diff --git a/package.json b/package.json
index a1e8214..7557b68 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,7 @@
   },
   "author": "Neek Sandhu <neek.sandhu@outlook.com>",
   "scripts": {
-    "build": "tsup src/index.ts src/background.ts src/content-script.ts src/devtools.ts src/options.ts src/popup.ts src/window.ts --format esm,cjs --dts",
+    "build": "tsup src/index.ts src/background.ts src/content-script.ts src/devtools.ts src/options.ts src/popup.ts src/window.ts src/sidepanel.ts --format esm,cjs --dts",
     "watch": "npm run build -- --watch",
     "release": "bumpp --commit --push --tag && npm run build && npm publish"
   },
@@ -55,6 +55,10 @@
     "./window": {
       "import": "./dist/window.js",
       "require": "./dist/window.cjs"
+    },
+    "./sidepanel": {
+      "import": "./dist/sidepanel.js",
+      "require": "./dist/sidepanel.cjs"
     }
   },
   "typesVersions": {
@@ -79,6 +83,9 @@
       ],
       "window": [
         "dist/window.d.ts"
+      ],
+      "sidepanel": [
+        "dist/sidepanel.d.ts"
       ]
     }
   },
diff --git a/src/background.ts b/src/background.ts
index de77f84..8a1e528 100644
--- a/src/background.ts
+++ b/src/background.ts
@@ -240,6 +240,23 @@ browser.runtime.onConnect.addListener((incomingPort) => {
     frameId: incomingPort.sender.frameId,
   })
 
+  // For sidepanel, popup, options and devtools, we need the tab ID of the current tab
+  if (['sidepanel', 'popup', 'options', 'devtools'].includes(parseEndpoint(connArgs.endpointName).context)) {
+    browser.tabs.query({ active: true, currentWindow: true }).then(tabs => {
+      if (tabs[0]) {
+        const activeTabId = tabs[0].id
+        // Update the endpoint name with the active tab ID for sidepanel
+        if (parseEndpoint(connArgs.endpointName).context === 'sidepanel' &&
+            parseEndpoint(connArgs.endpointName).tabId == null) {
+          connArgs.endpointName = formatEndpoint({
+            context: 'sidepanel',
+            tabId: activeTabId,
+          })
+        }
+      }
+    })
+  }
+
   // literal tab id in case of content script, however tab id of inspected page in case of devtools context
   const { tabId: linkedTabId, frameId: linkedFrameId } = parseEndpoint(
     connArgs.endpointName,
diff --git a/src/internal/endpoint.ts b/src/internal/endpoint.ts
index 0c271f2..86ebd95 100644
--- a/src/internal/endpoint.ts
+++ b/src/internal/endpoint.ts
@@ -1,6 +1,6 @@
 import type { Endpoint, RuntimeContext } from '../types'
 
-const ENDPOINT_RE = /^((?:background$)|devtools|popup|options|content-script|window)(?:@(\d+)(?:\.(\d+))?)?$/
+const ENDPOINT_RE = /^((?:background$)|devtools|popup|options|content-script|window|sidepanel)(?:@(\d+)(?:\.(\d+))?)?$/
 
 export const parseEndpoint = (endpoint: string): Endpoint => {
   const [, context, tabId, frameId] = endpoint.match(ENDPOINT_RE) || []
@@ -13,7 +13,7 @@ export const parseEndpoint = (endpoint: string): Endpoint => {
 }
 
 export const formatEndpoint = ({ context, tabId, frameId }: Endpoint): string => {
-  if (['background', 'popup', 'options'].includes(context))
+  if (['background', 'popup', 'options', 'sidepanel'].includes(context))
     return context
 
   return `${context}@${tabId}${frameId ? `.${frameId}` : ''}`
diff --git a/src/internal/is-internal-endpoint.ts b/src/internal/is-internal-endpoint.ts
index 5e6ab4c..712639f 100644
--- a/src/internal/is-internal-endpoint.ts
+++ b/src/internal/is-internal-endpoint.ts
@@ -1,5 +1,5 @@
 import type { Endpoint, RuntimeContext } from '../types'
 
-const internalEndpoints: RuntimeContext[] = ['background', 'devtools', 'content-script', 'options', 'popup']
+const internalEndpoints: RuntimeContext[] = ['background', 'devtools', 'content-script', 'options', 'popup', 'sidepanel']
 
 export const isInternalEndpoint = ({ context: ctx }: Endpoint): boolean => internalEndpoints.includes(ctx)
diff --git a/src/sidepanel.ts b/src/sidepanel.ts
new file mode 100644
index 0000000..8b85990
--- /dev/null
+++ b/src/sidepanel.ts
@@ -0,0 +1,108 @@
+import { createEndpointRuntime } from './internal/endpoint-runtime'
+import { createStreamWirings } from './internal/stream'
+import { createPersistentPort } from './internal/persistent-port'
+import browser from 'webextension-polyfill'
+
+// Chrome API types for sidepanel
+declare global {
+  interface Chrome {
+    sidePanel?: {
+      setPanelBehavior: (options: { openPanelOnActionClick: boolean }) => void
+      setOptions: (options: { path?: string }) => void
+      onShown: {
+        addListener: (callback: () => void) => void
+        removeListener: (callback: () => void) => void
+        hasListener: (callback: () => void) => boolean
+      }
+      onHidden: {
+        addListener: (callback: () => void) => void
+        removeListener: (callback: () => void) => void
+        hasListener: (callback: () => void) => boolean
+      }
+      // V3 还支持指定页面的侧边栏配置
+      getOptions: (options: { tabId?: number }) => Promise<{ path?: string }>
+    }
+  }
+  var chrome: Chrome | undefined
+}
+
+const port = createPersistentPort('sidepanel')
+const endpointRuntime = createEndpointRuntime(
+  'sidepanel',
+  message => port.postMessage(message),
+)
+
+port.onMessage(endpointRuntime.handleMessage)
+
+/**
+ * Set up Chrome's sidepanel API for Manifest V3 extensions
+ *
+ * This function initializes the Chrome sidepanel API and configures its behavior.
+ * Use this in your sidepanel entry point to ensure the sidepanel works correctly.
+ *
+ * Example usage in your sidepanel script:
+ *
+ * ```ts
+ * import { setupSidepanel, sendMessage } from 'webext-bridge/sidepanel'
+ *
+ * // Initialize the sidepanel
+ * setupSidepanel({ defaultPath: 'sidepanel.html' })
+ *
+ * // Send a message to background
+ * sendMessage('get-data', { key: 'value' }, 'background')
+ *   .then(response => console.log(response))
+ *
+ * // Listen for messages from other contexts
+ * onMessage('update-sidebar', (message) => {
+ *   console.log(message.data)
+ *   // Update sidebar UI
+ * })
+ * ```
+ *
+ * @param options Configuration options for the sidepanel
+ * @param options.defaultPath Default HTML path for the sidepanel
+ */
+export function setupSidepanel(options: { defaultPath?: string } = {}) {
+  if (typeof chrome !== 'undefined' && chrome.sidePanel) {
+    // Chrome specific sidepanel API
+    chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true })
+
+    if (options.defaultPath) {
+      chrome.sidePanel.setOptions({ path: options.defaultPath })
+    }
+  }
+}
+
+/**
+ * 注册侧边栏显示事件的回调函数
+ * @param callback 当侧边栏显示时要执行的回调函数
+ * @returns 用于移除事件监听器的函数
+ */
+export function onSidepanelShown(callback: () => void): () => void {
+  if (typeof chrome !== 'undefined' && chrome.sidePanel && chrome.sidePanel.onShown) {
+    chrome.sidePanel.onShown.addListener(callback)
+    return () => chrome.sidePanel.onShown.removeListener(callback)
+  }
+  return () => {}
+}
+
+/**
+ * 注册侧边栏隐藏事件的回调函数
+ * @param callback 当侧边栏隐藏时要执行的回调函数
+ * @returns 用于移除事件监听器的函数
+ */
+export function onSidepanelHidden(callback: () => void): () => void {
+  if (typeof chrome !== 'undefined' && chrome.sidePanel && chrome.sidePanel.onHidden) {
+    chrome.sidePanel.onHidden.addListener(callback)
+    return () => chrome.sidePanel.onHidden.removeListener(callback)
+  }
+  return () => {}
+}
+
+export function isSidepanelSupported(): boolean {
+  return !!chrome.sidePanel
+}
+
+
+export const { sendMessage, onMessage } = endpointRuntime
+export const { openStream, onOpenStreamChannel } = createStreamWirings(endpointRuntime)
diff --git a/src/types.ts b/src/types.ts
index d184a5c..235d2e1 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -7,6 +7,7 @@ export type RuntimeContext =
   | 'options'
   | 'content-script'
   | 'window'
+  | 'sidepanel'
 
 export interface Endpoint {
   context: RuntimeContext