diff --git a/.changeset/empty-first-post-transition.md b/.changeset/empty-first-post-transition.md
new file mode 100644
index 0000000..1d4499e
--- /dev/null
+++ b/.changeset/empty-first-post-transition.md
@@ -0,0 +1,5 @@
+---
+"sideshow": patch
+---
+
+Keep first-run onboarding visible until the first post arrives and poll as a fallback while waiting.
diff --git a/e2e/viewer.spec.ts b/e2e/viewer.spec.ts
index 6a02943..365ac2e 100644
--- a/e2e/viewer.spec.ts
+++ b/e2e/viewer.spec.ts
@@ -66,6 +66,32 @@ test("snippet published over HTTP appears live via SSE, no reload", async ({ pag
   await expect(page.locator(".sess-title")).toContainText("e2e session");
 });
 
+test("empty onboarding polls into Home when the first post arrives", async ({ page, server }) => {
+  await page.route("**/api/events", (route) => route.abort());
+  await page.goto(server.url);
+  await expect(page.locator("#onboard")).toBeVisible();
+
+  await publish(server.url, { html: "<p>first</p>", title: "First post", agent: "e2e" });
+
+  await expect(page.getByRole("heading", { name: "Home" })).toBeVisible({ timeout: 6_000 });
+  await expect(page.locator(".home-card-title")).toHaveText("First post");
+  await expect(page.locator("#onboard")).toBeHidden();
+});
+
+test("an empty session alone keeps first-run onboarding visible", async ({ page, server }) => {
+  await fetch(`${server.url}/api/sessions`, {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({ agent: "idle", title: "Empty one" }),
+  });
+
+  await page.goto(server.url);
+
+  await expect(page.locator("#onboard")).toBeVisible();
+  await expect(page.getByRole("heading", { name: "Connect your first agent" })).toBeVisible();
+  await expect(page.locator(".sess.sel")).toHaveCount(0);
+});
+
 test("a surface kind this viewer doesn't know shows a refresh hint, not a broken diff", async ({
   page,
   server,
diff --git a/viewer/src/App.tsx b/viewer/src/App.tsx
index b89d8fb..a23d5f3 100644
--- a/viewer/src/App.tsx
+++ b/viewer/src/App.tsx
@@ -70,8 +70,10 @@ function isConnectPath() {
   return rest === "/connect";
 }
 const [connectPath, setConnectPath] = createSignal(isConnectPath());
+const hasPosts = () => sessions.some((s) => s.surfaceCount > 0);
+const emptyWorkspace = () => initialLoaded() && !selected() && !hasPosts();
 const homePath = () =>
-  !streamMode() && !connectPath() && initialLoaded() && sessions.length > 0 && !selected();
+  !streamMode() && !connectPath() && initialLoaded() && hasPosts() && !selected();
 
 // Stream-only layout: no sidebar, session list, or session chrome — just the
 // current session's stream. Driven by the host's `layout` (cloud embed) or the
@@ -706,8 +708,16 @@ function SessionTitle(props: { current: SessionRow | undefined }) {
 }
 
 function Onboard() {
+  createEffect(() => {
+    if (!emptyWorkspace() || isReadonly() || connectPath()) return;
+    const poll = setInterval(() => {
+      if (!document.hidden) void refreshSessionsQuiet();
+    }, 1500);
+    onCleanup(() => clearInterval(poll));
+  });
+
   return (
-    <div id="onboard" hidden={!initialLoaded() || sessions.length > 0}>
+    <div id="onboard" hidden={!emptyWorkspace()}>
       {/* Host-overridable region (SLOTS.empty): an embedder projects its own
           first-run onboarding here. The fallback below is the self-hosted
           default — setup snippets that assume a local sideshow on port 8228,
@@ -719,7 +729,7 @@ function Onboard() {
           fallback={
             <>
               <h1>Nothing here yet</h1>
-              <p class="sub">This sideshow workspace does not have any sessions yet.</p>
+              <p class="sub">This sideshow workspace does not have any posts yet.</p>
             </>
           }
         >
diff --git a/viewer/src/state.ts b/viewer/src/state.ts
index 40dc315..42bd952 100644
--- a/viewer/src/state.ts
+++ b/viewer/src/state.ts
@@ -233,19 +233,20 @@ export async function refreshSessions(targetPostId?: string | null) {
   }
 
   if (!selected() && sessions.length > 0) {
-    // Check the route first, then localStorage, then fall back to first session.
-    // A host that owns a session-less landing (homeView) skips that fallback: it
-    // honors a deep-linked route session but otherwise stays session-less so the
-    // host's home shows with nothing selected (no auto-open, no highlight).
+    // Check the route first, then localStorage, then fall back to the first
+    // session with posts. Empty sessions alone keep the first-run onboarding up:
+    // the useful transition is from "connect an agent" to real output.
     const route = host().router.get();
+    const sessionsWithPosts = sessions.filter((s) => s.surfaceCount > 0);
     const lastId = localStorage.getItem(LAST_SESSION_KEY);
-    const validLastId = lastId && sessions.some((s) => s.id === lastId) ? lastId : null;
+    const validLastId = lastId && sessionsWithPosts.some((s) => s.id === lastId) ? lastId : null;
     const fallback =
       host().homeView ||
       isConnectRoute() ||
-      (isSessionlessHomeRoute(route) && !validLastId && sessions.length > 1)
+      sessionsWithPosts.length === 0 ||
+      (isSessionlessHomeRoute(route) && !validLastId && sessionsWithPosts.length > 1)
         ? null
-        : validLastId || sessions[0].id;
+        : validLastId || sessionsWithPosts[0].id;
     const target =
       (route.sessionId && sessions.some((s) => s.id === route.sessionId) && route.sessionId) ||
       fallback;