fix(server): Pi editor dialogs prefill the answer composer

apps/mobile/src/features/threads/QuestionAttachments.tsx

@@ -189,6 +189,8 @@ export function QuestionAttachments(props: {
       <TextInputWrapper onPaste={paste}>
         <TextInput
           value={props.value}
+          multiline={props.question.initialAnswer !== undefined}
+          submitBehavior={props.question.initialAnswer !== undefined ? "newline" : undefined}
           editable={!props.disabled}
           onChangeText={props.onChangeText}
           onFocus={() => props.onInputFocusChange?.(true)}

apps/mobile/src/lib/threadActivity.test.ts

@@ -2011,6 +2011,29 @@ const multiSelectQuestion = {
 } as const;
 
 describe("pending user input answers", () => {
+  it("preserves exact editor text, including a deliberately cleared answer", () => {
+    const question = { ...singleSelectQuestion, initialAnswer: "  Proposed message\n" };
+    expect(
+      buildPendingUserInputAnswers([question], {
+        runtime: { customAnswer: question.initialAnswer },
+      }),
+    ).toEqual({ runtime: question.initialAnswer });
+    expect(
+      buildPendingUserInputAnswers([question], {
+        runtime: { customAnswer: "  Edited message\n\n" },
+      }),
+    ).toEqual({ runtime: "  Edited message\n\n" });
+    expect(buildPendingUserInputAnswers([question], { runtime: { customAnswer: "" } })).toEqual({
+      runtime: "",
+    });
+    expect(buildPendingUserInputAnswers([question], { runtime: { customAnswer: " \n" } })).toEqual({
+      runtime: " \n",
+    });
+    expect(setPendingUserInputCustomAnswer(question, { selectedOptionValues: ["Go"] }, "")).toEqual(
+      { customAnswer: "" },
+    );
+  });
+
   it("replaces single-select options and toggles multi-select options", () => {
     expect(
       togglePendingUserInputOptionSelection(

apps/mobile/src/lib/threadActivity.ts

@@ -399,21 +399,25 @@ function resolvePendingUserInputAnswer(
 ): string | ReadonlyArray<string> | null {
   if (draft?.attachmentsBlocked) return null;
   const customAnswer =
-    question.allowCustomAnswer === false ? null : normalizeDraftAnswer(draft?.customAnswer);
-  if (customAnswer) {
+    question.allowCustomAnswer === false
+      ? null
+      : question.initialAnswer !== undefined
+        ? (draft?.customAnswer ?? null)
+        : normalizeDraftAnswer(draft?.customAnswer);
+  if (customAnswer !== null && customAnswer.length > 0) {
     return customAnswer;
   }
 
   const selectedOptionValues = normalizeSelectedOptionValues(question, draft?.selectedOptionValues);
   if (question.multiSelect) {
     return selectedOptionValues.length > 0
       ? selectedOptionValues
-      : question.allowCustomAnswer !== false && (draft?.attachmentCount ?? 0) > 0
-        ? ""
-        : null;
+      : (customAnswer ??
+          (question.allowCustomAnswer !== false && (draft?.attachmentCount ?? 0) > 0 ? "" : null));
   }
   return (
     selectedOptionValues[0] ??
+    customAnswer ??
     (question.allowCustomAnswer !== false && (draft?.attachmentCount ?? 0) > 0 ? "" : null)
   );
 }
@@ -1633,7 +1637,7 @@ export function setPendingUserInputCustomAnswer(
   }
 
   const selectedOptionValues =
-    customAnswer.trim().length > 0
+    question.initialAnswer !== undefined || customAnswer.trim().length > 0
       ? undefined
       : normalizeSelectedOptionValues(question, draft?.selectedOptionValues);
   return {

apps/mobile/src/state/use-selected-thread-requests.ts

@@ -18,6 +18,7 @@ import { type ProviderApprovalDecision, type RuntimeRequestId } from "@t3tools/c
 import {
   type PendingThreadRequests,
   type ThreadUserInputQuestion,
+  seedUserInputDraftAnswers,
 } from "@t3tools/client-runtime/state/thread-requests";
 import { AuthOrchestrationOperateScope } from "@t3tools/contracts";
 import { Atom } from "effect/reactivity";
@@ -104,6 +105,19 @@ export function useSelectedThreadRequests() {
   const activePendingApproval = activePendingApprovals[0] ?? null;
   const activePendingUserInputs = pendingRequests?.userInputs ?? EMPTY_PENDING_REQUESTS.userInputs;
   const activePendingUserInput = activePendingUserInputs[0] ?? null;
+  useEffect(() => {
+    if (!activePendingUserInput || !selectedThreadShell) return;
+    const requestKey = scopedRequestKey(
+      selectedThreadShell.environmentId,
+      activePendingUserInput.requestId,
+    );
+    const existing = appAtomRegistry.get(userInputDraftsByRequestKeyAtom);
+    const drafts = existing[requestKey] ?? {};
+    const seeded = seedUserInputDraftAnswers(activePendingUserInput.questions, drafts);
+    if (seeded !== drafts) {
+      appAtomRegistry.set(userInputDraftsByRequestKeyAtom, { ...existing, [requestKey]: seeded });
+    }
+  }, [activePendingUserInput, selectedThreadShell]);
   const questionServerConfigs = useServerConfigs();
   const attachmentDrafts = useAtomValue(composerDraftsAtom);
   const preparationCounts = useAtomValue(questionAttachmentPreparationAtom);

apps/server/src/mcp/toolkits/thread/tools.ts

@@ -141,6 +141,7 @@ const question = Schema.Struct({
   ),
   multiSelect: Schema.optional(Schema.Boolean),
   allowCustomAnswer: Schema.optional(Schema.Boolean),
+  initialAnswer: Schema.optional(Schema.String),
   required: Schema.optional(Schema.Boolean),
 });
 const pendingRequest = Schema.Struct({

apps/server/src/orchestration-v2/Adapters/PiAdapterV2.test.ts

@@ -1583,6 +1583,65 @@ describe("PiAdapterV2", () => {
     }).pipe(Effect.scoped, Effect.provide(layerTest)),
   );
 
+  it.effect("keeps the complete editor prefill editable and returns exact edited text", () =>
+    Effect.gen(function* () {
+      const fake = yield* makeFakePi;
+      const { runtime, takeEvent } = yield* openRuntime(fake);
+      yield* runtime.ensureThread({
+        threadId: THREAD_ID,
+        modelSelection: modelSelection("default"),
+        runtimePolicy,
+      });
+      const prefill = `  fix(server): retain full editor content\n\n${"detail\n".repeat(500)}  `;
+      yield* fake.emit({
+        type: "extension_ui_request",
+        id: "ui-editor",
+        method: "editor",
+        title: "Commit message",
+        prefill,
+      });
+      const event = yield* takeEvent(
+        (event) =>
+          event.type === "turn_item.updated" && event.turnItem.type === "user_input_request",
+      );
+      if (event.type !== "turn_item.updated" || event.turnItem.type !== "user_input_request")
+        return;
+      assert.equal(event.turnItem.questions[0]?.initialAnswer, prefill);
+      assert.deepEqual(event.turnItem.questions[0]?.options, []);
+      assert.equal(event.turnItem.questions[0]?.question, "Commit message");
+      const edited = "  fix(server): edited commit message\n\n";
+      yield* runtime.respondToRuntimeRequest({
+        requestId: event.turnItem.requestId,
+        answers: { "ui-editor": edited },
+      });
+      const response = yield* fake.takeRequest("extension_ui_response");
+      assert.equal(response["value"], edited);
+      assert.isUndefined(response["cancelled"]);
+      yield* fake.emit({
+        type: "extension_ui_request",
+        id: "ui-editor-cleared",
+        method: "editor",
+        title: "Commit message",
+        prefill,
+      });
+      const cleared = yield* takeEvent(
+        (event) =>
+          event.type === "turn_item.updated" &&
+          event.turnItem.type === "user_input_request" &&
+          event.turnItem.questions.some((question) => question.id === "ui-editor-cleared"),
+      );
+      if (cleared.type !== "turn_item.updated" || cleared.turnItem.type !== "user_input_request")
+        return;
+      yield* runtime.respondToRuntimeRequest({
+        requestId: cleared.turnItem.requestId,
+        answers: { "ui-editor-cleared": "" },
+      });
+      const emptyResponse = yield* fake.takeRequest("extension_ui_response");
+      assert.equal(emptyResponse["value"], "");
+      assert.isUndefined(emptyResponse["cancelled"]);
+    }).pipe(Effect.scoped, Effect.provide(layerTest)),
+  );
+
   it.effect("raises bridge edit confirmations as file-change approvals", () =>
     Effect.gen(function* () {
       const fake = yield* makeFakePi;

apps/server/src/orchestration-v2/Adapters/PiAdapterV2.ts

@@ -2912,25 +2912,21 @@ function piQuestion(
       ? event["options"]
           .filter((option): option is string => typeof option === "string")
           .map((option) => ({ label: option || "Empty value", description: option, value: option }))
-      : [
-          {
-            label: "Submit empty value",
-            description: "Send an empty string to the extension.",
-            value: "",
-          },
-        ];
-  // The user-input contract has no prefill field, so an editor dialog's
-  // prefill is surfaced inside the question text; without it the user would
-  // edit blind against content they cannot see.
-  const prefill = method === "editor" ? recordString(event, "prefill") : undefined;
+      : method === "editor"
+        ? []
+        : [
+            {
+              label: "Submit empty value",
+              description: "Send an empty string to the extension.",
+              value: "",
+            },
+          ];
   const question = recordString(event, "message") ?? recordString(event, "placeholder") ?? title;
   return {
     id: questionId,
     header: title,
-    question:
-      prefill === undefined || prefill.length === 0
-        ? question
-        : `${question}\n\nCurrent value:\n${prefill.slice(0, 2_000)}`,
+    question,
+    ...(method === "editor" ? { initialAnswer: recordString(event, "prefill") ?? "" } : {}),
     options,
   };
 }

apps/web/src/components/ChatView.tsx

@@ -217,6 +217,7 @@ import {
   togglePendingUserInputOptionSelection,
   type PendingUserInputDraftAnswer,
 } from "../pendingUserInput";
+import { seedUserInputDraftAnswers } from "@t3tools/client-runtime/state/thread-requests";
 import { useUiStateStore } from "../uiStateStore";
 import { useWorkspaceMutationRefresh } from "../hooks/useWorkspaceMutationRefresh";
 import {
@@ -3312,6 +3313,19 @@ export default function ChatView(props: ChatViewProps) {
     activeThreadId,
     activePendingUserInput?.requestId,
   ]);
+  const activePendingAnswerDrafts =
+    pendingUserInputAnswersByRequestId[activePendingRequestKey] ?? EMPTY_PENDING_USER_INPUT_ANSWERS;
+  if (
+    activePendingUserInput &&
+    seedUserInputDraftAnswers(activePendingUserInput.questions, activePendingAnswerDrafts) !==
+      activePendingAnswerDrafts
+  ) {
+    setPendingUserInputAnswersByRequestId((existing) => {
+      const drafts = existing[activePendingRequestKey] ?? EMPTY_PENDING_USER_INPUT_ANSWERS;
+      const seeded = seedUserInputDraftAnswers(activePendingUserInput.questions, drafts);
+      return seeded === drafts ? existing : { ...existing, [activePendingRequestKey]: seeded };
+    });
+  }
   const pendingQuestionDraftKeys = useMemo(
     () =>
       activeThreadId
@@ -10294,6 +10308,7 @@ export default function ChatView(props: ChatViewProps) {
           [questionId]: setPendingUserInputCustomAnswer(
             existing[activePendingRequestKey]?.[questionId],
             value,
+            question,
           ),
         },
       }));

apps/web/src/components/ComposerPromptEditor.tsx

@@ -9,8 +9,8 @@ export type {
 
 /**
  * The composer editor. Tiptap in both modes: the `richTextEnabled` setting
- * toggles Markdown styling, never the engine. Plain mode renders every
- * marker as a literal character and serializes byte-identically.
+ * toggles Markdown styling, never the engine. Plain mode keeps Markdown
+ * markers literal; `literalText` also preserves context-token sources as text.
  */
 export function ComposerPromptEditor(props: ComposerPromptEditorProps) {
   return <ComposerPromptEditorTiptap {...props} />;