fix(desktop): better error messages on connection failure

3 files changed, 43 insertions, 12 deletions

diff --git a/packages/desktop/src/app.tsx b/packages/desktop/src/app.tsx
index 9d000b8ff..11216643e 100644
--- a/packages/desktop/src/app.tsx
+++ b/packages/desktop/src/app.tsx
@@ -35,10 +35,10 @@ const url = iife(() => {
 
   if (location.hostname.includes("opencode.ai")) return "http://localhost:4096"
   if (window.__OPENCODE__) return `http://127.0.0.1:${window.__OPENCODE__.port}`
-  if (import.meta.env.VITE_OPENCODE_SERVER)
-    return `http://${import.meta.env.VITE_OPENCODE_SERVER_HOST}:${import.meta.env.VITE_OPENCODE_SERVER_PORT ?? "4096"}`
+  if (import.meta.env.DEV)
+    return `http://${import.meta.env.VITE_OPENCODE_SERVER_HOST ?? "localhost"}:${import.meta.env.VITE_OPENCODE_SERVER_PORT ?? "4096"}`
 
-  return "/"
+  return "http://localhost:4096"
 })
 
 export function App() {
diff --git a/packages/desktop/src/context/global-sync.tsx b/packages/desktop/src/context/global-sync.tsx
index 27a89e7bc..ae40555d6 100644
--- a/packages/desktop/src/context/global-sync.tsx
+++ b/packages/desktop/src/context/global-sync.tsx
@@ -295,6 +295,15 @@ function createGlobalSync() {
   })
 
   async function bootstrap() {
+    const health = await globalSDK.client.global.health().then((x) => x.data)
+    if (!health?.healthy) {
+      setGlobalStore(
+        "error",
+        new Error(`Could not connect to server. Is there a server running at \`${globalSDK.url}\`?`),
+      )
+      return
+    }
+
     return Promise.all([
       retry(() =>
         globalSDK.client.path.get().then((x) => {
diff --git a/packages/desktop/src/pages/error.tsx b/packages/desktop/src/pages/error.tsx
index c7330c298..9914279ad 100644
--- a/packages/desktop/src/pages/error.tsx
+++ b/packages/desktop/src/pages/error.tsx
@@ -62,27 +62,49 @@ function formatInitError(error: InitError): string {
   }
 }
 
-function formatErrorChain(error: unknown, depth = 0): string {
+function formatErrorChain(error: unknown, depth = 0, parentMessage?: string): string {
   if (!error) return "Unknown error"
 
-  const indent = depth > 0 ? `\n${"─".repeat(40)}\nCaused by:\n` : ""
-
   if (isInitError(error)) {
-    return indent + formatInitError(error)
+    const message = formatInitError(error)
+    if (depth > 0 && parentMessage === message) return ""
+    const indent = depth > 0 ? `\n${"─".repeat(40)}\nCaused by:\n` : ""
+    return indent + message
   }
 
   if (error instanceof Error) {
-    const parts = [indent + `${error.name}: ${error.message}`]
-    if (error.stack) {
-      parts.push(error.stack)
+    const isDuplicate = depth > 0 && parentMessage === error.message
+    const parts: string[] = []
+    const indent = depth > 0 ? `\n${"─".repeat(40)}\nCaused by:\n` : ""
+
+    if (!isDuplicate) {
+      // Stack already includes error name and message, so prefer it
+      parts.push(indent + (error.stack ?? `${error.name}: ${error.message}`))
+    } else if (error.stack) {
+      // Duplicate message - only show the stack trace lines (skip message)
+      const trace = error.stack.split("\n").slice(1).join("\n").trim()
+      if (trace) {
+        parts.push(trace)
+      }
     }
+
     if (error.cause) {
-      parts.push(formatErrorChain(error.cause, depth + 1))
+      const causeResult = formatErrorChain(error.cause, depth + 1, error.message)
+      if (causeResult) {
+        parts.push(causeResult)
+      }
     }
+
     return parts.join("\n\n")
   }
 
-  if (typeof error === "string") return indent + error
+  if (typeof error === "string") {
+    if (depth > 0 && parentMessage === error) return ""
+    const indent = depth > 0 ? `\n${"─".repeat(40)}\nCaused by:\n` : ""
+    return indent + error
+  }
+
+  const indent = depth > 0 ? `\n${"─".repeat(40)}\nCaused by:\n` : ""
   return indent + JSON.stringify(error, null, 2)
 }