Remove per-call replay recording from execute_playwright_code

Each execute_playwright_code call wrapped the run in replays.start /
replays.stop and validated existing sessions with a browsers.retrieve,
adding three round trips around the one useful call. In a tight agent
loop that latency lands on the critical path every turn.

Drop the replay start/stop and the pre-execute retrieve; execute
surfaces a not-found error on its own. Existing-session calls now make
a single round trip. Video replay is handled separately via managed
replay controls.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dprevoznik

README.md

@@ -20,7 +20,7 @@ The Kernel MCP Server bridges AI assistants (like Claude, Cursor, or other MCP-c
 - 📊 Monitor deployments and track invocations
 - 🔍 Search Kernel documentation and inject context
 - 💻 Execute arbitrary Playwright code against live browsers
-- 🎥 Automatically record video replays of browser automation
+- 🎥 Record video replays of browser automation
 
 **Open-source & fully-managed** — the complete codebase is available here, and we run the production instance so you don't need to deploy anything.
 
@@ -279,7 +279,7 @@ Self-hosted deployments can hide sensitive tool families by setting `KERNEL_MCP_
 
 - `computer_action` - Mouse, keyboard, clipboard, and screenshot controls for browser sessions (click, type, press_key, scroll, move, get_position, read_clipboard, write_clipboard, screenshot).
 - `browser_curl` - Send HTTP requests through an existing browser session's Chrome network stack.
-- `execute_playwright_code` - Execute Playwright/TypeScript code against a browser with automatic video replay and cleanup.
+- `execute_playwright_code` - Execute Playwright/TypeScript code against a browser, with automatic cleanup of browsers it creates.
 - `exec_command` - Run shell commands inside a browser VM. Returns decoded stdout/stderr.
 - `search_docs` - Search Kernel platform documentation and guides.
 
@@ -322,7 +322,7 @@ Assistant: I'll execute your web-scraper action with reddit.com as the target.
 Human: Go to example.com and get me the page title
 Assistant: I'll execute Playwright code to navigate to the site and retrieve the title.
 [Uses execute_playwright_code tool with code: "await page.goto('https://example.com'); return await page.title();"]
-Returns: { success: true, result: "Example Domain", replay_url: "https://..." }
+Returns: { success: true, result: "Example Domain" }
 ```
 
 ### Set up browser profiles for authentication

src/lib/mcp/tools/playwright.ts

@@ -6,7 +6,7 @@ export function registerPlaywrightTool(server: McpServer) {
   // execute_playwright_code -- Run Playwright/TypeScript code against a browser
   server.tool(
     "execute_playwright_code",
-    'Execute Playwright/TypeScript automation code against a Kernel browser session. If session_id is provided, uses that existing browser; otherwise creates a new one. Returns the result with a video replay URL. Auto-cleans up browsers it creates. Use computer_action with action "screenshot" instead of page.screenshot() in code.',
+    'Execute Playwright/TypeScript automation code against a Kernel browser session. If session_id is provided, uses that existing browser; otherwise creates a new one. Auto-cleans up browsers it creates. Use computer_action with action "screenshot" instead of page.screenshot() in code.',
     {
       code: z
         .string()
@@ -30,49 +30,27 @@ export function registerPlaywrightTool(server: McpServer) {
     async ({ code, session_id }, extra) => {
       if (!extra.authInfo) throw new Error("Authentication required");
       const client = createKernelClient(extra.authInfo.token);
-      let kernelBrowser;
-      let replay;
       const shouldCleanup = !session_id;
+      let activeSessionId = session_id;
 
       try {
         if (!code || typeof code !== "string")
           throw new Error("code is required and must be a string");
 
-        if (session_id) {
-          kernelBrowser = await client.browsers.retrieve(session_id);
-          if (!kernelBrowser)
-            throw new Error(`Browser session "${session_id}" not found`);
-        } else {
-          kernelBrowser = await client.browsers.create({ stealth: true });
-          if (!kernelBrowser?.session_id)
+        if (!activeSessionId) {
+          const created = await client.browsers.create({ stealth: true });
+          if (!created?.session_id)
             throw new Error("Failed to create browser session");
-        }
-
-        try {
-          replay = await client.browsers.replays.start(
-            kernelBrowser.session_id,
-          );
-        } catch {
-          replay = null;
+          activeSessionId = created.session_id;
         }
 
         const response = await client.browsers.playwright.execute(
-          kernelBrowser.session_id,
+          activeSessionId,
           { code },
         );
 
-        let replayUrl = null;
-        if (replay && kernelBrowser?.session_id) {
-          try {
-            await client.browsers.replays.stop(replay.replay_id, {
-              id: kernelBrowser.session_id,
-            });
-            replayUrl = replay.replay_view_url;
-          } catch {}
-        }
-
-        if (shouldCleanup && kernelBrowser?.session_id) {
-          await client.browsers.deleteByID(kernelBrowser.session_id);
+        if (shouldCleanup) {
+          await client.browsers.deleteByID(activeSessionId);
         }
 
         return {
@@ -86,7 +64,6 @@ export function registerPlaywrightTool(server: McpServer) {
                   error: response.error,
                   stdout: response.stdout,
                   stderr: response.stderr,
-                  replay_url: replayUrl,
                 },
                 null,
                 2,
@@ -95,18 +72,9 @@ export function registerPlaywrightTool(server: McpServer) {
           ],
         };
       } catch (error) {
-        let replayUrl = null;
-        if (replay && kernelBrowser?.session_id) {
-          try {
-            await client.browsers.replays.stop(replay.replay_id, {
-              id: kernelBrowser.session_id,
-            });
-            replayUrl = replay.replay_view_url;
-          } catch {}
-        }
         try {
-          if (shouldCleanup && kernelBrowser?.session_id)
-            await client.browsers.deleteByID(kernelBrowser.session_id);
+          if (shouldCleanup && activeSessionId)
+            await client.browsers.deleteByID(activeSessionId);
         } catch {}
 
         return {
@@ -117,7 +85,6 @@ export function registerPlaywrightTool(server: McpServer) {
                 {
                   success: false,
                   error: error instanceof Error ? error.message : String(error),
-                  replay_url: replayUrl,
                 },
                 null,
                 2,