feat(mobile): wrap shared links and text in a saved prompt template

apps/mobile/src/features/settings/SettingsFollowUpRouteScreen.tsx

@@ -10,6 +10,7 @@ import { mobilePreferencesAtom, updateMobilePreferencesAtom } from "../../state/
 import { ListChoiceRow as SettingsChoiceRow } from "../../components/ui/ListChoiceRow";
 import { SettingsSection } from "./components/SettingsSection";
 import { SettingsScreen } from "./components/SettingsScreen";
+import { ShareTemplatesSection } from "./ShareTemplatesSection";
 
 const FOLLOW_UP_OPTIONS: ReadonlyArray<{
   readonly behavior: FollowUpBehavior;
@@ -62,6 +63,7 @@ export function SettingsFollowUpRouteScreen() {
         Long-press the send button to use the other option for a single message. With a hardware
         keyboard, hold Command while sending.
       </Text>
+      <ShareTemplatesSection />
     </ScrollView>
   );
 

apps/mobile/src/features/settings/ShareTemplatesSection.tsx

@@ -0,0 +1,91 @@
+import { useAtomSet, useAtomValue } from "@effect/atom-react";
+import { AsyncResult } from "effect/reactivity";
+import { useState } from "react";
+import { TextInput, View } from "react-native";
+
+import * as Dialog from "../../components/ui/Dialog";
+import { IconButton } from "../../components/ui/IconButton";
+import { ListActionRow } from "../../components/ui/ListActionRow";
+import { uuidv4 } from "../../lib/uuid";
+import { mobilePreferencesAtom, updateMobilePreferencesAtom } from "../../state/preferences";
+import { SHARE_TEMPLATE_PLACEHOLDER, type ShareTemplate } from "../sharing/share-templates";
+import { SettingsSection } from "./components/SettingsSection";
+
+export function ShareTemplatesSection() {
+  const preferencesResult = useAtomValue(mobilePreferencesAtom);
+  const savePreferences = useAtomSet(updateMobilePreferencesAtom);
+  const [addedTemplateId, setAddedTemplateId] = useState<string | null>(null);
+  const templates = AsyncResult.isSuccess(preferencesResult)
+    ? (preferencesResult.value.shareTemplates ?? [])
+    : null;
+
+  const updateTemplates = (
+    transform: (templates: ReadonlyArray<ShareTemplate>) => ReadonlyArray<ShareTemplate>,
+  ) =>
+    savePreferences({
+      transform: (current) => ({ shareTemplates: transform(current.shareTemplates ?? []) }),
+    });
+  const addTemplate = () => {
+    const id = uuidv4();
+    setAddedTemplateId(id);
+    updateTemplates((current) => [...current, { id, prompt: "" }]);
+  };
+  const removeTemplate = (template: ShareTemplate) => {
+    const remove = () =>
+      updateTemplates((current) => current.filter(({ id }) => id !== template.id));
+    if (!template.prompt.trim()) {
+      remove();
+      return;
+    }
+    Dialog.confirm({
+      title: "Delete this template?",
+      confirmText: "Delete",
+      destructive: true,
+      onConfirm: remove,
+    });
+  };
+
+  return (
+    <SettingsSection
+      title="Share templates"
+      footer={`When you share to T3 Code from another app, choose a template to wrap what you shared. Write ${SHARE_TEMPLATE_PLACEHOLDER} where the shared text goes, or it goes at the end.`}
+    >
+      {(templates ?? []).map((template) => (
+        <View
+          key={template.id}
+          className="flex-row items-start gap-1 border-b border-border-subtle py-1 pl-4"
+        >
+          {/* Uncontrolled so saving each keystroke never moves the cursor. */}
+          <TextInput
+            accessibilityLabel="Template prompt"
+            className="min-h-12 flex-1 py-2 text-base text-foreground"
+            placeholderTextColorClassName="accent-foreground-muted"
+            placeholder={`Review this for bugs:\n\n${SHARE_TEMPLATE_PLACEHOLDER}`}
+            multiline
+            autoFocus={template.id === addedTemplateId}
+            defaultValue={template.prompt}
+            onChangeText={(prompt) =>
+              updateTemplates((current) =>
+                current.map((candidate) =>
+                  candidate.id === template.id ? { ...candidate, prompt } : candidate,
+                ),
+              )
+            }
+          />
+          <IconButton
+            accessibilityLabel="Delete template"
+            icon="trash"
+            tintColorClassName="accent-danger-foreground"
+            onPress={() => removeTemplate(template)}
+          />
+        </View>
+      ))}
+      <ListActionRow
+        icon="plus"
+        label="Add template"
+        disabled={templates === null}
+        onPress={addTemplate}
+      />
+    </SettingsSection>
+  );
+}

apps/mobile/src/features/settings/settings-search.ts

@@ -56,7 +56,14 @@ const SETTINGS_SEARCH_TERMS = {
     "auto-resume",
     "thread behavior",
   ],
-  SettingsFollowUp: ["follow-ups", "queue", "steer", "while the agent is running"],
+  SettingsFollowUp: [
+    "follow-ups",
+    "queue",
+    "steer",
+    "while the agent is running",
+    "share templates",
+    "share sheet",
+  ],
   SettingsArchive: ["archive", "archived", "restore", "unarchive"],
   SettingsProviderAccounts: [
     "provider accounts",

apps/mobile/src/features/sharing/IncomingShareProvider.tsx

@@ -160,6 +160,7 @@ const incomingShareInbox = new IncomingShareInbox({
         ? await resolvedPayloadsForFiles()
         : [];
     const draft = await buildIncomingShareDraft({
+      attachmentIdPrefix: Crypto.randomUUID(),
       payloads,
       resolvedPayloads,
       fileReader: {

apps/mobile/src/features/sharing/incoming-share-model.test.ts

@@ -7,6 +7,7 @@ import type { ResolvedSharePayload, SharePayload } from "expo-sharing";
 
 import {
   buildIncomingShareDraft,
+  decodeIncomingShareDraft,
   hasIncomingShareContent,
   isShareFileUriUnderOwnedRoots,
   selectIncomingShareAttachments,
@@ -20,11 +21,17 @@ describe("incoming native shares", () => {
       value: "file:///shared/Screenshot.png",
       mimeType: "image/png",
     };
+    const file: SharePayload = {
+      shareType: "file",
+      value: "file:///shared/report.pdf",
+      mimeType: "application/pdf",
+    };
     const payloads: SharePayload[] = [
       { shareType: "text", value: "Please explain this error" },
       { shareType: "url", value: "https://example.com/issue/1" },
       { shareType: "text", value: "Please explain this error" },
       image,
+      file,
     ];
     const resolvedImage: ResolvedSharePayload = {
       ...image,
@@ -36,19 +43,38 @@ describe("incoming native shares", () => {
     };
     const removeOwnedFile = vi.fn(() => Promise.resolve());
 
-    const result = await buildIncomingShareDraft({
-      id: "share-1",
-      createdAt: "2026-07-15T10:00:00.000Z",
-      payloads,
-      resolvedPayloads: [resolvedImage],
-      fileReader: {
-        readBase64: async () => "YWJj",
-        removeOwnedFile,
-      },
-    });
+    const build = (attachmentIdPrefix: string) =>
+      buildIncomingShareDraft({
+        attachmentIdPrefix,
+        id: "share-1",
+        createdAt: "2026-07-15T10:00:00.000Z",
+        payloads,
+        resolvedPayloads: [
+          resolvedImage,
+          {
+            ...file,
+            contentUri: file.value,
+            contentType: "file",
+            contentMimeType: "application/pdf",
+            contentSize: 3,
+            originalName: "report.pdf",
+          },
+        ],
+        fileReader: {
+          readBase64: async () => "YWJj",
+          removeOwnedFile,
+        },
+      });
+
+    const result = await build("share-1");
+    const repeated = await build("second-handoff");
+    expect(
+      new Set([...result.attachments, ...repeated.attachments].map((attachment) => attachment.id))
+        .size,
+    ).toBe(4);
 
     expect(result).toEqual({
-      schemaVersion: 1,
+      schemaVersion: 2,
       id: "share-1",
       createdAt: "2026-07-15T10:00:00.000Z",
       text: "Please explain this error\n\nhttps://example.com/issue/1",
@@ -62,9 +88,22 @@ describe("incoming native shares", () => {
           dataUrl: "data:image/png;base64,YWJj",
           previewUri: "data:image/png;base64,YWJj",
         },
+        {
+          id: "share-1:file:4",
+          type: "file",
+          name: "report.pdf",
+          mimeType: "application/pdf",
+          sizeBytes: 3,
+          fileUri: "file:///shared/report.pdf",
+        },
       ],
       warnings: [],
     });
+    expect(decodeIncomingShareDraft(result)).toEqual(result);
+    expect(decodeIncomingShareDraft({ ...result, schemaVersion: 1 })).toEqual({
+      ...result,
+      schemaVersion: 1,
+    });
     expect(removeOwnedFile).toHaveBeenCalledWith(image.value);
     expect(hasIncomingShareContent(result)).toBe(true);
   });
@@ -79,6 +118,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(() => Promise.resolve());
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-2",
       id: "share-2",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [image],
@@ -113,6 +153,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async (_uri: string) => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-report",
       id: "share-report",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [file],
@@ -155,6 +196,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async () => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-video",
       id: "share-video",
       createdAt: "2026-08-30T10:00:00.000Z",
       payloads: [{ ...video, shareType: "video" }],
@@ -200,6 +242,7 @@ describe("incoming native shares", () => {
     };
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-empty",
       id: "share-empty",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [file],
@@ -225,6 +268,7 @@ describe("incoming native shares", () => {
     const readSize = vi.fn(async (uri: string) => (uri.startsWith("content:") ? null : 42));
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-android-report",
       id: "share-android-report",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [file],
@@ -263,6 +307,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async (_uri: string) => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-empty-copy",
       id: "share-empty-copy",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [file],
@@ -285,6 +330,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async () => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-no-copy",
       id: "share-no-copy",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [{ shareType: "file", value: sourceUri, mimeType: "application/pdf" }],
@@ -307,6 +353,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async (_uri: string) => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-copy",
       id: "share-copy",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads: [{ shareType: "file", value: payloadUri, mimeType: "application/pdf" }],
@@ -389,6 +436,7 @@ describe("incoming native shares", () => {
     const readBase64 = vi.fn(async () => "YWJj");
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-3",
       id: "share-3",
       createdAt: "2026-07-15T10:00:00.000Z",
       payloads,
@@ -434,6 +482,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async () => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-duplicates",
       id: "share-duplicates",
       createdAt: "2026-07-16T08:00:00.000Z",
       payloads: [duplicate, duplicate],
@@ -461,6 +510,7 @@ describe("incoming native shares", () => {
     };
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-cleanup-failure",
       id: "share-cleanup-failure",
       createdAt: "2026-07-16T08:00:00.000Z",
       payloads: [image],
@@ -487,6 +537,7 @@ describe("incoming native shares", () => {
     const removeOwnedFile = vi.fn(async (_uri: string) => undefined);
 
     const result = await buildIncomingShareDraft({
+      attachmentIdPrefix: "share-persist-leak",
       id: "share-persist-leak",
       createdAt: "2026-07-16T08:00:00.000Z",
       payloads: [file],

apps/mobile/src/features/sharing/incoming-share-model.ts

@@ -17,7 +17,7 @@ import type { DraftComposerAttachment } from "../../lib/composerImages";
 import { estimateBase64ByteSize } from "../../lib/base64";
 
 export interface IncomingShareDraft {
-  readonly schemaVersion: 1;
+  readonly schemaVersion: 1 | 2;
   readonly id: string;
   readonly createdAt: string;
   readonly destination?: IncomingShareDestination;
@@ -37,7 +37,7 @@ const IncomingShareDestinationSchema = Schema.Struct({
 });
 
 export const IncomingShareDraftSchema = Schema.Struct({
-  schemaVersion: Schema.Literal(1),
+  schemaVersion: Schema.Literals([1, 2]),
   id: Schema.String,
   createdAt: Schema.String,
   destination: Schema.optional(IncomingShareDestinationSchema),
@@ -232,6 +232,7 @@ export async function buildIncomingShareDraft(input: {
   readonly resolvedPayloads: ReadonlyArray<ResolvedSharePayload>;
   readonly fileReader: IncomingShareFileReader;
   readonly id: string;
+  readonly attachmentIdPrefix: string;
   readonly createdAt: string;
 }): Promise<IncomingShareDraft> {
   const attachments: DraftComposerAttachment[] = [];
@@ -332,7 +333,7 @@ export async function buildIncomingShareDraft(input: {
           }
         }
         attachments.push({
-          id: `${input.id}:file:${index}`,
+          id: `${input.attachmentIdPrefix}:file:${index}`,
           type: "file",
           name,
           mimeType,
@@ -397,7 +398,7 @@ export async function buildIncomingShareDraft(input: {
       }
       const dataUrl = `data:${mimeType};base64,${base64}`;
       attachments.push({
-        id: `${input.id}:image:${index}`,
+        id: `${input.attachmentIdPrefix}:image:${index}`,
         type: "image",
         name: resolved?.originalName ?? fallbackName(uri, index, mimeType),
         mimeType,
@@ -414,7 +415,7 @@ export async function buildIncomingShareDraft(input: {
   }
 
   return {
-    schemaVersion: 1,
+    schemaVersion: 2,
     id: input.id,
     createdAt: input.createdAt,
     text: sharedText(input.payloads),