTS_COUNT = 37,
 
+  // Logs the Surface from where the Gemini CLI was invoked, eg: VSCode.
+  GEMINI_CLI_SURFACE = 39,
+
+  // Logs the session id
+  GEMINI_CLI_SESSION_ID = 40,
+
   // ==========================================================================
   // Loop Detected Event Keys
   // ===========================================================================