removed relayConnection.ts. added diff for ai snapshot. use search param

playwriter/package.json

@@ -40,6 +40,7 @@
     "@modelcontextprotocol/sdk": "^1.21.1",
     "chalk": "^5.6.2",
     "devtools-protocol": "^0.0.1543509",
+    "diff": "^8.0.2",
     "hono": "^4.10.6",
     "playwright-core": "^1.56.1",
     "string-dedent": "^3.0.2",

playwriter/src/mcp.test.ts

@@ -226,9 +226,9 @@ describe('MCP Server Tests', () => {
             const tabs = await chrome.tabs.query({})
             const testTab = tabs.find((t: any) => t.url?.includes('mcp-test'))
             return {
-                connected: !!testTab && !!testTab.id && state.connectedTabs.has(testTab.id),
+                connected: !!testTab && !!testTab.id && state.tabs.has(testTab.id),
                 tabId: testTab?.id,
-                tabInfo: testTab?.id ? state.connectedTabs.get(testTab.id) : null,
+                tabInfo: testTab?.id ? state.tabs.get(testTab.id) : null,
                 connectionState: state.connectionState
             }
         })
@@ -581,8 +581,8 @@ describe('MCP Server Tests', () => {
              const tabA = tabs.find((t: any) => t.url?.includes('tab-a'))
              const tabB = tabs.find((t: any) => t.url?.includes('tab-b'))
              return {
-                 idA: state.connectedTabs.get(tabA?.id ?? -1)?.targetId,
-                 idB: state.connectedTabs.get(tabB?.id ?? -1)?.targetId
+                 idA: state.tabs.get(tabA?.id ?? -1)?.targetId,
+                 idB: state.tabs.get(tabB?.id ?? -1)?.targetId
              }
         })
 
@@ -667,8 +667,8 @@ describe('MCP Server Tests', () => {
              const tabA = tabs.find((t: any) => t.url?.includes('tab-a'))
              const tabB = tabs.find((t: any) => t.url?.includes('tab-b'))
              return {
-                 idA: state.connectedTabs.get(tabA?.id ?? -1)?.targetId,
-                 idB: state.connectedTabs.get(tabB?.id ?? -1)?.targetId
+                 idA: state.tabs.get(tabA?.id ?? -1)?.targetId,
+                 idB: state.tabs.get(tabB?.id ?? -1)?.targetId
              }
         })
 
@@ -961,7 +961,7 @@ describe('MCP Server Tests', () => {
             name: 'execute',
             arguments: {
                 code: js`
-          const logs = await getLatestLogs({ searchFilter: 'error' });
+          const logs = await getLatestLogs({ search: 'error' });
           logs.forEach(log => console.log(log));
         `,
             },

playwriter/src/mcp.ts

@@ -8,6 +8,7 @@ import { spawn } from 'node:child_process'
 import { createRequire } from 'node:module'
 import vm from 'node:vm'
 import dedent from 'string-dedent'
+import { createPatch } from 'diff'
 import { getCdpUrl } from './utils.js'
 
 const require = createRequire(import.meta.url)
@@ -51,6 +52,7 @@ interface VMContext {
     page: Page
     search?: string | RegExp
     contextLines?: number
+    showDiffSinceLastCall?: boolean
   }) => Promise<string>
   getLocatorStringForElement: (element: any) => Promise<string>
   resetPlaywright: () => Promise<{ page: Page; context: BrowserContext }>
@@ -77,6 +79,9 @@ const userState: Record<string, any> = {}
 const browserLogs: Map<string, string[]> = new Map()
 const MAX_LOGS_PER_PAGE = 5000
 
+// Store last accessibility snapshot per page for diff feature
+const lastSnapshots: WeakMap<Page, string> = new WeakMap()
+
 const RELAY_PORT = 19988
 const NO_TABS_ERROR = `No browser tabs are connected. Please install and enable the Playwriter extension on at least one tab: https://chromewebstore.google.com/detail/playwriter-mcp/jfeammnjpkecdekppnclgkkffahnhfhe`
 
@@ -390,12 +395,30 @@ server.tool(
         page: Page
         search?: string | RegExp
         contextLines?: number
+        showDiffSinceLastCall?: boolean
       }) => {
-        const { page: targetPage, search, contextLines = 10 } = options
+        const { page: targetPage, search, contextLines = 10, showDiffSinceLastCall = false } = options
         if ((targetPage as any)._snapshotForAI) {
           const snapshot = await (targetPage as any)._snapshotForAI()
           const snapshotStr = typeof snapshot === 'string' ? snapshot : JSON.stringify(snapshot, null, 2)
 
+          if (showDiffSinceLastCall) {
+            const previousSnapshot = lastSnapshots.get(targetPage)
+            lastSnapshots.set(targetPage, snapshotStr)
+
+            if (!previousSnapshot) {
+              return 'No previous snapshot available. This is the first call for this page. Full snapshot stored for next diff.'
+            }
+
+            const patch = createPatch('snapshot', previousSnapshot, snapshotStr, 'previous', 'current')
+            if (patch.split('\n').length <= 4) {
+              return 'No changes detected since last snapshot'
+            }
+            return patch
+          }
+
+          lastSnapshots.set(targetPage, snapshotStr)
+
           if (!search) {
             return snapshotStr
           }

playwriter/src/prompt.md

@@ -72,10 +72,11 @@ always detach event listener you create at the end of a message using `page.remo
 
 you have access to some functions in addition to playwright methods:
 
-- `async accessibilitySnapshot({ page, search, contextLines })`: gets a human readable snapshot of clickable elements on the page. useful to see the overall structure of the page and what elements you can interact with.
+- `async accessibilitySnapshot({ page, search, contextLines, showDiffSinceLastCall })`: gets a human readable snapshot of clickable elements on the page. useful to see the overall structure of the page and what elements you can interact with.
     - `page`: the page object to snapshot
     - `search`: (optional) a string or regex to filter the snapshot. If provided, returns the first 10 matches with surrounding context
     - `contextLines`: (optional) number of lines of context to show around each match (default: 10)
+    - `showDiffSinceLastCall`: (optional) if true, returns a unified diff patch showing only changes since the last snapshot call for this page. Disables search when enabled. Useful to see what changed after an action.
 - `getLatestLogs({ page, count, search })`: retrieves browser console logs. The system automatically captures and stores up to 5000 logs per page. Logs are cleared when a page reloads or navigates.
     - `page`: (optional) filter logs by a specific page instance. Only returns logs from that page
     - `count`: (optional) limit number of logs to return. If not specified, returns all available logs