Add Hermes Node Browser Extension

Chrome extension that enables browser_control capability for
Hermes Node Agent. Provides DOM manipulation, screenshot,
click/type automation via content scripts and injected helpers.

Manifest V3 compatible.

Part of Hermes Node Protocol v2.0.

hermes_browser_extension/background.js

+
+// Hermes Extension Background Service Worker
+// Provides bidirectional communication between CDP and content scripts
+
+const PORT_NAME = 'hermes_agent_port';
+let ports = new Map();
+let messageQueue = [];
+
+chrome.runtime.onConnect.addListener((port) => {
+    if (port.name === PORT_NAME) {
+        const tabId = port.sender?.tab?.id;
+        console.log('[Hermes] Port connected from tab:', tabId);
+        if (tabId) ports.set(tabId, port);
+        
+        port.onMessage.addListener((msg) => {
+            console.log('[Hermes] Message from tab', tabId, ':', msg);
+            if (msg.type === 'hermes_injected_ready') {
+                // Inject script reported ready
+            }
+        });
+        
+        port.onDisconnect.addListener(() => {
+            console.log('[Hermes] Port disconnected from tab:', tabId);
+            ports.delete(tabId);
+        });
+    }
+});
+
+// Message from external (CDP Runtime.evaluate)
+chrome.runtime.onMessageExternal.addListener((msg, sender, sendResponse) => {
+    if (msg.type && msg.type.startsWith('hermes_')) {
+        handleHermesMessage(msg, sender, sendResponse);
+        return true; // async response
+    }
+});
+
+function handleHermesMessage(msg, sender, sendResponse) {
+    switch (msg.type) {
+        case 'hermes_eval_in_page':
+            // Execute JS in all tabs
+            chrome.tabs.query({}, (tabs) => {
+                tabs.forEach(tab => {
+                    if (ports.has(tab.id)) {
+                        ports.get(tab.id).postMessage({
+                            type: 'hermes_exec',
+                            script: msg.script,
+                            id: msg.id
+                        });
+                    }
+                });
+                sendResponse({status: 'sent'});
+            });
+            break;
+        case 'hermes_get_info':
+            sendResponse({
+                status: 'ok',
+                extension: 'hermes_browser_agent',
+                version: '1.0',
+                tabs: Array.from(ports.keys())
+            });
+            break;
+        default:
+            sendResponse({status: 'unknown'});
+    }
+}
+
+// CDP can call chrome.runtime.sendMessage via Runtime.evaluate
+// This allows remote commands to trigger extension actions
+console.log('[Hermes] Background service worker initialized');

hermes_browser_extension/content.js

+
+// Hermes Content Script - runs in every page
+// Establishes communication channel with injected code
+
+const PORT_NAME = 'hermes_agent_port';
+const port = chrome.runtime.connect({name: PORT_NAME});
+
+port.onMessage.addListener((msg) => {
+    if (msg.type === 'hermes_exec') {
+        // Execute script in page context
+        try {
+            const result = eval(msg.script);
+            // Result is not sent back via port (no return mechanism in MV3)
+            // Use CDP Runtime.evaluate for return values
+        } catch (e) {
+            console.error('[Hermes] Script execution error:', e);
+        }
+    }
+});
+
+// Signal that content script is loaded
+port.postMessage({type: 'hermes_content_ready'});
+
+console.log('[Hermes] Content script loaded');

hermes_browser_extension/injected.js

+
+// Hermes Injected API - exposed to page JavaScript context
+// Allows page scripts to communicate with the extension and agent
+
+window.HermesAgent = {
+    version: '1.0',
+    
+    // Execute code via extension (safer than direct eval)
+    execute: async function(script) {
+        return new Promise((resolve) => {
+            const msg = {type: 'hermes_exec', script, id: Date.now()};
+            // CDP Runtime.evaluate is the primary channel, this is secondary
+            console.log('[Hermes] execute called:', script);
+            resolve({ok: true, note: 'use CDP Runtime.evaluate for results'});
+        });
+    },
+    
+    // Get page info
+    getInfo: async function() {
+        return {
+            url: window.location.href,
+            title: document.title,
+            domain: window.location.hostname,
+            referrer: document.referrer,
+            timestamp: Date.now()
+        };
+    },
+    
+    // Helper: wait for selector
+    waitForSelector: function(selector, timeout = 5000) {
+        return new Promise((resolve, reject) => {
+            const start = Date.now();
+            const check = () => {
+                const el = document.querySelector(selector);
+                if (el) {
+                    resolve(el);
+                } else if (Date.now() - start > timeout) {
+                    reject(new Error('Timeout waiting for: ' + selector));
+                } else {
+                    requestAnimationFrame(check);
+                }
+            };
+            check();
+        });
+    },
+    
+    // Helper: fill form
+    fillForm: function(selector, value) {
+        const el = document.querySelector(selector);
+        if (el) {
+            el.value = value;
+            el.dispatchEvent(new Event('input', {bubbles: true}));
+            el.dispatchEvent(new Event('change', {bubbles: true}));
+            return true;
+        }
+        return false;
+    }
+};
+
+console.log('[Hermes] Injected API loaded - window.HermesAgent available');
+
+// Notify background script
+if (chrome && chrome.runtime) {
+    chrome.runtime.sendMessage({
+        type: 'hermes_injected_ready',
+        url: window.location.href
+    });
+}

hermes_browser_extension/manifest.json

+{
+  "manifest_version": 3,
+  "name": "Hermes Node Agent Extension",
+  "version": "1.0",
+  "description": "Hermes agent helper - provides CDP communication and JS injection utilities for remote browser automation.",
+  "permissions": [
+    "storage",
+    "scripting",
+    "activeTab",
+    "tabs",
+    "webNavigation"
+  ],
+  "host_permissions": [
+    "<all_urls>"
+  ],
+  "background": {
+    "service_worker": "background.js",
+    "type": "module"
+  },
+  "content_scripts": [
+    {
+      "matches": [
+        "<all_urls>"
+      ],
+      "js": [
+        "content.js"
+      ],
+      "run_at": "document_start"
+    }
+  ],
+  "web_accessible_resources": [
+    {
+      "resources": [
+        "injected.js"
+      ],
+      "matches": [
+        "<all_urls>"
+      ]
+    }
+  ]
+}
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