diff --git a/src/index.ts b/src/index.ts
index 7dabf6766..2689e34a6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -57,6 +57,13 @@ export async function createMcpServer(
     return {};
   });
 
+  server.server.oninitialized = () => {
+    const clientName = server.server.getClientVersion()?.name;
+    if (clientName) {
+      clearcutLogger?.setClientName(clientName);
+    }
+  };
+
   let context: McpContext;
   async function getContext(): Promise<McpContext> {
     const chromeArgs: string[] = (serverArgs.chromeArg ?? []).map(String);
diff --git a/src/telemetry/ClearcutLogger.ts b/src/telemetry/ClearcutLogger.ts
index 7deadbf01..dfb592451 100644
--- a/src/telemetry/ClearcutLogger.ts
+++ b/src/telemetry/ClearcutLogger.ts
@@ -10,7 +10,12 @@ import {logger} from '../logger.js';
 
 import type {LocalState, Persistence} from './persistence.js';
 import {FilePersistence} from './persistence.js';
-import {type FlagUsage, WatchdogMessageType, OsType} from './types.js';
+import {
+  McpClient,
+  type FlagUsage,
+  WatchdogMessageType,
+  OsType,
+} from './types.js';
 import {WatchdogClient} from './WatchdogClient.js';
 
 const MS_PER_DAY = 24 * 60 * 60 * 1000;
@@ -31,6 +36,7 @@ function detectOsType(): OsType {
 export class ClearcutLogger {
   #persistence: Persistence;
   #watchdog: WatchdogClient;
+  #mcpClient: McpClient;
 
   constructor(options: {
     appVersion: string;
@@ -53,6 +59,18 @@ export class ClearcutLogger {
         clearcutForceFlushIntervalMs: options.clearcutForceFlushIntervalMs,
         clearcutIncludePidHeader: options.clearcutIncludePidHeader,
       });
+    this.#mcpClient = McpClient.MCP_CLIENT_UNSPECIFIED;
+  }
+
+  setClientName(clientName: string): void {
+    const lowerName = clientName.toLowerCase();
+    if (lowerName.includes('claude')) {
+      this.#mcpClient = McpClient.MCP_CLIENT_CLAUDE_CODE;
+    } else if (lowerName.includes('gemini')) {
+      this.#mcpClient = McpClient.MCP_CLIENT_GEMINI_CLI;
+    } else {
+      this.#mcpClient = McpClient.MCP_CLIENT_OTHER;
+    }
   }
 
   async logToolInvocation(args: {
@@ -63,6 +81,7 @@ export class ClearcutLogger {
     this.#watchdog.send({
       type: WatchdogMessageType.LOG_EVENT,
       payload: {
+        mcp_client: this.#mcpClient,
         tool_invocation: {
           tool_name: args.toolName,
           success: args.success,
@@ -76,6 +95,7 @@ export class ClearcutLogger {
     this.#watchdog.send({
       type: WatchdogMessageType.LOG_EVENT,
       payload: {
+        mcp_client: this.#mcpClient,
         server_start: {
           flag_usage: flagUsage,
         },
@@ -99,6 +119,7 @@ export class ClearcutLogger {
         this.#watchdog.send({
           type: WatchdogMessageType.LOG_EVENT,
           payload: {
+            mcp_client: this.#mcpClient,
             daily_active: {
               days_since_last_active: daysSince,
             },
diff --git a/src/telemetry/types.ts b/src/telemetry/types.ts
index 24d18b94f..8d8325419 100644
--- a/src/telemetry/types.ts
+++ b/src/telemetry/types.ts
@@ -75,6 +75,7 @@ export enum McpClient {
   MCP_CLIENT_UNSPECIFIED = 0,
   MCP_CLIENT_CLAUDE_CODE = 1,
   MCP_CLIENT_GEMINI_CLI = 2,
+  MCP_CLIENT_OTHER = 3,
 }
 
 // IPC types for messages between the main process and the
diff --git a/tests/telemetry/ClearcutLogger.test.ts b/tests/telemetry/ClearcutLogger.test.ts
index b8b1d1dc7..960689613 100644
--- a/tests/telemetry/ClearcutLogger.test.ts
+++ b/tests/telemetry/ClearcutLogger.test.ts
@@ -54,6 +54,24 @@ describe('ClearcutLogger', () => {
     });
   });
 
+  describe('setClientName', () => {
+    it('appends mapped mcp_client to payload', async () => {
+      const logger = new ClearcutLogger({
+        persistence: mockPersistence,
+        appVersion: '1.0.0',
+        watchdogClient: mockWatchdogClient,
+      });
+
+      logger.setClientName('gemini-cli-mcp-client');
+      await logger.logServerStart({headless: true});
+
+      assert(mockWatchdogClient.send.calledOnce);
+      const msg = mockWatchdogClient.send.firstCall.args[0];
+      assert.strictEqual(msg.type, WatchdogMessageType.LOG_EVENT);
+      assert.strictEqual(msg.payload.mcp_client, 2); // 2 is MCP_CLIENT_GEMINI_CLI
+    });
+  });
+
   describe('logServerStart', () => {
     it('logs flag usage', async () => {
       const logger = new ClearcutLogger({