feat(telemetry): recording a sanitized version of the client name (#2757)

src/telemetry/ClearcutLogger.ts

@@ -16,10 +16,12 @@ import {
   bucketizeDaysSince,
   bucketizeLatency,
   buildContext,
+  sanitizeClientName,
   sanitizeParams,
   stripUnderscoreBeforeNumber,
 } from './transformation.js';
 import {
+  type ChromeDevToolsMcpExtension,
   McpClient,
   type FlagUsage,
   WatchdogMessageType,
@@ -88,6 +90,7 @@ export class ClearcutLogger {
   #persistence: Persistence;
   #watchdog: WatchdogClient;
   #mcpClient: McpClient;
+  #rawClientName?: string;
   #state?: LocalState;
 
   static initialize(options: ClearcutLoggerOptions): ClearcutLogger {
@@ -157,9 +160,28 @@ export class ClearcutLogger {
       this.#mcpClient = McpClient.MCP_CLIENT_HERMES;
     } else {
       this.#mcpClient = McpClient.MCP_CLIENT_OTHER;
+      this.#rawClientName = sanitizeClientName(clientName);
     }
   }
 
+  #addMcpClient(
+    payload: ChromeDevToolsMcpExtension,
+  ): ChromeDevToolsMcpExtension {
+    const ext: ChromeDevToolsMcpExtension = {
+      ...payload,
+      mcp_client: this.#mcpClient,
+    };
+    if (
+      this.#mcpClient === McpClient.MCP_CLIENT_OTHER &&
+      this.#rawClientName !== undefined
+    ) {
+      ext.raw_mcp_client_info = {
+        raw_client_name: this.#rawClientName,
+      };
+    }
+    return ext;
+  }
+
   async logToolInvocation(args: {
     toolName: string;
     params: ShapeOutput<zod.ZodRawShape>;
@@ -194,22 +216,20 @@ export class ClearcutLogger {
 
     this.#watchdog.send({
       type: WatchdogMessageType.LOG_EVENT,
-      payload: {
-        mcp_client: this.#mcpClient,
+      payload: this.#addMcpClient({
         tool_invocation: tool_invocation,
-      },
+      }),
     });
   }
 
   async logServerStart(flagUsage: FlagUsage): Promise<void> {
     this.#watchdog.send({
       type: WatchdogMessageType.LOG_EVENT,
-      payload: {
-        mcp_client: this.#mcpClient,
+      payload: this.#addMcpClient({
         server_start: {
           flag_usage: flagUsage,
         },
-      },
+      }),
     });
   }
 
@@ -222,12 +242,11 @@ export class ClearcutLogger {
 
         this.#watchdog.send({
           type: WatchdogMessageType.LOG_EVENT,
-          payload: {
-            mcp_client: this.#mcpClient,
+          payload: this.#addMcpClient({
             daily_active: {
               days_since_last_active: bucketizeDaysSince(daysSince),
             },
-          },
+          }),
         });
 
         this.#state.lastActive = new Date().toISOString();
@@ -244,15 +263,14 @@ export class ClearcutLogger {
   }): Promise<void> {
     this.#watchdog.send({
       type: WatchdogMessageType.LOG_EVENT,
-      payload: {
-        mcp_client: this.#mcpClient,
+      payload: this.#addMcpClient({
         server_error: {
           tool_name: args.toolName
             ? stripUnderscoreBeforeNumber(args.toolName)
             : '',
           error_code: args.errorCode,
         },
-      },
+      }),
     });
   }
 
@@ -282,12 +300,11 @@ export class ClearcutLogger {
 
     this.#watchdog.send({
       type: WatchdogMessageType.LOG_EVENT,
-      payload: {
-        mcp_client: this.#mcpClient,
+      payload: this.#addMcpClient({
         tool_active: {
           days_since_last_tool_call: bucketizeDaysSince(daysSinceToolCall),
         },
-      },
+      }),
     });
 
     this.#state.lastToolCall = now.toISOString();

src/telemetry/transformation.ts

@@ -27,6 +27,21 @@ export function bucketizeDaysSince(days: number): number {
   return Math.min(days, MAX_ACTIVE_DAYS);
 }
 
+export const REDACTED_CLIENT_NAME = '<redacted>';
+const VALID_CLIENT_NAME_REGEX = /^[a-zA-Z0-9_-]+$/;
+const MAX_CLIENT_NAME_LENGTH = 32;
+
+export function sanitizeClientName(clientName: string): string {
+  if (
+    clientName.length > 0 &&
+    clientName.length < MAX_CLIENT_NAME_LENGTH &&
+    VALID_CLIENT_NAME_REGEX.test(clientName)
+  ) {
+    return clientName;
+  }
+  return REDACTED_CLIENT_NAME;
+}
+
 export const PARAM_BLOCKLIST = new Set(['uid', 'reqid', 'msgid']);
 
 const SUPPORTED_ZOD_TYPES = [

src/telemetry/types.ts

@@ -10,6 +10,7 @@ import type {ErrorCode} from './errors.js';
 export interface ChromeDevToolsMcpExtension {
   os_type?: OsType;
   mcp_client?: McpClient;
+  raw_mcp_client_info?: RawMcpClientInfo;
   app_version?: string;
   session_id?: string;
   tool_invocation?: ToolInvocation;
@@ -20,6 +21,10 @@ export interface ChromeDevToolsMcpExtension {
   tool_active?: ToolActive;
 }
 
+export interface RawMcpClientInfo {
+  raw_client_name: string;
+}
+
 export interface ServerError {
   tool_name?: string;
   error_code: ErrorCode;

tests/telemetry/ClearcutLogger.test.ts

@@ -137,11 +137,12 @@ describe('ClearcutLogger', () => {
       {name: 'xai-sdk', expected: 8}, // MCP_CLIENT_GROK
       {name: 'github-copilot-developer', expected: 11}, // MCP_CLIENT_GITHUB_COPILOT
       {name: 'copilot-intellij', expected: 11}, // MCP_CLIENT_GITHUB_COPILOT
-      {name: 'unknown-client', expected: 3}, // MCP_CLIENT_OTHER
+      {name: 'unknown-client', expected: 3, rawName: 'unknown-client'}, // MCP_CLIENT_OTHER
+      {name: 'unknown client', expected: 3, rawName: '<redacted>'}, // MCP_CLIENT_OTHER
       {name: 'hermes-agent/1.0.0', expected: 12}, // MCP_CLIENT_HERMES
     ];
 
-    for (const {name, expected} of clients) {
+    for (const {name, expected, rawName} of clients) {
       it(`maps ${name} client correctly`, async () => {
         const logger = ClearcutLogger.initialize({
           persistence: mockPersistence,
@@ -156,6 +157,9 @@ describe('ClearcutLogger', () => {
           type: WatchdogMessageType.LOG_EVENT,
           payload: {
             mcp_client: expected,
+            ...(rawName
+              ? {raw_mcp_client_info: {raw_client_name: rawName}}
+              : {}),
             server_start: {
               flag_usage: {headless: true},
             },

tests/telemetry/transformation.test.ts

@@ -13,6 +13,7 @@ import {
   buildContext,
   getEnumValues,
   MAX_ACTIVE_DAYS,
+  sanitizeClientName,
   sanitizeParams,
   stripUnderscoreBeforeNumber,
   transformArgName,
@@ -277,3 +278,32 @@ describe('buildContext', () => {
     );
   });
 });
+
+describe('sanitizeClientName', () => {
+  it('returns valid alphanumeric client names with hyphens and underscores as is', () => {
+    const validNames = [
+      'a',
+      'my-custom_client123',
+      'Client_Name-1',
+      'a'.repeat(31),
+    ];
+    for (const name of validNames) {
+      assert.strictEqual(sanitizeClientName(name), name);
+    }
+  });
+
+  it('redacts invalid or overly long client names', () => {
+    const invalidNames = [
+      '',
+      'a'.repeat(32),
+      'a'.repeat(100),
+      'client with spaces',
+      'client/1.0',
+      'client.name',
+      'client@home',
+    ];
+    for (const name of invalidNames) {
+      assert.strictEqual(sanitizeClientName(name), '<redacted>');
+    }
+  });
+});