4 files changed, 97 insertions, 3 deletions
diff --git a/src/adapters/ws/index.test.ts b/src/adapters/ws/index.test.ts
index 6461493..e4e4ba4 100644
--- a/src/adapters/ws/index.test.ts
+++ b/src/adapters/ws/index.test.ts
@@ -499,3 +499,40 @@ it("routes chat.queued only through the typed chat callback, never surface/error
   expect(onMessage).not.toHaveBeenCalled();
   handle.close();
 });
+
+it("routes resync notices to chat without reconnect/resend or surface errors", () => {
+  vi.useFakeTimers();
+  const ws = fakeSocket();
+  const onChat = vi.fn();
+  const onMessage = vi.fn();
+  const onReopen = vi.fn();
+  const factory = vi.fn(() => ws);
+  const handle = createSurfaceSocket({
+    url: "ws://test",
+    socketFactory: factory,
+    onChat,
+    onMessage,
+    onReopen,
+  });
+  try {
+    ws.resolveOpen();
+    const notice = {
+      type: "chat.resync-required",
+      conversationId: "c1",
+      turnId: "t1",
+      reason: "replay-limit",
+    };
+    ws.invokeMessage(JSON.stringify(notice));
+    ws.invokeMessage(JSON.stringify(notice));
+    vi.advanceTimersByTime(1000);
+    expect(onChat).toHaveBeenCalledTimes(2);
+    expect(onChat).toHaveBeenCalledWith(notice);
+    expect(onMessage).not.toHaveBeenCalled();
+    expect(onReopen).not.toHaveBeenCalled();
+    expect(factory).toHaveBeenCalledTimes(1);
+    expect(ws.sent).toEqual([]);
+  } finally {
+    handle.close();
+    vi.useRealTimers();
+  }
+});
diff --git a/src/adapters/ws/index.ts b/src/adapters/ws/index.ts
index 25e9911..b1e17cf 100644
--- a/src/adapters/ws/index.ts
+++ b/src/adapters/ws/index.ts
@@ -2,6 +2,7 @@ import type {
   ChatDeltaMessage,
   ChatErrorMessage,
   ChatQueuedMessage,
+  ChatResyncRequiredMessage,
   ConversationCompactedMessage,
   ConversationOpenMessage,
   ConversationStatusChangedMessage,
@@ -25,7 +26,9 @@ export interface WebSocketLike {
 export interface SurfaceSocketOptions {
   url: string;
   onMessage: (msg: SurfaceServerMessage) => void;
-  onChat?: (msg: ChatDeltaMessage | ChatErrorMessage | ChatQueuedMessage) => void;
+  onChat?: (
+    msg: ChatDeltaMessage | ChatErrorMessage | ChatQueuedMessage | ChatResyncRequiredMessage,
+  ) => void;
   /** Broadcast when a conversation is "opened" (e.g. CLI `--open` flag). */
   onConversationOpen?: (msg: ConversationOpenMessage) => void;
   /** Broadcast when a conversation's lifecycle status changes (active/idle/closed). */
@@ -101,8 +104,19 @@ export function createSurfaceSocket(opts: SurfaceSocketOptions): SurfaceSocketHa
       if (disposed) return;
       const msg = parseServerMessage(ev.data);
       if (msg !== null) {
-        if (msg.type === "chat.delta" || msg.type === "chat.error" || msg.type === "chat.queued") {
-          opts.onChat?.(msg as ChatDeltaMessage | ChatErrorMessage | ChatQueuedMessage);
+        if (
+          msg.type === "chat.delta" ||
+          msg.type === "chat.error" ||
+          msg.type === "chat.queued" ||
+          msg.type === "chat.resync-required"
+        ) {
+          opts.onChat?.(
+            msg as
+              | ChatDeltaMessage
+              | ChatErrorMessage
+              | ChatQueuedMessage
+              | ChatResyncRequiredMessage,
+          );
         } else if (msg.type === "conversation.open") {
           opts.onConversationOpen?.(msg as ConversationOpenMessage);
         } else if (msg.type === "conversation.statusChanged") {
diff --git a/src/adapters/ws/logic.test.ts b/src/adapters/ws/logic.test.ts
index db6444a..4bc2aad 100644
--- a/src/adapters/ws/logic.test.ts
+++ b/src/adapters/ws/logic.test.ts
@@ -609,3 +609,32 @@ describe("chat.queued admission acknowledgement", () => {
     expect(JSON.parse(serialize(msg))).toEqual(msg);
   });
 });
+
+describe("chat.resync-required", () => {
+  it.each(["replay-limit", "payload-limit"])("parses %s with optional turn identity", (reason) => {
+    const msg = { type: "chat.resync-required", conversationId: "c1", reason };
+    expect(parseServerMessage(JSON.stringify(msg))).toEqual(msg);
+    expect(parseServerMessage(JSON.stringify({ ...msg, turnId: "t1" }))).toEqual({
+      ...msg,
+      turnId: "t1",
+    });
+  });
+  it.each([
+    {},
+    { conversationId: null },
+    { conversationId: 1 },
+    { reason: "unknown" },
+    { reason: null },
+    { turnId: null },
+    { turnId: 42 },
+  ])("rejects malformed notice %j", (bad) => {
+    const msg = {
+      type: "chat.resync-required",
+      conversationId: "c1",
+      reason: "replay-limit",
+      ...bad,
+    };
+    if (Object.keys(bad).length === 0) delete (msg as { conversationId?: unknown }).conversationId;
+    expect(parseServerMessage(JSON.stringify(msg))).toBeNull();
+  });
+});
diff --git a/src/adapters/ws/logic.ts b/src/adapters/ws/logic.ts
index 0efcd90..abc0464 100644
--- a/src/adapters/ws/logic.ts
+++ b/src/adapters/ws/logic.ts
@@ -2,6 +2,7 @@ import type {
   ChatDeltaMessage,
   ChatErrorMessage,
   ChatQueuedMessage,
+  ChatResyncRequiredMessage,
   ConversationCompactedMessage,
   ConversationOpenMessage,
   ConversationStatusChangedMessage,
@@ -27,6 +28,7 @@ const VALID_SERVER_TYPES = new Set([
   "chat.delta",
   "chat.error",
   "chat.queued",
+  "chat.resync-required",
   "conversation.open",
   "conversation.statusChanged",
   "conversation.compacted",
@@ -113,6 +115,18 @@ export function parseServerMessage(data: string): WsServerMessage | null {
       if (typeof event.type !== "string") return null;
       return { type: "chat.delta", event: event as unknown as ChatDeltaMessage["event"] };
     }
+    case "chat.resync-required": {
+      if (typeof parsed.conversationId !== "string") return null;
+      if (parsed.turnId !== undefined && typeof parsed.turnId !== "string") return null;
+      if (parsed.reason !== "replay-limit" && parsed.reason !== "payload-limit") return null;
+      const msg: ChatResyncRequiredMessage = {
+        type: "chat.resync-required",
+        conversationId: parsed.conversationId,
+        reason: parsed.reason,
+        ...(parsed.turnId !== undefined ? { turnId: parsed.turnId } : {}),
+      };
+      return msg;
+    }
     case "chat.queued": {
       if (typeof parsed.conversationId !== "string") return null;
       if (typeof parsed.messageId !== "string") return null;