diff --git a/packages/app/src/new-session/composer-adapter.ts b/packages/app/src/new-session/composer-adapter.ts
index 548669aa9fc8..7e9ca3dba4dc 100644
--- a/packages/app/src/new-session/composer-adapter.ts
+++ b/packages/app/src/new-session/composer-adapter.ts
@@ -1,6 +1,5 @@
 import { base64Encode } from "@opencode-ai/util/encode"
 import { getDirectory } from "@opencode-ai/util/path"
-import { startTransition } from "solid-js"
 import type { NewSessionComposerAdapter } from "@/composer/adapter"
 import { useComposerState } from "@/composer/persistence"
 import { createComposerControls, createComposerModelSelection } from "@/composer/selection"
@@ -72,24 +71,21 @@ export function createNewSessionComposerAdapter(props: {
       if (!created) return
 
       data.session.remember(created)
-      await startTransition(() => {
-        tabs.updateDraft(props.draftID, { worktree: undefined })
-        if (permission.isAutoAcceptingDirectory(projectDirectory)) {
-          permission.enableAutoAccept(created.id, sessionDirectory)
-        }
-        local.session.promote(sessionDirectory, created.id, {
-          agent: selection.agent,
-          model: selection.model,
-          variant: selection.variant ?? null,
-        })
-        tabs.promoteDraft(props.draftID, { server: server.key, sessionId: created.id })
-        submission.retarget(
-          prompt.capture(
-            { dir: base64Encode(sessionDirectory), id: created.id },
-            { server: server.key, scope: serverSDK.scope },
-          ),
-        )
+      if (permission.isAutoAcceptingDirectory(projectDirectory)) {
+        permission.enableAutoAccept(created.id, sessionDirectory)
+      }
+      local.session.promote(sessionDirectory, created.id, {
+        agent: selection.agent,
+        model: selection.model,
+        variant: selection.variant ?? null,
       })
+      await tabs.promoteDraft(props.draftID, { server: server.key, sessionId: created.id })
+      submission.retarget(
+        prompt.capture(
+          { dir: base64Encode(sessionDirectory), id: created.id },
+          { server: server.key, scope: serverSDK.scope },
+        ),
+      )
 
       return {
         id: created.id,
diff --git a/packages/app/src/shell/routes/routes.tsx b/packages/app/src/shell/routes/routes.tsx
index 42851b622346..7b94b828158f 100644
--- a/packages/app/src/shell/routes/routes.tsx
+++ b/packages/app/src/shell/routes/routes.tsx
@@ -1,4 +1,4 @@
-import { Route, useParams } from "@solidjs/router"
+import { Navigate, Route, useParams } from "@solidjs/router"
 import { createMemo, lazy, Show, type ParentProps } from "solid-js"
 import { Home } from "@/home/route"
 import { ServerProvider } from "@/runtime/server/current"
@@ -6,7 +6,7 @@ import { useGlobal } from "@/runtime/server/runtime"
 import { ServerConnection } from "@/runtime/server/registry"
 import { LayoutProvider } from "@/shell/state/layout"
 import Shell from "@/shell/shell"
-import { requireServerKey } from "./session"
+import { parseServerKey } from "./session"
 
 export const File = lazy(() => import("@opencode-ai/session-ui/file").then((module) => ({ default: module.File })))
 const loadDraftRoute = () => Promise.all([import("@/new-session/route"), File.preload()]).then(([module]) => module)
@@ -44,12 +44,14 @@ export function AppRoutes() {
 function TargetServerRoute(props: ParentProps) {
   const params = useParams<{ serverKey: string }>()
   const global = useGlobal()
-  const connection = createMemo(() =>
-    global.servers.list().find((item) => ServerConnection.key(item) === requireServerKey(params.serverKey)),
-  )
+  const connection = createMemo(() => {
+    const key = parseServerKey(params.serverKey)
+    if (!key) return
+    return global.servers.list().find((item) => ServerConnection.key(item) === key)
+  })
 
   return (
-    <Show when={connection()} keyed>
+    <Show when={connection()} keyed fallback={<Navigate href="/" />}>
       {(connection) => <ServerProvider conn={connection}>{props.children}</ServerProvider>}
     </Show>
   )
diff --git a/packages/app/src/shell/routes/session.test.ts b/packages/app/src/shell/routes/session.test.ts
index de3101866539..3b79fe390c3a 100644
--- a/packages/app/src/shell/routes/session.test.ts
+++ b/packages/app/src/shell/routes/session.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, test } from "bun:test"
 import { ServerConnection } from "@/runtime/server/registry"
-import { requireServerKey, rootSession, sessionHref } from "./session"
+import { parseServerKey, requireServerKey, rootSession, sessionHref } from "./session"
 
 describe("session routes", () => {
   test("builds and decodes a server-keyed session route", () => {
@@ -12,6 +12,8 @@ describe("session routes", () => {
   })
 
   test("rejects malformed server keys", () => {
+    expect(parseServerKey(undefined)).toBeUndefined()
+    expect(parseServerKey("not-base64")).toBeUndefined()
     expect(() => requireServerKey("not-base64")).toThrow("Invalid server route")
   })
 
diff --git a/packages/app/src/shell/routes/session.ts b/packages/app/src/shell/routes/session.ts
index 01c8b9e47ae5..8d3cab37e7e8 100644
--- a/packages/app/src/shell/routes/session.ts
+++ b/packages/app/src/shell/routes/session.ts
@@ -7,8 +7,14 @@ export function sessionHref(server: ServerConnection.Key, sessionID: string) {
 }
 
 export function requireServerKey(segment: string | undefined) {
+  const key = parseServerKey(segment)
+  if (!key) throw new Error("Invalid server route")
+  return key
+}
+
+export function parseServerKey(segment: string | undefined) {
   const key = decode64(segment)
-  if (!key || base64Encode(key) !== segment) throw new Error("Invalid server route")
+  if (!key || base64Encode(key) !== segment) return
   return ServerConnection.Key.make(key)
 }
 
diff --git a/packages/app/src/shell/tabs/tabs.tsx b/packages/app/src/shell/tabs/tabs.tsx
index 7767ce17efdf..7e3da89a3f06 100644
--- a/packages/app/src/shell/tabs/tabs.tsx
+++ b/packages/app/src/shell/tabs/tabs.tsx
@@ -229,12 +229,12 @@ export const { use: useTabs, provider: TabsProvider } = createSimpleContext({
           )
         })
       },
-      promoteDraft(draftID: string, session: Omit<SessionTab, "type">) {
+      async promoteDraft(draftID: string, session: Omit<SessionTab, "type">) {
         // Keep the replacement and navigation atomic so /new-session never renders
         // after its backing draft tab has been removed from the store.
         const active = location.pathname === "/new-session" && location.query.draftId === draftID
         const next = { type: "session" as const, ...session }
-        void startTransition(() => {
+        await startTransition(() => {
           setStore(
             produce((tabs) => {
               const index = tabs.findIndex((tab) => tab.type === "draft" && tab.draftID === draftID)