From bf60b53f515b284d10ab6974018d961c15c6ee5a Mon Sep 17 00:00:00 2001
From: Owen <33508519+lxxonx@users.noreply.github.com>
Date: Fri, 16 Jan 2026 18:20:40 +0900
Subject: [PATCH 1/2] fix(tui): show warning when opening WebUI without server
 mode

When OpenCode runs without --port flag, it uses internal RPC
communication with 'opencode.internal' as a placeholder URL.
The 'Open WebUI' command was trying to open this non-resolvable
URL in the browser, which fails silently.

This change adds a check for the internal URL and shows a helpful
warning toast explaining how to enable server mode instead.
---
 packages/opencode/src/cli/cmd/tui/app.tsx | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/packages/opencode/src/cli/cmd/tui/app.tsx b/packages/opencode/src/cli/cmd/tui/app.tsx
index 1fea3f4b305..d145547239a 100644
--- a/packages/opencode/src/cli/cmd/tui/app.tsx
+++ b/packages/opencode/src/cli/cmd/tui/app.tsx
@@ -465,6 +465,15 @@ function App() {
       title: "Open WebUI",
       value: "webui.open",
       onSelect: () => {
+        if (sdk.url.includes("opencode.internal")) {
+          toast.show({
+            variant: "warning",
+            message: "WebUI requires server mode. Restart with: opencode --port 4096",
+            duration: 5000,
+          })
+          dialog.clear()
+          return
+        }
         open(sdk.url).catch(() => {})
         dialog.clear()
       },

From 4b8ae9298e4c9fc093596ec1bcd6ffb27268afd8 Mon Sep 17 00:00:00 2001
From: lxxonx <leeonechang92@gmail.com>
Date: Sat, 17 Jan 2026 12:26:21 +0900
Subject: [PATCH 2/2] feat(tui): start server on-demand when opening WebUI

Instead of showing a warning when WebUI is requested without server mode,
automatically start the server and open the actual WebUI page.
---
 packages/opencode/src/cli/cmd/tui/app.tsx     | 35 +++++++++++++++----
 .../opencode/src/cli/cmd/tui/context/sdk.tsx  | 10 ++++--
 packages/opencode/src/cli/cmd/tui/thread.ts   |  6 ++++
 3 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/packages/opencode/src/cli/cmd/tui/app.tsx b/packages/opencode/src/cli/cmd/tui/app.tsx
index d145547239a..ee389a0525a 100644
--- a/packages/opencode/src/cli/cmd/tui/app.tsx
+++ b/packages/opencode/src/cli/cmd/tui/app.tsx
@@ -105,6 +105,7 @@ export function tui(input: {
   directory?: string
   fetch?: typeof fetch
   events?: EventSource
+  startServer?: () => Promise<string>
   onExit?: () => Promise<void>
 }) {
   // promise to prevent immediate exit
@@ -131,6 +132,7 @@ export function tui(input: {
                         directory={input.directory}
                         fetch={input.fetch}
                         events={input.events}
+                        startServer={input.startServer}
                       >
                         <SyncProvider>
                           <ThemeProvider mode={mode}>
@@ -464,17 +466,36 @@ function App() {
     {
       title: "Open WebUI",
       value: "webui.open",
-      onSelect: () => {
+      onSelect: async () => {
+        let url = sdk.url
         if (sdk.url.includes("opencode.internal")) {
+          if (!sdk.startServer) {
+            toast.show({
+              variant: "warning",
+              message: "WebUI requires server mode. Restart with: opencode --port 4096",
+              duration: 5000,
+            })
+            dialog.clear()
+            return
+          }
           toast.show({
-            variant: "warning",
-            message: "WebUI requires server mode. Restart with: opencode --port 4096",
-            duration: 5000,
+            variant: "info",
+            message: "Starting server...",
+            duration: 2000,
           })
-          dialog.clear()
-          return
+          try {
+            url = await sdk.startServer()
+          } catch (e) {
+            toast.show({
+              variant: "error",
+              message: "Failed to start server",
+              duration: 3000,
+            })
+            dialog.clear()
+            return
+          }
         }
-        open(sdk.url).catch(() => {})
+        open(url).catch(() => {})
         dialog.clear()
       },
       category: "System",
diff --git a/packages/opencode/src/cli/cmd/tui/context/sdk.tsx b/packages/opencode/src/cli/cmd/tui/context/sdk.tsx
index 3339e7b00d2..549fd336678 100644
--- a/packages/opencode/src/cli/cmd/tui/context/sdk.tsx
+++ b/packages/opencode/src/cli/cmd/tui/context/sdk.tsx
@@ -9,7 +9,13 @@ export type EventSource = {
 
 export const { use: useSDK, provider: SDKProvider } = createSimpleContext({
   name: "SDK",
-  init: (props: { url: string; directory?: string; fetch?: typeof fetch; events?: EventSource }) => {
+  init: (props: {
+    url: string
+    directory?: string
+    fetch?: typeof fetch
+    events?: EventSource
+    startServer?: () => Promise<string>
+  }) => {
     const abort = new AbortController()
     const sdk = createOpencodeClient({
       baseUrl: props.url,
@@ -89,6 +95,6 @@ export const { use: useSDK, provider: SDKProvider } = createSimpleContext({
       if (timer) clearTimeout(timer)
     })
 
-    return { client: sdk, event: emitter, url: props.url }
+    return { client: sdk, event: emitter, url: props.url, startServer: props.startServer }
   },
 })
diff --git a/packages/opencode/src/cli/cmd/tui/thread.ts b/packages/opencode/src/cli/cmd/tui/thread.ts
index 05714268545..3e51f391f28 100644
--- a/packages/opencode/src/cli/cmd/tui/thread.ts
+++ b/packages/opencode/src/cli/cmd/tui/thread.ts
@@ -151,6 +151,12 @@ export const TuiThreadCommand = cmd({
         model: args.model,
         prompt,
       },
+      startServer: shouldStartServer
+        ? undefined
+        : async () => {
+            const server = await client.call("server", networkOpts)
+            return server.url
+          },
       onExit: async () => {
         await client.call("shutdown", undefined)
       },