fix(web): seeded models yield to started thread selections

apps/web/src/components/ChatView.logic.ts

@@ -73,6 +73,7 @@ import {
   type DraftThreadState,
 } from "../composerDraftStore";
 import * as Schema from "effect/Schema";
+import { threadHasStarted } from "../lib/chatThreadActions";
 import { appAtomRegistry } from "../rpc/atomRegistry";
 import { environmentThreadDetails } from "../state/threads";
 import {
@@ -825,10 +826,6 @@ export function recallCheckoutIsRepo(
     : sessionCheckoutIsRepo.get(checkoutIsRepoKey(environmentId, cwd));
 }
 
-function threadHasStarted(thread: Thread | null | undefined): boolean {
-  return Boolean(thread && (thread.latestRun !== null || thread.itemCount > 0 || thread.runtime));
-}
-
 // Imported history lacks a session until its first prompt; resolve its instance before locking the driver.
 export function deriveLockedProvider(input: {
   thread: Thread | null | undefined;

apps/web/src/components/ChatView.tsx

@@ -226,6 +226,7 @@ import { useNewThreadHandler } from "../hooks/useHandleNewThread";
 import { useOpenPanelPullRequestUrl } from "../hooks/useOpenPanelPullRequestUrl";
 import { isPreviewFocused } from "../lib/previewFocus";
 import { getTerminalFocusOwner } from "../lib/terminalFocus";
+import { draftModelSelectionApplies, threadHasStarted } from "../lib/chatThreadActions";
 import {
   deriveLogicalProjectKeyFromSettings,
   selectProjectGroupingSettings,
@@ -608,15 +609,15 @@ export default function ChatView(props: ChatViewProps) {
   const composerActiveProvider = useComposerDraftStore(
     (store) => store.getComposerDraft(composerDraftTarget)?.activeProvider ?? null,
   );
+  const composerModelSelectionExplicit = useComposerDraftStore(
+    (store) => store.getComposerDraft(composerDraftTarget)?.modelSelectionExplicit === true,
+  );
   const composerSelectedModelSelection = useComposerDraftStore((store) => {
     const draft = store.getComposerDraft(composerDraftTarget);
     return draft?.activeProvider
       ? (draft.modelSelectionByProvider[draft.activeProvider] ?? null)
       : null;
   });
-  const composerModelSelectionExplicit = useComposerDraftStore(
-    (store) => store.getComposerDraft(composerDraftTarget)?.modelSelectionExplicit === true,
-  );
   const composerHasAttachments = useComposerDraftStore((store) => {
     const draft = store.getComposerDraft(composerDraftTarget);
     return (draft?.images.length ?? 0) > 0 || (draft?.files.length ?? 0) > 0;
@@ -1264,7 +1265,11 @@ export default function ChatView(props: ChatViewProps) {
       : providersByEnvironment.get(providerEnvironmentId)) ?? EMPTY_PROVIDERS,
     gitCwd,
   );
-  const selectedProviderByThreadId = composerActiveProvider ?? null;
+  const composerModelSelectionApplies = draftModelSelectionApplies(
+    { modelSelectionExplicit: composerModelSelectionExplicit },
+    threadHasStarted(activeThread),
+  );
+  const selectedProviderByThreadId = composerModelSelectionApplies ? composerActiveProvider : null;
   const threadProvider =
     activeThread?.modelSelection.instanceId ??
     activeProjectDefaultModelSelection?.instanceId ??
@@ -2480,7 +2485,9 @@ export default function ChatView(props: ChatViewProps) {
       item.type === "user_message" &&
       (item.text.trim().toLowerCase() !== "/compact" || item.attachments.length > 0),
   );
-  const pendingHandoffSelection = composerSelectedModelSelection ?? activeThread?.modelSelection;
+  const pendingHandoffSelection =
+    (composerModelSelectionApplies ? composerSelectedModelSelection : null) ??
+    activeThread?.modelSelection;
   const pendingHandoffSelectionUsable = providerInstanceEntries.some(
     (entry) =>
       entry.instanceId === pendingHandoffSelection?.instanceId &&

apps/web/src/components/CommandPalette.tsx

@@ -146,7 +146,11 @@ import {
   waitForProject,
 } from "../state/entities";
 import { visibleLinkedThreads } from "@t3tools/client-runtime/state/threads";
-import { resolveThreadActionProjectRef, startNewThreadFromContext } from "../lib/chatThreadActions";
+import {
+  resolveThreadActionProjectRef,
+  startNewThreadFromContext,
+  threadHasStarted,
+} from "../lib/chatThreadActions";
 import {
   appendBrowsePathSegment,
   ensureBrowseDirectoryPath,
@@ -1397,6 +1401,7 @@ function OpenCommandPaletteDialog(props: {
               ? providersByEnvironment.get(promptLinkProjectRef.environmentId)
               : undefined) ?? [],
           threadModelSelection: activeThread?.modelSelection ?? null,
+          threadStarted: threadHasStarted(activeThread),
         };
   const plainPromptLink = promptLinkInput
     ? composerPromptLink({ ...promptLinkInput, withContext: false })

apps/web/src/components/chat/ChatComposer.tsx

@@ -86,6 +86,7 @@ import {
 } from "../../composer-logic";
 import { DEFAULT_COMPOSER_PLACEHOLDER } from "../../composerPlaceholder";
 import { deriveComposerSendState, getAntigravitySendBlockReason } from "../ChatView.logic";
+import { threadHasStarted } from "../../lib/chatThreadActions";
 import {
   dataTransferHasComposerMention,
   makeComposerMentionDragHandlers,
@@ -888,8 +889,8 @@ export const ChatComposer = memo(function ChatComposer(props: ChatComposerProps)
     threadModelSelection: activeThreadModelSelection,
     projectModelSelection: activeProjectDefaultModelSelection,
     promptInjectionState: getComposerPromptInjectionState(prompt),
+    threadStarted: threadHasStarted(activeThread),
     candidateInstanceIds: [
-      composerDraft.activeProvider ?? null,
       activeThread?.runtime?.providerInstanceId,
       activeThreadModelSelection?.instanceId,
       activeProjectDefaultModelSelection?.instanceId,

apps/web/src/components/chat/useComposerProviderModel.ts

@@ -3,6 +3,7 @@ import {
   deriveEffectiveComposerModelState,
   useComposerDraftModelState,
 } from "../../composerDraftStore";
+import { draftModelSelectionApplies } from "../../lib/chatThreadActions";
 import {
   type ModelSelection,
   type ProjectId,
@@ -35,6 +36,7 @@ export function useComposerProviderModel(
     readonly threadModelSelection: ModelSelection | null | undefined;
     readonly projectModelSelection: ModelSelection | null | undefined;
     readonly promptInjectionState: ReturnType<typeof getComposerPromptInjectionState>;
+    readonly threadStarted: boolean;
   },
 ) {
   const {
@@ -48,6 +50,7 @@ export function useComposerProviderModel(
     candidateInstanceIds,
     lockedProvider,
     lockedInstanceId,
+    threadStarted,
   } = input;
   const draftModelState = useComposerDraftModelState(threadRef);
   const providerInstanceEntries: ReadonlyArray<ProviderInstanceEntry> = providerInstanceEntriesFor(
@@ -57,7 +60,12 @@ export function useComposerProviderModel(
   );
   const selection = resolveComposerProviderSelection({
     entries: providerInstanceEntries,
-    candidateInstanceIds,
+    candidateInstanceIds: [
+      draftModelSelectionApplies(draftModelState, threadStarted)
+        ? draftModelState.activeProvider
+        : null,
+      ...candidateInstanceIds,
+    ],
     lockedProvider,
     lockedInstanceId,
   });
@@ -67,6 +75,7 @@ export function useComposerProviderModel(
     selection.selectedProviderEntry?.driverKind ?? selection.requestedDriverKind;
   const modelState = deriveEffectiveComposerModelState({
     draft: draftModelState,
+    threadStarted,
     providers: providerStatuses,
     selectedProvider,
     selectedInstanceId,

apps/web/src/components/chat/useComposerSelection.browser.test.tsx

@@ -139,6 +139,7 @@ it("switches back to the thread's stored model while the session runs on another
     expect(
       deriveEffectiveComposerModelState({
         draft,
+        threadStarted: true,
         providers,
         selectedProvider: ProviderDriverKind.make("cursor"),
         selectedInstanceId: cursor,
@@ -175,3 +176,33 @@ it("saves a re-picked model again when its first save failed", async () => {
   });
   await vi.waitFor(() => expect(setModelSelection.mock.calls).toEqual([[autoSave], [autoSave]]));
 });
+
+it("saves a pick of a seeded model the started thread does not show", async () => {
+  const { setModelSelection } = setup();
+  setModelSelection.mockResolvedValue(AsyncResult.success(undefined));
+  const thread = cursorThread("thread-cursor-seeded");
+  appAtomRegistry.set(shellAtom(thread.id), thread);
+  useComposerDraftStore
+    .getState()
+    .setModelSelection(
+      scopeThreadRef(environmentId, thread.id),
+      createModelSelection(cursor, "auto-smart"),
+    );
+  await using _screen = await render(
+    <AppAtomRegistryProvider>
+      <Picker thread={thread} runtime={null} model="auto-smart" />
+    </AppAtomRegistryProvider>,
+  );
+  await page.getByRole("button", { name: "Pick the model" }).click();
+
+  await vi.waitFor(() =>
+    expect(setModelSelection).toHaveBeenCalledWith(
+      expect.objectContaining({
+        input: {
+          threadId: thread.id,
+          modelSelection: expect.objectContaining({ instanceId: cursor, model: "auto-smart" }),
+        },
+      }),
+    ),
+  );
+});

apps/web/src/components/chat/useComposerSelection.ts

@@ -18,7 +18,11 @@ import { type SetStateAction } from "react";
 import { useNavigate } from "@tanstack/react-router";
 import { toastManager } from "../ui/toast";
 import { resolveAppModelSelectionForInstance } from "../../modelSelection";
-import { resolveNewDraftStartFromOrigin } from "../../lib/chatThreadActions";
+import {
+  draftModelSelectionApplies,
+  resolveNewDraftStartFromOrigin,
+  threadHasStarted,
+} from "../../lib/chatThreadActions";
 import { type DraftThreadEnvMode, useComposerDraftStore } from "../../composerDraftStore";
 import {
   getStartedThreadModelChangeBlockReason,
@@ -161,7 +165,10 @@ export function useComposerSelection(input: ComposerSelectionInput) {
       { preserveUnavailableSelection: true },
     );
     const threadRef = scopeThreadRef(activeThread.environmentId, activeThread.id);
-    const draft = useComposerDraftStore.getState().getComposerDraft(threadRef);
+    const storedDraft = useComposerDraftStore.getState().getComposerDraft(threadRef);
+    const draft = draftModelSelectionApplies(storedDraft, threadHasStarted(activeThread))
+      ? storedDraft
+      : null;
     const shownInstanceId =
       draft?.activeProvider ??
       activeRuntime?.providerInstanceId ??

apps/web/src/components/promptLinks/copyPromptLink.ts

@@ -15,6 +15,7 @@ import {
 import { type ComposerThreadTarget, useComposerDraftStore } from "~/composerDraftStore";
 import { writeTextToClipboard } from "~/hooks/useCopyToClipboard";
 import { configuredHostedAppUrl } from "~/hostedPairing";
+import { draftModelSelectionApplies } from "~/lib/chatThreadActions";
 
 import { stackedThreadToast, toastManager } from "../ui/toast";
 
@@ -48,14 +49,16 @@ export function composerPromptLink(input: {
   readonly project: EnvironmentProject | undefined;
   readonly providers: ReadonlyArray<ServerProvider>;
   readonly threadModelSelection: ModelSelection | null;
+  readonly threadStarted: boolean;
   readonly withContext: boolean;
 }): string | null {
   const draft = useComposerDraftStore.getState().getComposerDraft(input.target);
   if (!draft) return null;
   if (!input.withContext) return promptLinkFor(draft.prompt);
   const selection =
-    (draft.activeProvider ? draft.modelSelectionByProvider[draft.activeProvider] : undefined) ??
-    input.threadModelSelection;
+    (draft.activeProvider && draftModelSelectionApplies(draft, input.threadStarted)
+      ? draft.modelSelectionByProvider[draft.activeProvider]
+      : undefined) ?? input.threadModelSelection;
   const provider = selection
     ? (input.providers.find((candidate) => candidate.instanceId === selection.instanceId)?.driver ??
       null)