diff --git a/apps/web/src/components/chat/DraftHeroHeadline.tsx b/apps/web/src/components/chat/DraftHeroHeadline.tsx
index 3f50d3818b5..448e8bc2334 100644
--- a/apps/web/src/components/chat/DraftHeroHeadline.tsx
+++ b/apps/web/src/components/chat/DraftHeroHeadline.tsx
@@ -1,21 +1,28 @@
 import type { ScopedProjectRef } from "@t3tools/contracts";
 import { scopedProjectKey, scopeProjectRef } from "@t3tools/client-runtime/environment";
-import { FolderPlusIcon } from "lucide-react";
-import { useCallback, useMemo } from "react";
+import { FolderPlusIcon, SearchIcon } from "lucide-react";
+import { useCallback, useMemo, useRef, useState } from "react";
 
 import { openCommandPalette } from "~/commandPaletteBus";
 import { useNewThreadHandler } from "~/hooks/useHandleNewThread";
 import { useProjects, useThreadShells } from "~/state/entities";
 import { sortScopedProjectsForSidebar } from "../Sidebar.logic";
 import {
-  Menu,
-  MenuItem,
-  MenuPopup,
-  MenuRadioGroup,
-  MenuRadioItem,
-  MenuSeparator,
-  MenuTrigger,
-} from "../ui/menu";
+  Combobox,
+  ComboboxInput,
+  ComboboxItem,
+  ComboboxListVirtualized,
+  ComboboxPopup,
+  ComboboxSeparator,
+  ComboboxTrigger,
+} from "../ui/combobox";
+import {
+  DRAFT_HERO_NEW_PROJECT_ITEM,
+  filterDraftHeroProjects,
+  getDraftHeroFilteredPickerItems,
+  getDraftHeroProjectPickerItemValue,
+  resolveDraftHeroPickerKeyAction,
+} from "./draftHeroProjectSearch";
 
 interface DraftHeroHeadlineProps {
   readonly activeProjectRef: ScopedProjectRef | null;
@@ -30,66 +37,173 @@ export function DraftHeroHeadline({
   const threads = useThreadShells();
   const handleNewThread = useNewThreadHandler();
   const openAddProject = useCallback(() => openCommandPalette({ open: "add-project" }), []);
+  const [isProjectPickerOpen, setIsProjectPickerOpen] = useState(false);
+  const [projectQuery, setProjectQuery] = useState("");
+  const hasNewProjectKeyboardIntentRef = useRef(false);
 
   const orderedProjects = useMemo(
     () => sortScopedProjectsForSidebar(projects, threads, "updated_at"),
     [projects, threads],
   );
+  const filteredProjects = useMemo(
+    () => filterDraftHeroProjects(orderedProjects, projectQuery),
+    [orderedProjects, projectQuery],
+  );
+  const filteredProjectItems = useMemo(
+    () =>
+      getDraftHeroFilteredPickerItems(
+        filteredProjects.map((project) =>
+          getDraftHeroProjectPickerItemValue(
+            scopedProjectKey(scopeProjectRef(project.environmentId, project.id)),
+          ),
+        ),
+      ),
+    [filteredProjects],
+  );
   const projectByKey = useMemo(
     () =>
       new Map(
         orderedProjects.map(
           (project) =>
             [
-              scopedProjectKey(scopeProjectRef(project.environmentId, project.id)),
+              getDraftHeroProjectPickerItemValue(
+                scopedProjectKey(scopeProjectRef(project.environmentId, project.id)),
+              ),
               project,
             ] as const,
         ),
       ),
     [orderedProjects],
   );
-  const activeProjectKey = activeProjectRef === null ? "" : scopedProjectKey(activeProjectRef);
+  const activeProjectKey =
+    activeProjectRef === null
+      ? ""
+      : getDraftHeroProjectPickerItemValue(scopedProjectKey(activeProjectRef));
   const hasResolvedProject = activeProjectTitle !== null;
   const canChooseProject = orderedProjects.length > 0;
   const shouldShowProjectMenu = canChooseProject;
+  const hasFailedProjectSearch = projectQuery.trim().length > 0 && filteredProjects.length === 0;
 
   const projectSelector = shouldShowProjectMenu ? (
-    <Menu>
-      <MenuTrigger
+    <Combobox
+      autoHighlight
+      filter={null}
+      items={[
+        ...orderedProjects.map((project) =>
+          getDraftHeroProjectPickerItemValue(
+            scopedProjectKey(scopeProjectRef(project.environmentId, project.id)),
+          ),
+        ),
+        DRAFT_HERO_NEW_PROJECT_ITEM,
+      ]}
+      filteredItems={filteredProjectItems}
+      open={isProjectPickerOpen}
+      value={activeProjectKey}
+      onOpenChange={(open) => {
+        setIsProjectPickerOpen(open);
+        if (!open) {
+          hasNewProjectKeyboardIntentRef.current = false;
+          setProjectQuery("");
+        }
+      }}
+      onValueChange={(value) => {
+        if (value === DRAFT_HERO_NEW_PROJECT_ITEM) {
+          setIsProjectPickerOpen(false);
+          openAddProject();
+          return;
+        }
+        if (!value || value === activeProjectKey) {
+          setIsProjectPickerOpen(false);
+          return;
+        }
+        const project = projectByKey.get(value);
+        if (!project) {
+          return;
+        }
+        setIsProjectPickerOpen(false);
+        void handleNewThread(scopeProjectRef(project.environmentId, project.id), {
+          replace: true,
+        });
+      }}
+    >
+      <ComboboxTrigger
         aria-label={hasResolvedProject ? "Change project" : "Choose a project"}
         className="pointer-events-auto inline cursor-pointer border-current border-b border-dotted text-foreground underline-offset-8 transition-opacity hover:opacity-75 focus-visible:rounded-sm focus-visible:outline-hidden focus-visible:ring-2 focus-visible:ring-ring"
       >
         {activeProjectTitle ?? "Choose a project"}
-      </MenuTrigger>
-      <MenuPopup align="center" className="max-h-80 w-64 overflow-y-auto">
-        <MenuRadioGroup
-          value={activeProjectKey}
-          onValueChange={(value) => {
-            const project = projectByKey.get(value as string);
-            if (!project || value === activeProjectKey) {
-              return;
-            }
-            void handleNewThread(scopeProjectRef(project.environmentId, project.id), {
-              replace: true,
-            });
-          }}
-        >
-          {orderedProjects.map((project) => {
-            const key = scopedProjectKey(scopeProjectRef(project.environmentId, project.id));
-            return (
-              <MenuRadioItem key={key} value={key} closeOnClick>
-                <span className="min-w-0 truncate">{project.title}</span>
-              </MenuRadioItem>
-            );
-          })}
-        </MenuRadioGroup>
-        <MenuSeparator />
-        <MenuItem onClick={openAddProject}>
-          <FolderPlusIcon />
-          New project
-        </MenuItem>
-      </MenuPopup>
-    </Menu>
+      </ComboboxTrigger>
+      <ComboboxPopup align="center" className="w-72 max-w-[calc(100vw-1rem)]">
+        <div className="shrink-0 px-3 pt-2.5">
+          <div className="relative -translate-y-px border-b border-border/70 pb-1.5 transition-colors focus-within:border-ring">
+            <SearchIcon
+              aria-hidden="true"
+              className="pointer-events-none absolute top-1.5 left-0 size-4 text-muted-foreground/55"
+            />
+            <ComboboxInput
+              autoFocus
+              className="[&_input]:h-6.5 [&_input]:ps-5 [&_input]:font-sans [&_input]:leading-6.5"
+              inputClassName="rounded-none bg-transparent text-sm"
+              placeholder="Search projects..."
+              showTrigger={false}
+              size="sm"
+              unstyled
+              value={projectQuery}
+              onChange={(event) => {
+                hasNewProjectKeyboardIntentRef.current = false;
+                setProjectQuery(event.target.value);
+              }}
+              onKeyDownCapture={(event) => {
+                // A failed search leaves the footer as Base UI's only highlighted item.
+                // Require an arrow-key gesture before letting Enter commit that action.
+                const action = resolveDraftHeroPickerKeyAction({
+                  key: event.key,
+                  isComposing: event.nativeEvent.isComposing,
+                  keyCode: event.nativeEvent.keyCode,
+                  hasFailedProjectSearch,
+                  hasNewProjectKeyboardIntent: hasNewProjectKeyboardIntentRef.current,
+                });
+                if (action === "preserve-composition") {
+                  // Let the browser commit the IME text, but do not let Base UI
+                  // interpret the same Enter as selecting the highlighted footer.
+                  event.stopPropagation();
+                } else if (action === "enable-new-project") {
+                  hasNewProjectKeyboardIntentRef.current = true;
+                } else if (action === "block-selection") {
+                  event.preventDefault();
+                  event.stopPropagation();
+                }
+              }}
+            />
+          </div>
+        </div>
+        {filteredProjects.length === 0 ? (
+          <div className="p-2 text-center text-base text-muted-foreground sm:text-sm" role="status">
+            No matching projects.
+          </div>
+        ) : null}
+        <ComboboxListVirtualized className="flex max-h-64 min-h-0 flex-col overflow-hidden p-0">
+          <div className="min-h-0 flex-auto overflow-y-auto overscroll-contain p-1">
+            {filteredProjects.map((project) => {
+              const key = getDraftHeroProjectPickerItemValue(
+                scopedProjectKey(scopeProjectRef(project.environmentId, project.id)),
+              );
+              return (
+                <ComboboxItem key={key} value={key}>
+                  <span className="min-w-0 truncate">{project.title}</span>
+                </ComboboxItem>
+              );
+            })}
+          </div>
+          <div className="shrink-0 px-1 pb-1">
+            <ComboboxSeparator />
+            <ComboboxItem hideIndicator value={DRAFT_HERO_NEW_PROJECT_ITEM}>
+              <FolderPlusIcon />
+              New project
+            </ComboboxItem>
+          </div>
+        </ComboboxListVirtualized>
+      </ComboboxPopup>
+    </Combobox>
   ) : (
     <button
       type="button"
diff --git a/apps/web/src/components/chat/draftHeroProjectSearch.test.ts b/apps/web/src/components/chat/draftHeroProjectSearch.test.ts
new file mode 100644
index 00000000000..0eefdd1da57
--- /dev/null
+++ b/apps/web/src/components/chat/draftHeroProjectSearch.test.ts
@@ -0,0 +1,119 @@
+import { describe, expect, it } from "vite-plus/test";
+
+import {
+  DRAFT_HERO_NEW_PROJECT_ITEM,
+  filterDraftHeroProjects,
+  getDraftHeroFilteredPickerItems,
+  getDraftHeroProjectPickerItemValue,
+  resolveDraftHeroPickerKeyAction,
+} from "./draftHeroProjectSearch";
+
+const projects = [
+  { title: "T3 Code", workspaceRoot: "/work/t3code" },
+  { title: "Mobile App", workspaceRoot: "/work/products/mobile" },
+  { title: "Marketing Site", workspaceRoot: "/work/products/marketing" },
+];
+
+describe("filterDraftHeroProjects", () => {
+  it("narrows candidates as the title query becomes more specific", () => {
+    expect(filterDraftHeroProjects(projects, "m").map((project) => project.title)).toEqual([
+      "Mobile App",
+      "Marketing Site",
+    ]);
+    expect(filterDraftHeroProjects(projects, "mob").map((project) => project.title)).toEqual([
+      "Mobile App",
+    ]);
+  });
+
+  it("matches project paths and multiple query tokens", () => {
+    expect(
+      filterDraftHeroProjects(projects, "products market").map((project) => project.title),
+    ).toEqual(["Marketing Site"]);
+  });
+
+  it("preserves candidate order for an empty query", () => {
+    expect(filterDraftHeroProjects(projects, "   ")).toEqual(projects);
+  });
+});
+
+describe("getDraftHeroFilteredPickerItems", () => {
+  it("keeps project values disjoint even when their scoped key matches the action value", () => {
+    const projectItem = getDraftHeroProjectPickerItemValue(DRAFT_HERO_NEW_PROJECT_ITEM);
+
+    expect(projectItem).not.toBe(DRAFT_HERO_NEW_PROJECT_ITEM);
+    expect(getDraftHeroFilteredPickerItems([projectItem])).toEqual([
+      projectItem,
+      DRAFT_HERO_NEW_PROJECT_ITEM,
+    ]);
+  });
+
+  it("keeps New project in the navigable collection after a failed search", () => {
+    expect(getDraftHeroFilteredPickerItems([])).toEqual([DRAFT_HERO_NEW_PROJECT_ITEM]);
+  });
+
+  it("keeps New project reachable when browsing or navigating successful search results", () => {
+    expect(getDraftHeroFilteredPickerItems(["project-1"])).toEqual([
+      "project-1",
+      DRAFT_HERO_NEW_PROJECT_ITEM,
+    ]);
+  });
+});
+
+describe("resolveDraftHeroPickerKeyAction", () => {
+  it("blocks an immediate Enter after a failed project search", () => {
+    expect(
+      resolveDraftHeroPickerKeyAction({
+        key: "Enter",
+        isComposing: false,
+        keyCode: 13,
+        hasFailedProjectSearch: true,
+        hasNewProjectKeyboardIntent: false,
+      }),
+    ).toBe("block-selection");
+  });
+
+  it("allows deliberate ArrowDown then Enter access to New project", () => {
+    const navigationAction = resolveDraftHeroPickerKeyAction({
+      key: "ArrowDown",
+      isComposing: false,
+      keyCode: 40,
+      hasFailedProjectSearch: true,
+      hasNewProjectKeyboardIntent: false,
+    });
+    expect(navigationAction).toBe("enable-new-project");
+
+    expect(
+      resolveDraftHeroPickerKeyAction({
+        key: "Enter",
+        isComposing: false,
+        keyCode: 13,
+        hasFailedProjectSearch: true,
+        hasNewProjectKeyboardIntent: navigationAction === "enable-new-project",
+      }),
+    ).toBe("allow");
+  });
+
+  it("allows Enter to commit an active IME composition", () => {
+    expect(
+      resolveDraftHeroPickerKeyAction({
+        key: "Enter",
+        isComposing: true,
+        keyCode: 13,
+        hasFailedProjectSearch: true,
+        hasNewProjectKeyboardIntent: false,
+      }),
+    ).toBe("preserve-composition");
+  });
+
+  it("allows the legacy 229 composition fallback", () => {
+    expect(
+      resolveDraftHeroPickerKeyAction({
+        key: "Enter",
+        isComposing: false,
+        keyCode: 229,
+        hasFailedProjectSearch: true,
+        hasNewProjectKeyboardIntent: false,
+      }),
+    ).toBe("preserve-composition");
+  });
+});
diff --git a/apps/web/src/components/chat/draftHeroProjectSearch.ts b/apps/web/src/components/chat/draftHeroProjectSearch.ts
new file mode 100644
index 00000000000..b197aaf8c51
--- /dev/null
+++ b/apps/web/src/components/chat/draftHeroProjectSearch.ts
@@ -0,0 +1,60 @@
+type SearchableProject = {
+  readonly title: string;
+  readonly workspaceRoot: string;
+};
+
+const DRAFT_HERO_PROJECT_ITEM_PREFIX = "draft-hero:project:";
+
+export const DRAFT_HERO_NEW_PROJECT_ITEM = "draft-hero:action:new-project";
+
+export function getDraftHeroProjectPickerItemValue(projectKey: string): string {
+  return `${DRAFT_HERO_PROJECT_ITEM_PREFIX}${projectKey}`;
+}
+
+export type DraftHeroPickerKeyAction =
+  | "allow"
+  | "block-selection"
+  | "enable-new-project"
+  | "preserve-composition";
+
+export function filterDraftHeroProjects<T extends SearchableProject>(
+  projects: ReadonlyArray<T>,
+  query: string,
+): T[] {
+  const tokens = query.trim().toLocaleLowerCase().split(/\s+/).filter(Boolean);
+
+  if (tokens.length === 0) {
+    return [...projects];
+  }
+
+  return projects.filter((project) => {
+    const searchText = `${project.title}\n${project.workspaceRoot}`.toLocaleLowerCase();
+    return tokens.every((token) => searchText.includes(token));
+  });
+}
+
+export function getDraftHeroFilteredPickerItems(projectItems: ReadonlyArray<string>): string[] {
+  return [...projectItems, DRAFT_HERO_NEW_PROJECT_ITEM];
+}
+
+export function resolveDraftHeroPickerKeyAction(input: {
+  readonly key: string;
+  readonly isComposing: boolean;
+  readonly keyCode: number;
+  readonly hasFailedProjectSearch: boolean;
+  readonly hasNewProjectKeyboardIntent: boolean;
+}): DraftHeroPickerKeyAction {
+  if (input.isComposing || input.keyCode === 229) {
+    return "preserve-composition";
+  }
+  if (!input.hasFailedProjectSearch) {
+    return "allow";
+  }
+  if (input.key === "ArrowDown" || input.key === "ArrowUp") {
+    return "enable-new-project";
+  }
+  if (input.key === "Enter" && !input.hasNewProjectKeyboardIntent) {
+    return "block-selection";
+  }
+  return "allow";
+}