From 77b2e0ed1a94facb8fe78ea251f8dd0652c98ab2 Mon Sep 17 00:00:00 2001
From: Ronny <info@rdsport.de>
Date: Fri, 11 Sep 2026 17:34:08 +0200
Subject: [PATCH] fix(app): handle session.error events in global sync

---
 .../context/global-sync/event-reducer.test.ts | 42 +++++++++++++++++++
 .../src/context/global-sync/event-reducer.ts  | 25 +++++++++++
 packages/app/src/context/server-sync.tsx      |  6 +++
 3 files changed, 73 insertions(+)

diff --git a/packages/app/src/context/global-sync/event-reducer.test.ts b/packages/app/src/context/global-sync/event-reducer.test.ts
index 06d536618e05..60f12ee759fb 100644
--- a/packages/app/src/context/global-sync/event-reducer.test.ts
+++ b/packages/app/src/context/global-sync/event-reducer.test.ts
@@ -613,4 +613,46 @@ describe("applyDirectoryEvent", () => {
     expect(pushes).toEqual(["/tmp"])
     expect(lspLoads).toBe(1)
   })
+
+  test("handles session.error by setting session status to idle and updating assistant error", () => {
+    const errors: Array<string | undefined> = []
+    const assistantMsg = {
+      id: "msg_2",
+      sessionID: "s1",
+      role: "assistant",
+      time: { created: 2 },
+      modelID: "gpt",
+      providerID: "openai",
+    } as Message
+    const [store, setStore] = createStore(
+      baseState({
+        session_status: { s1: { type: "busy" } },
+        message: { s1: [userMessage("msg_1", "s1"), assistantMsg] },
+      }),
+    )
+
+    applyDirectoryEvent({
+      event: {
+        type: "session.error",
+        properties: {
+          sessionID: "s1",
+          error: { name: "ProviderAuthError", data: { message: "Invalid API key" } },
+        },
+      },
+      store,
+      setStore,
+      push: () => undefined,
+      directory: "/tmp",
+      loadLsp: () => undefined,
+      notifyError: (message) => errors.push(message),
+    })
+
+    expect(store.session_status.s1).toEqual({ type: "idle" })
+    const lastMsg = store.message.s1[1]
+    expect(lastMsg?.role === "assistant" ? lastMsg.error : undefined).toEqual({
+      name: "UnknownError",
+      data: { message: "Invalid API key" },
+    })
+    expect(errors).toEqual(["Invalid API key"])
+  })
 })
diff --git a/packages/app/src/context/global-sync/event-reducer.ts b/packages/app/src/context/global-sync/event-reducer.ts
index b84d5201cf55..1e2fd13980d3 100644
--- a/packages/app/src/context/global-sync/event-reducer.ts
+++ b/packages/app/src/context/global-sync/event-reducer.ts
@@ -119,6 +119,7 @@ export function applyDirectoryEvent(input: {
   retainedLimit?: number
   sessionContent?: boolean
   permission?: State["permission"]
+  notifyError?: (message?: string) => void
 }) {
   const event = input.event
   if (input.sessionContent === false && SESSION_CONTENT_EVENTS.has(event.type)) return
@@ -467,6 +468,30 @@ export function applyDirectoryEvent(input: {
       )
       break
     }
+    case "session.error": {
+      const props = event.properties as {
+        sessionID?: string
+        error?: { name?: string; data?: { message?: string }; message?: string }
+      }
+      const sessionID = props.sessionID
+      if (!sessionID) break
+      input.setStore("session_status", sessionID, { type: "idle" })
+      const errorMsg =
+        props.error?.data?.message ?? props.error?.message ?? (typeof props.error === "string" ? props.error : undefined)
+      const messages = input.store.message[sessionID]
+      if (messages && messages.length > 0) {
+        const lastMsg = messages.at(-1)
+        if (lastMsg && lastMsg.role === "assistant") {
+          input.setStore("message", sessionID, messages.length - 1, (msg) => ({
+            ...msg,
+            error: { name: "UnknownError" as const, data: { message: errorMsg ?? "" } },
+            finish: "error",
+          }))
+        }
+      }
+      input.notifyError?.(errorMsg)
+      break
+    }
     case "lsp.updated": {
       input.loadLsp()
       break
diff --git a/packages/app/src/context/server-sync.tsx b/packages/app/src/context/server-sync.tsx
index 13a0b74bc6f3..901e5914c39d 100644
--- a/packages/app/src/context/server-sync.tsx
+++ b/packages/app/src/context/server-sync.tsx
@@ -608,6 +608,12 @@ export function createServerSyncContextInner(serverSDK: ServerSDK) {
       retainedLimit: sessionMeta.get(key)?.limit,
       sessionContent: false,
       permission: session.data.permission,
+      notifyError: (message) =>
+        showToast({
+          variant: "error",
+          title: language.t("notification.session.error.title"),
+          description: message ?? language.t("notification.session.error.fallbackDescription"),
+        }),
       vcsCache: children.vcsCache.get(key),
       loadLsp: () => {
         if (!children.active(key)) return