diff --git a/.changeset/five-sheep-count.md b/.changeset/five-sheep-count.md
new file mode 100644
index 0000000000..3ad45bf471
--- /dev/null
+++ b/.changeset/five-sheep-count.md
@@ -0,0 +1,5 @@
+---
+"claude-dev": patch
+---
+
+openInBrowser protobus migration
diff --git a/proto/web.proto b/proto/web.proto
index 3debacbc30..0df3b6e8e5 100644
--- a/proto/web.proto
+++ b/proto/web.proto
@@ -9,6 +9,7 @@ import "common.proto";
 service WebService {
   rpc checkIsImageUrl(StringRequest) returns (IsImageUrl);
   rpc fetchOpenGraphData(StringRequest) returns (OpenGraphData);
+  rpc openInBrowser(StringRequest) returns (Empty);
 }
 
 message IsImageUrl {
diff --git a/src/core/controller/index.ts b/src/core/controller/index.ts
index 2b318fbcc3..9cf8b45e9d 100644
--- a/src/core/controller/index.ts
+++ b/src/core/controller/index.ts
@@ -303,11 +303,6 @@ export class Controller {
 					text: message.text,
 				})
 				break
-			case "openInBrowser":
-				if (message.url) {
-					vscode.env.openExternal(vscode.Uri.parse(message.url))
-				}
-				break
 			case "fetchUserCreditsData": {
 				await this.fetchUserCreditsData()
 				break
diff --git a/src/core/controller/web/openInBrowser.ts b/src/core/controller/web/openInBrowser.ts
new file mode 100644
index 0000000000..e31d86d602
--- /dev/null
+++ b/src/core/controller/web/openInBrowser.ts
@@ -0,0 +1,21 @@
+import * as vscode from "vscode"
+import { Controller } from ".."
+import { Empty, StringRequest } from "../../../shared/proto/common"
+
+/**
+ * Opens a URL in the user's default browser
+ * @param controller The controller instance
+ * @param request The URL to open
+ * @returns Empty response since the client doesn't need a return value
+ */
+export async function openInBrowser(controller: Controller, request: StringRequest): Promise<Empty> {
+	try {
+		if (request.value) {
+			await vscode.env.openExternal(vscode.Uri.parse(request.value))
+		}
+		return Empty.create()
+	} catch (error) {
+		console.error("Error opening URL in browser:", error)
+		return Empty.create()
+	}
+}
diff --git a/src/shared/WebviewMessage.ts b/src/shared/WebviewMessage.ts
index de0adb7c36..4ea2a4dc7b 100644
--- a/src/shared/WebviewMessage.ts
+++ b/src/shared/WebviewMessage.ts
@@ -13,7 +13,6 @@ export interface WebviewMessage {
 		| "newTask"
 		| "condense"
 		| "reportBug"
-		| "openInBrowser"
 		| "showChatView"
 		| "requestVsCodeLmModels"
 		| "authStateChanged"
@@ -54,8 +53,6 @@ export interface WebviewMessage {
 	// For auth
 	user?: UserInfo | null
 	customToken?: string
-	// For openInBrowser
-	url?: string
 	planActSeparateModelsSetting?: boolean
 	enableCheckpointsSetting?: boolean
 	mcpMarketplaceEnabled?: boolean
diff --git a/webview-ui/src/components/mcp/chat-display/ImagePreview.tsx b/webview-ui/src/components/mcp/chat-display/ImagePreview.tsx
index bbe7ae605f..5cf70cbf79 100644
--- a/webview-ui/src/components/mcp/chat-display/ImagePreview.tsx
+++ b/webview-ui/src/components/mcp/chat-display/ImagePreview.tsx
@@ -1,5 +1,6 @@
 import React from "react"
 import { vscode } from "@/utils/vscode"
+import { WebServiceClient } from "@/services/grpc-client"
 import DOMPurify from "dompurify"
 import { getSafeHostname, formatUrlForOpening, checkIfImageUrl } from "./utils/mcpRichUtil"
 import ChatErrorBoundary from "@/components/chat/ChatErrorBoundary"
@@ -232,11 +233,14 @@ class ImagePreview extends React.Component<
 						borderRadius: "4px",
 						color: "var(--vscode-errorForeground)",
 					}}
-					onClick={() => {
-						vscode.postMessage({
-							type: "openInBrowser",
-							url: DOMPurify.sanitize(url),
-						})
+					onClick={async () => {
+						try {
+							await WebServiceClient.openInBrowser({
+								value: DOMPurify.sanitize(url),
+							})
+						} catch (err) {
+							console.error("Error opening URL in browser:", err)
+						}
 					}}>
 					<div style={{ fontWeight: "bold" }}>Failed to load image</div>
 					<div style={{ fontSize: "12px", marginTop: "4px" }}>{getSafeHostname(url)}</div>
@@ -256,11 +260,14 @@ class ImagePreview extends React.Component<
 					maxWidth: "100%",
 					cursor: "pointer",
 				}}
-				onClick={() => {
-					vscode.postMessage({
-						type: "openInBrowser",
-						url: DOMPurify.sanitize(formatUrlForOpening(url)),
-					})
+				onClick={async () => {
+					try {
+						await WebServiceClient.openInBrowser({
+							value: DOMPurify.sanitize(formatUrlForOpening(url)),
+						})
+					} catch (err) {
+						console.error("Error opening URL in browser:", err)
+					}
 				}}>
 				{/\.svg(\?.*)?$/i.test(url) ? (
 					// Special handling for SVG images
diff --git a/webview-ui/src/components/mcp/chat-display/LinkPreview.tsx b/webview-ui/src/components/mcp/chat-display/LinkPreview.tsx
index 0e408590b5..232a7898e4 100644
--- a/webview-ui/src/components/mcp/chat-display/LinkPreview.tsx
+++ b/webview-ui/src/components/mcp/chat-display/LinkPreview.tsx
@@ -238,11 +238,14 @@ class LinkPreview extends React.Component<LinkPreviewProps, LinkPreviewState> {
 						maxWidth: "512px",
 						overflow: "auto",
 					}}
-					onClick={() => {
-						vscode.postMessage({
-							type: "openInBrowser",
-							url: DOMPurify.sanitize(url),
-						})
+					onClick={async () => {
+						try {
+							await WebServiceClient.openInBrowser({
+								value: DOMPurify.sanitize(url),
+							})
+						} catch (err) {
+							console.error("Error opening URL in browser:", err)
+						}
 					}}>
 					<div style={{ fontWeight: "bold" }}>{errorDisplay}</div>
 					<div style={{ fontSize: "12px", marginTop: "4px" }}>{getSafeHostname(url)}</div>
@@ -275,11 +278,14 @@ class LinkPreview extends React.Component<LinkPreviewProps, LinkPreviewState> {
 					height: "128px",
 					maxWidth: "512px",
 				}}
-				onClick={() => {
-					vscode.postMessage({
-						type: "openInBrowser",
-						url: DOMPurify.sanitize(url),
-					})
+				onClick={async () => {
+					try {
+						await WebServiceClient.openInBrowser({
+							value: DOMPurify.sanitize(url),
+						})
+					} catch (err) {
+						console.error("Error opening URL in browser:", err)
+					}
 				}}>
 				{data.image && (
 					<div className="link-preview-image" style={{ width: "128px", height: "128px", flexShrink: 0 }}>