From 950aa1e950c8ccae0bcc8c780e405a61719533b8 Mon Sep 17 00:00:00 2001
From: Alexey Volkov <alexey.volkov@shopify.com>
Date: Thu, 19 Mar 2026 01:34:28 -0700
Subject: [PATCH 1/2] feat: App - Support setting base URL during build
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This is needed to host OpenCode app under under some URL prefix.
This minimal change makes it possible to build OpenCode Web App with VITE_BASE_URL="/subdir/" and have it run under `http://<host>:<port>/subdir/` instead of root (`http://<host>:<port>/`).

Set `VITE_BASE_URL` env var during build. This automatically sets the `base` in Vite config. Vite generates correct URLs in `index.html`.
`import.meta.env.BASE_URL` is also used in routers. See https://vite.dev/config/shared-options#base
You can also set `VITE_OPENCODE_SERVER_BASE_URL` to specify the base URL prefix for the server.

Usage:
```
% VITE_BASE_URL="/XXX" VITE_OPENCODE_SERVER_BASE_URL="/" bun dev
$ vite
(!) "base" option should start with a slash.

  VITE v7.1.4  ready in 320 ms

  ➜  Local:   http://localhost:3000/XXX
```
---
 packages/app/src/app.tsx    | 1 +
 packages/app/src/entry.tsx  | 6 ++++--
 packages/app/src/env.d.ts   | 1 +
 packages/app/vite.config.ts | 1 +
 4 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/app/src/app.tsx b/packages/app/src/app.tsx
index e370862212b..21a9fd3b3a4 100644
--- a/packages/app/src/app.tsx
+++ b/packages/app/src/app.tsx
@@ -279,6 +279,7 @@ export function AppInterface(props: {
           <GlobalSyncProvider>
             <Dynamic
               component={props.router ?? Router}
+              base={import.meta.env.BASE_URL.replace(/\/$/, "") || undefined}
               root={(routerProps) => <RouterRoot appChildren={props.children}>{routerProps.children}</RouterRoot>}
             >
               <Route path="/" component={HomeRoute} />
diff --git a/packages/app/src/entry.tsx b/packages/app/src/entry.tsx
index b5cbed6e75d..f62dc78b024 100644
--- a/packages/app/src/entry.tsx
+++ b/packages/app/src/entry.tsx
@@ -99,9 +99,11 @@ if (!(root instanceof HTMLElement) && import.meta.env.DEV) {
 
 const getCurrentUrl = () => {
   if (location.hostname.includes("opencode.ai")) return "http://localhost:4096"
+  const serverBaseUrl =
+    "/" + (import.meta.env.VITE_OPENCODE_SERVER_BASE_URL ?? "/").replace(/^\//, "").replace(/\/$/, "")
   if (import.meta.env.DEV)
-    return `http://${import.meta.env.VITE_OPENCODE_SERVER_HOST ?? "localhost"}:${import.meta.env.VITE_OPENCODE_SERVER_PORT ?? "4096"}`
-  return location.origin
+    return `http://${import.meta.env.VITE_OPENCODE_SERVER_HOST ?? "localhost"}:${import.meta.env.VITE_OPENCODE_SERVER_PORT ?? "4096"}{serverBaseUrl}`
+  return location.origin + serverBaseUrl
 }
 
 const getDefaultUrl = () => {
diff --git a/packages/app/src/env.d.ts b/packages/app/src/env.d.ts
index 89721f34f29..c8d0a7d2414 100644
--- a/packages/app/src/env.d.ts
+++ b/packages/app/src/env.d.ts
@@ -1,6 +1,7 @@
 import "solid-js"
 
 interface ImportMetaEnv {
+  readonly BASE_URL: string
   readonly VITE_OPENCODE_SERVER_HOST: string
   readonly VITE_OPENCODE_SERVER_PORT: string
 }
diff --git a/packages/app/vite.config.ts b/packages/app/vite.config.ts
index 6a29ae6345e..9c0685aa034 100644
--- a/packages/app/vite.config.ts
+++ b/packages/app/vite.config.ts
@@ -2,6 +2,7 @@ import { defineConfig } from "vite"
 import desktopPlugin from "./vite"
 
 export default defineConfig({
+  base: process.env.VITE_BASE_URL || "/",
   plugins: [desktopPlugin] as any,
   server: {
     host: "0.0.0.0",

From ae08d12ea1d002f68c4021e91eb1c04fbf570953 Mon Sep 17 00:00:00 2001
From: Alexey Volkov <alexey.volkov@shopify.com>
Date: Thu, 19 Mar 2026 02:27:48 -0700
Subject: [PATCH 2/2] Normalized the URL slashes

---
 packages/app/src/entry.tsx | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/packages/app/src/entry.tsx b/packages/app/src/entry.tsx
index f62dc78b024..d08ccaf1794 100644
--- a/packages/app/src/entry.tsx
+++ b/packages/app/src/entry.tsx
@@ -98,9 +98,10 @@ if (!(root instanceof HTMLElement) && import.meta.env.DEV) {
 }
 
 const getCurrentUrl = () => {
+  let serverBaseUrl = import.meta.env.VITE_OPENCODE_SERVER_BASE_URL ?? ""
+  // Normalizing slashes. Add starting slash if needed, remove trailing slash. Default value will be empty string.
+  serverBaseUrl = ("/" + serverBaseUrl.replace(/^\//, "")).replace(/\/$/, "")
   if (location.hostname.includes("opencode.ai")) return "http://localhost:4096"
-  const serverBaseUrl =
-    "/" + (import.meta.env.VITE_OPENCODE_SERVER_BASE_URL ?? "/").replace(/^\//, "").replace(/\/$/, "")
   if (import.meta.env.DEV)
     return `http://${import.meta.env.VITE_OPENCODE_SERVER_HOST ?? "localhost"}:${import.meta.env.VITE_OPENCODE_SERVER_PORT ?? "4096"}{serverBaseUrl}`
   return location.origin + serverBaseUrl