diff --git a/agent-chat/src/components/Chat.tsx b/agent-chat/src/components/Chat.tsx
index 2922ad2b9f38..4a4d9c7cf851 100644
--- a/agent-chat/src/components/Chat.tsx
+++ b/agent-chat/src/components/Chat.tsx
@@ -3,7 +3,7 @@ import { useEffect, useLayoutEffect, useMemo, useRef, useState, type RefObject }
 import { useCtx } from "../context";
 import { agentChatText } from "../i18n";
 import { readStoredProviderOptions, persistOptionsSnapshot, updateStoredProviderOption } from "../options-store";
-import { routedToTranscript, transcriptComposerLocked, type OptionValue, type SessionOption } from "../session";
+import { composerDraftKey, routedToTranscript, transcriptComposerLocked, type OptionValue, type SessionOption } from "../session";
 import { ArrowUp } from "./icons";
 import { isCtrlJ, insertNewlineAtCaret, useCommandMenu } from "./CommandMenu";
 import { optionAcceptsValue, optionsForSelectedModel } from "./options";
@@ -57,7 +57,7 @@ function useStickToBottom(scrollRef: RefObject<HTMLDivElement | null>, stickRef:
 
 export function Chat() {
   const { ready, connectionEpoch, providers, capabilities, providerOptions, session, routing, blocks, options, actions, commands, filesByCwd, fileDiffs, fileDiffErrors, ctrlJ, forkPending, handoffPending, reply, stop, focusTerminal, setOption, fork, handoff, compose, requestProviderOptions, requestProviderCommands, requestFiles, requestFileDiff } = useCtx();
-  const [text, setText] = useState("");
+  const [text, setText] = useState(() => draftStorage.getItem(composerDraftKey) || "");
   const [openOptionId, setOpenOptionId] = useState<string | null>(null);
   const [helpOpen, setHelpOpen] = useState(false);
   const taRef = useAutoGrow(text, 200);
@@ -84,6 +84,10 @@ export function Chat() {
   useProviderCatalogs(ready, connectionEpoch, providers, session?.provider ?? "", catalogCwd, requestProviderOptions, requestProviderCommands);
   useFileCatalog(ready, connectionEpoch, catalogCwd, requestFiles);
   useStickToBottom(scrollRef, stickRef, blocks, running);
+  useEffect(() => {
+    if (text) draftStorage.setItem(composerDraftKey, text);
+    else draftStorage.removeItem(composerDraftKey);
+  }, [text]);
   useKeymap({
     options: resolvedOptions,
     setOption,
diff --git a/agent-chat/src/session.ts b/agent-chat/src/session.ts
index 32f3aec7e54b..4e5d67da5692 100644
--- a/agent-chat/src/session.ts
+++ b/agent-chat/src/session.ts
@@ -329,7 +329,29 @@ function newClientRequestId(prefix: string): string {
 }
 
 export function restoreComposerDraft(storage: Pick<Storage, "setItem">, prompt: string) {
-  storage.setItem(composerDraftKey, prompt);
+  try { storage.setItem(composerDraftKey, prompt); } catch {
+    // Draft recovery is best effort when browser storage is unavailable.
+  }
+}
+
+export function readComposerDraft(storage: Pick<Storage, "getItem">): string {
+  try {
+    return storage.getItem(composerDraftKey) || "";
+  } catch {
+    return "";
+  }
+}
+
+export function writeComposerDraft(
+  storage: Pick<Storage, "setItem" | "removeItem">,
+  draft: string,
+) {
+  try {
+    if (draft) storage.setItem(composerDraftKey, draft);
+    else storage.removeItem(composerDraftKey);
+  } catch {
+    // Private browsing and embedded Cloud contexts can deny session storage.
+  }
 }
 
 // An echo matches anywhere in the queue: one that never lands (a failed send)
diff --git a/agent-chat/test/session.test.ts b/agent-chat/test/session.test.ts
index f764be7c064d..156fb4e666f9 100644
--- a/agent-chat/test/session.test.ts
+++ b/agent-chat/test/session.test.ts
@@ -3,7 +3,7 @@ Object.defineProperty(globalThis, "location", {
   value: { pathname: "/" },
 });
 
-const { composerDraftKey, consumeOptimisticUserEcho, foldEvent, latestRouting, restoreComposerDraft, shouldAcceptSessionActionResponse, transcriptComposerLocked } = await import("../src/session");
+const { composerDraftKey, consumeOptimisticUserEcho, foldEvent, latestRouting, readComposerDraft, restoreComposerDraft, shouldAcceptSessionActionResponse, transcriptComposerLocked, writeComposerDraft } = await import("../src/session");
 const { latestRouteStatus, normalizeRouteStatus, routeHealthForPhase } = await import("../route-status");
 const { draftStorage } = await import("../src/browser-storage");
 
@@ -35,6 +35,20 @@ try {
   else Reflect.deleteProperty(globalThis, "sessionStorage");
 }
 
+const draftValues: Record<string, string> = {};
+const draftFixture = {
+  getItem: (key: string) => draftValues[key] ?? null,
+  setItem: (key: string, value: string) => { draftValues[key] = value; },
+  removeItem: (key: string) => { delete draftValues[key]; },
+};
+writeComposerDraft(draftFixture, "typed while Cloud was reconnecting");
+if (readComposerDraft(draftFixture) !== "typed while Cloud was reconnecting") throw new Error("live draft was not recoverable");
+writeComposerDraft(draftFixture, "");
+if (readComposerDraft(draftFixture) !== "") throw new Error("clearing draft did not remove it");
+const unavailableStorage = { getItem() { throw new Error("storage unavailable"); }, setItem() { throw new Error("storage unavailable"); }, removeItem() { throw new Error("storage unavailable"); } };
+writeComposerDraft(unavailableStorage, "still usable");
+if (readComposerDraft(unavailableStorage) !== "") throw new Error("storage failures should not break draft access");
+
 const repeated = [
   { kind: "user" as const, text: "same" },
   { kind: "user" as const, text: "same" },