Clarify Codex skill invocation hint in the composer

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

@@ -3,6 +3,8 @@ import { afterEach, describe, expect, it, vi } from "vitest";
 import { useStore } from "../store";
 
 import {
+  buildDefaultComposerPlaceholder,
+  buildDisconnectedComposerPlaceholder,
   buildExpiredTerminalContextToastCopy,
   createLocalDispatchSnapshot,
   deriveComposerSendState,
@@ -75,6 +77,34 @@ describe("buildExpiredTerminalContextToastCopy", () => {
   });
 });
 
+describe("buildDefaultComposerPlaceholder", () => {
+  it("mentions skills for Codex threads", () => {
+    expect(buildDefaultComposerPlaceholder("codex")).toBe(
+      "Ask anything, @tag files/folders, type $ to mention skills, or use / to show available commands",
+    );
+  });
+
+  it("keeps non-Codex placeholders focused on supported composer commands", () => {
+    expect(buildDefaultComposerPlaceholder("claudeAgent")).toBe(
+      "Ask anything, @tag files/folders, or use / to show available commands",
+    );
+  });
+});
+
+describe("buildDisconnectedComposerPlaceholder", () => {
+  it("mentions skills for disconnected Codex threads", () => {
+    expect(buildDisconnectedComposerPlaceholder("codex")).toBe(
+      "Ask for follow-up changes, type $ to mention skills, or attach images",
+    );
+  });
+
+  it("keeps disconnected non-Codex placeholders unchanged", () => {
+    expect(buildDisconnectedComposerPlaceholder("claudeAgent")).toBe(
+      "Ask for follow-up changes or attach images",
+    );
+  });
+});
+
 const makeThread = (input?: {
   id?: ThreadId;
   latestTurn?: {

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

@@ -1,4 +1,10 @@
-import { ProjectId, type ModelSelection, type ThreadId, type TurnId } from "@t3tools/contracts";
+import {
+  ProjectId,
+  type ModelSelection,
+  type ProviderKind,
+  type ThreadId,
+  type TurnId,
+} from "@t3tools/contracts";
 import { type ChatMessage, type SessionPhase, type Thread, type ThreadSession } from "../types";
 import { randomUUID } from "~/lib/utils";
 import { type ComposerImageAttachment, type DraftThreadState } from "../composerDraftStore";
@@ -160,6 +166,20 @@ export function buildExpiredTerminalContextToastCopy(
   };
 }
 
+export function buildDefaultComposerPlaceholder(provider: ProviderKind): string {
+  if (provider === "codex") {
+    return "Ask anything, @tag files/folders, type $ to mention skills, or use / to show available commands";
+  }
+  return "Ask anything, @tag files/folders, or use / to show available commands";
+}
+
+export function buildDisconnectedComposerPlaceholder(provider: ProviderKind): string {
+  if (provider === "codex") {
+    return "Ask for follow-up changes, type $ to mention skills, or attach images";
+  }
+  return "Ask for follow-up changes or attach images";
+}
+
 export function threadHasStarted(thread: Thread | null | undefined): boolean {
   return Boolean(
     thread && (thread.latestTurn !== null || thread.messages.length > 0 || thread.session !== null),

apps/web/src/components/ChatView.tsx

@@ -171,6 +171,8 @@ import {
 import { ProviderStatusBanner } from "./chat/ProviderStatusBanner";
 import { ThreadErrorBanner } from "./chat/ThreadErrorBanner";
 import {
+  buildDefaultComposerPlaceholder,
+  buildDisconnectedComposerPlaceholder,
   buildExpiredTerminalContextToastCopy,
   buildLocalDraftThread,
   buildTemporaryWorktreeBranchName,
@@ -3951,8 +3953,8 @@ export default function ChatView({ threadId }: ChatViewProps) {
                             : showPlanFollowUpPrompt && activeProposedPlan
                               ? "Add feedback to refine the plan, or leave this blank to implement it"
                               : phase === "disconnected"
-                                ? "Ask for follow-up changes or attach images"
-                                : "Ask anything, @tag files/folders, or use / to show available commands"
+                                ? buildDisconnectedComposerPlaceholder(selectedProvider)
+                                : buildDefaultComposerPlaceholder(selectedProvider)
                       }
                       disabled={isConnecting || isComposerApprovalState}
                     />