diff --git a/apps/web/src/components/ChatView.tsx b/apps/web/src/components/ChatView.tsx
index 79d393fc8d1f180c147e6b7053c13f61f5fbd66c..667eb0e11f6c6d6b71959ff7f50a321baebb6552 100644
--- a/apps/web/src/components/ChatView.tsx
+++ b/apps/web/src/components/ChatView.tsx
@@ -148,6 +148,7 @@ import {
 } from "./chat/timelineScrollAnchoring";
 import {
   buildPendingUserInputAnswers,
+  carryDisplacedCustomAnswerIntoPrompt,
   derivePendingUserInputProgress,
   setPendingUserInputCustomAnswer,
   togglePendingUserInputOptionSelection,
@@ -8810,6 +8811,16 @@ export default function ChatView(props: ChatViewProps) {
       if (!activePendingUserInput) {
         return;
       }
+      // The option replaces the custom answer. Anything typed there is the
+      // user's text, so it goes back to the thread draft instead of vanishing.
+      const displacedAnswer =
+        pendingUserInputAnswersByRequestId[activePendingRequestKey]?.[questionId]?.customAnswer;
+      const currentPrompt =
+        useComposerDraftStore.getState().getComposerDraft(composerDraftTarget)?.prompt ?? "";
+      const nextPrompt = carryDisplacedCustomAnswerIntoPrompt(currentPrompt, displacedAnswer);
+      if (nextPrompt !== currentPrompt) {
+        setComposerDraftPrompt(composerDraftTarget, nextPrompt);
+      }
       setPendingUserInputAnswersByRequestId((existing) => {
         const question =
           (activePendingProgress?.activeQuestion?.id === questionId
@@ -8839,7 +8850,10 @@ export default function ChatView(props: ChatViewProps) {
       activePendingProgress?.activeQuestion,
       activePendingUserInput,
       activePendingRequestKey,
+      composerDraftTarget,
       composerRef,
+      pendingUserInputAnswersByRequestId,
+      setComposerDraftPrompt,
     ],
   );
 
diff --git a/apps/web/src/components/chat/ChatComposer.tsx b/apps/web/src/components/chat/ChatComposer.tsx
index 8f91f08c709328f7113b99f81fdbe31e440e5776..255f61a0c752014dc8a16358f5c567829a01326e 100644
--- a/apps/web/src/components/chat/ChatComposer.tsx
+++ b/apps/web/src/components/chat/ChatComposer.tsx
@@ -72,6 +72,7 @@ import {
   type ComposerSubmissionIntent,
   type ComposerTrigger,
   collapseExpandedComposerCursor,
+  composerStateAtPromptEnd,
   composerSubmissionIntentForEnter,
   detectComposerTrigger,
   expandCollapsedComposerCursor,
@@ -3080,6 +3081,15 @@ export const ChatComposer = memo(function ChatComposer(props: ChatComposerProps)
   useEffect(() => {
     const nextCustomAnswer = activePendingProgress?.customAnswer;
     if (typeof nextCustomAnswer !== "string") {
+      // The question is gone and the editor shows the thread draft again. The
+      // ref still holds the last answer text, and Send reads the ref. Place
+      // the caret at the end so the next keystroke appends.
+      if (lastSyncedPendingInputRef.current !== null) {
+        promptRef.current = prompt;
+        const { cursor, trigger } = composerStateAtPromptEnd(prompt);
+        setComposerCursor(cursor);
+        setComposerTrigger(trigger);
+      }
       lastSyncedPendingInputRef.current = null;
       return;
     }
@@ -3101,19 +3111,15 @@ export const ChatComposer = memo(function ChatComposer(props: ChatComposerProps)
     }
 
     promptRef.current = nextCustomAnswer;
-    const nextCursor = collapseExpandedComposerCursor(nextCustomAnswer, nextCustomAnswer.length);
-    setComposerCursor(nextCursor);
-    setComposerTrigger(
-      detectComposerTrigger(
-        nextCustomAnswer,
-        expandCollapsedComposerCursor(nextCustomAnswer, nextCursor),
-      ),
-    );
+    const { cursor, trigger } = composerStateAtPromptEnd(nextCustomAnswer);
+    setComposerCursor(cursor);
+    setComposerTrigger(trigger);
     setComposerHighlightedItemId(null);
   }, [
     activePendingProgress?.customAnswer,
     activePendingProgress?.activeQuestion?.id,
     activePendingUserInput?.requestId,
+    prompt,
     promptRef,
   ]);
 
diff --git a/apps/web/src/composer-logic.test.ts b/apps/web/src/composer-logic.test.ts
index d4509516cba7e0fea571dc26ca42e5b5d5ef0e2d..83f143a546fd8c386eb2c71b562f4d0254871649 100644
--- a/apps/web/src/composer-logic.test.ts
+++ b/apps/web/src/composer-logic.test.ts
@@ -10,6 +10,7 @@ import { describe, expect, it } from "vite-plus/test";
 import {
   clampCollapsedComposerCursor,
   collapseExpandedComposerCursor,
+  composerStateAtPromptEnd,
   composerSubmissionIntentForEnter,
   detectComposerTrigger,
   expandCollapsedComposerCursor,
@@ -18,6 +19,7 @@ import {
   parseStandaloneComposerSlashCommand,
   replaceTextRange,
 } from "./composer-logic";
+import { carryDisplacedCustomAnswerIntoPrompt } from "./pendingUserInput";
 import { formatTerminalContextReference } from "./lib/terminalContext";
 
 const terminalReference = formatTerminalContextReference({
@@ -482,6 +484,34 @@ describe("expandCollapsedComposerCursor", () => {
   });
 });
 
+describe("composerStateAtPromptEnd", () => {
+  it("puts the caret at the end of a restored parked draft", () => {
+    const prompt = carryDisplacedCustomAnswerIntoPrompt("first half\n", "second half");
+
+    expect(composerStateAtPromptEnd(prompt)).toEqual({
+      cursor: prompt.length,
+      trigger: null,
+    });
+  });
+
+  it("collapses mention chips so the next keystroke lands after the draft", () => {
+    const prompt = carryDisplacedCustomAnswerIntoPrompt("", "see @AGENTS.md please");
+
+    expect(composerStateAtPromptEnd(prompt).cursor).toBe("see ".length + 1 + " please".length);
+    expect(composerStateAtPromptEnd(prompt).cursor).not.toBe(0);
+    expect(composerStateAtPromptEnd(prompt).cursor).not.toBe(prompt.length);
+  });
+
+  it("keeps a trailing mention trigger when the restored draft ends with @", () => {
+    const prompt = "look at @";
+
+    expect(composerStateAtPromptEnd(prompt)).toEqual({
+      cursor: prompt.length,
+      trigger: { kind: "path", query: "", rangeStart: "look at ".length, rangeEnd: prompt.length },
+    });
+  });
+});
+
 describe("collapseExpandedComposerCursor", () => {
   it("keeps cursor unchanged when no mention segment is present", () => {
     expect(collapseExpandedComposerCursor("plain text", 5)).toBe(5);
diff --git a/apps/web/src/composer-logic.ts b/apps/web/src/composer-logic.ts
index a2ed12b86b9ebe638a260684aa9c2ae46e03f0c7..ff638a6d2e46c63ef7691d627a5dfc039d96f987 100644
--- a/apps/web/src/composer-logic.ts
+++ b/apps/web/src/composer-logic.ts
@@ -265,6 +265,18 @@ export function detectComposerTrigger(text: string, cursorInput: number): Compos
   };
 }
 
+/** Caret and trigger after replacing composer text and continuing at the end. */
+export function composerStateAtPromptEnd(text: string): {
+  cursor: number;
+  trigger: ComposerTrigger | null;
+} {
+  const cursor = collapseExpandedComposerCursor(text, text.length);
+  return {
+    cursor,
+    trigger: detectComposerTrigger(text, expandCollapsedComposerCursor(text, cursor)),
+  };
+}
+
 export function parseStandaloneComposerSlashCommand(
   text: string,
 ): Exclude<ComposerSlashCommand, "model"> | null {
diff --git a/apps/web/src/pendingUserInput.test.ts b/apps/web/src/pendingUserInput.test.ts
index f2f093a5c8268e05f8213b62c5c3cabadca10e40..350087c3aaffcd10061c2b726774d9641aaacdf8 100644
--- a/apps/web/src/pendingUserInput.test.ts
+++ b/apps/web/src/pendingUserInput.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from "vite-plus/test";
 
 import {
   buildPendingUserInputAnswers,
+  carryDisplacedCustomAnswerIntoPrompt,
   countAnsweredPendingUserInputQuestions,
   derivePendingUserInputProgress,
   resolvePendingUserInputAnswer,
@@ -321,3 +322,22 @@ it("accepts attachment-only answers after every upload finishes", () => {
     }),
   ).toBeNull();
 });
+
+describe("carryDisplacedCustomAnswerIntoPrompt", () => {
+  it("keeps the thread draft when nothing was typed into the answer", () => {
+    expect(carryDisplacedCustomAnswerIntoPrompt("draft", undefined)).toBe("draft");
+    expect(carryDisplacedCustomAnswerIntoPrompt("draft", "   ")).toBe("draft");
+  });
+
+  it("moves the typed answer into an empty thread draft", () => {
+    expect(carryDisplacedCustomAnswerIntoPrompt("", "also rename the flag ")).toBe(
+      "also rename the flag",
+    );
+  });
+
+  it("appends the typed answer after an existing thread draft", () => {
+    expect(carryDisplacedCustomAnswerIntoPrompt("first half\n", "second half")).toBe(
+      "first half\n\nsecond half",
+    );
+  });
+});
diff --git a/apps/web/src/pendingUserInput.ts b/apps/web/src/pendingUserInput.ts
index 5ac004649a2715f4659486ac6e229417dfb83f2d..5d22e56105aa632b45d4dbf43d072f9bfddbff79 100644
--- a/apps/web/src/pendingUserInput.ts
+++ b/apps/web/src/pendingUserInput.ts
@@ -82,6 +82,28 @@ export function setPendingUserInputCustomAnswer(
   };
 }
 
+const DISPLACED_ANSWER_SEPARATOR = "\n\n";
+
+/**
+ * Selecting an option replaces the custom answer, because a non-empty custom
+ * answer outranks selected options in `resolvePendingUserInputAnswer`. Text the
+ * user typed into the answer field must not vanish on that click: it moves back
+ * into the thread draft, after whatever was already waiting there.
+ */
+export function carryDisplacedCustomAnswerIntoPrompt(
+  prompt: string,
+  customAnswer: string | undefined,
+): string {
+  const displaced = customAnswer?.trim() ?? "";
+  if (displaced.length === 0) {
+    return prompt;
+  }
+  if (prompt.trim().length === 0) {
+    return displaced;
+  }
+  return `${prompt.trimEnd()}${DISPLACED_ANSWER_SEPARATOR}${displaced}`;
+}
+
 export function togglePendingUserInputOptionSelection(
   question: UserInputQuestion,
   draft: PendingUserInputDraftAnswer | undefined,