feat(ui): show serving binary version

Expose the compiled server version through the existing UI config endpoint and render it beside the product name. Keep older or unavailable config responses compatible by hiding the label, with focused frontend and native endpoint coverage.

Fixes DeusData#1820

Signed-off-by: Rares Popa <2606875+rarepops@users.noreply.github.com>

Author: rarepops

graph-ui/src/App.test.tsx

@@ -0,0 +1,59 @@
+/* @vitest-environment jsdom */
+import "@testing-library/jest-dom/vitest";
+import { cleanup, render, screen, waitFor } from "@testing-library/react";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { App } from "./App";
+import { messages } from "./lib/i18n";
+
+vi.mock("./components/GraphTab", () => ({ GraphTab: () => null }));
+vi.mock("./components/StatsTab", () => ({ StatsTab: () => null }));
+vi.mock("./components/ControlTab", () => ({ ControlTab: () => null }));
+vi.mock("./lib/i18n", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("./lib/i18n")>();
+  return { ...actual, useUiMessages: () => messages.en };
+});
+
+describe("App", () => {
+  afterEach(() => {
+    cleanup();
+    vi.unstubAllGlobals();
+    window.history.replaceState(null, "", "/");
+  });
+
+  it("shows the serving binary version", async () => {
+    vi.stubGlobal("fetch", vi.fn(async () =>
+      new Response(JSON.stringify({ lang: "en", version: "0.10.8" }), {
+        status: 200,
+        headers: { "Content-Type": "application/json" },
+      }),
+    ));
+
+    render(<App />);
+
+    expect(await screen.findByText("v0.10.8")).toBeVisible();
+  });
+
+  it("hides the version when the config has no string version", async () => {
+    const fetchMock = vi.fn(async () =>
+      new Response(JSON.stringify({ lang: "en", version: 108 }), { status: 200 }),
+    );
+    vi.stubGlobal("fetch", fetchMock);
+
+    render(<App />);
+
+    await waitFor(() => expect(fetchMock).toHaveBeenCalledWith("/api/ui-config"));
+    expect(screen.queryByTitle("Server version")).not.toBeInTheDocument();
+  });
+
+  it("hides the version when the config request fails", async () => {
+    const fetchMock = vi.fn(async () => {
+      throw new Error("offline");
+    });
+    vi.stubGlobal("fetch", fetchMock);
+
+    render(<App />);
+
+    await waitFor(() => expect(fetchMock).toHaveBeenCalledWith("/api/ui-config"));
+    expect(screen.queryByTitle("Server version")).not.toBeInTheDocument();
+  });
+});

graph-ui/src/App.tsx

@@ -33,8 +33,24 @@ function routeUrl(tab: TabId, project: string | null): string {
 export function App() {
   const t = useUiMessages();
   const [route, setRoute] = useState<RouteState>(readRoute);
+  const [version, setVersion] = useState<string | null>(null);
   const { tab: activeTab, project: selectedProject } = route;
 
+  useEffect(() => {
+    let cancelled = false;
+    void fetch("/api/ui-config")
+      .then((response) => (response.ok ? response.json() : null))
+      .then((config) => {
+        if (!cancelled && typeof config?.version === "string" && config.version) {
+          setVersion(config.version);
+        }
+      })
+      .catch(() => {});
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
   /* Normalize the URL on first load so it always carries the current route. */
   useEffect(() => {
     const initial = readRoute();
@@ -73,6 +89,14 @@ export function App() {
             <span className="text-[13px] font-semibold text-foreground/90 tracking-tight">
               Codebase Memory
             </span>
+            {version && (
+              <span
+                className="translate-y-px text-[10px] font-mono text-foreground/30"
+                title="Server version"
+              >
+                {version.startsWith("v") ? version : `v${version}`}
+              </span>
+            )}
           </div>
 
           {/* Tabs inline in header */}

src/ui/http_server.c

@@ -66,6 +66,10 @@
 
 /* ── Constants ────────────────────────────────────────────────── */
 
+#ifndef CBM_VERSION
+#define CBM_VERSION "dev"
+#endif
+
 /* Max JSON-RPC request body size (1 MB) — transport enforces the same cap. */
 #define MAX_BODY_SIZE CBM_HTTP_MAX_BODY
 
@@ -143,8 +147,10 @@ static void handle_ui_config(cbm_http_conn_t *c, const cbm_http_req_t *req) {
      * audit forbids hardcoded external URLs in graph-ui source (external
      * targets must come from an auditable backend response, same pattern as
      * the /api/repo-info deep-links). */
-    cbm_http_replyf(c, 200, g_cors_json, "{\"lang\":\"%s\",\"upstream_issues_url\":\"%s\"}",
-                    lang_buf, "https://github.com/DeusData/codebase-memory-mcp/issues/new");
+    cbm_http_replyf(c, 200, g_cors_json,
+                    "{\"lang\":\"%s\",\"version\":\"%s\",\"upstream_issues_url\":\"%s\"}",
+                    lang_buf, CBM_VERSION,
+                    "https://github.com/DeusData/codebase-memory-mcp/issues/new");
 }
 
 /* ── Server state ─────────────────────────────────────────────── */

tests/test_httpd.c

@@ -33,6 +33,9 @@
 #include <stdatomic.h>
 #include <stdlib.h>
 #include <string.h>
+#ifndef CBM_VERSION
+#define CBM_VERSION "dev"
+#endif
 #ifndef _WIN32
 #include <sys/stat.h>
 #endif
@@ -1573,6 +1576,23 @@ TEST(ui_server_ui_config_detects_zh_accept_language) {
     PASS();
 }
 
+TEST(ui_server_ui_config_includes_serving_version_issue1820) {
+    th_server_t ts;
+    ASSERT_EQ(th_server_start(&ts), 0);
+
+    char resp[4096];
+    int n = th_http(cbm_http_server_port(ts.srv), "GET /api/ui-config HTTP/1.1\r\n\r\n", resp,
+                    sizeof(resp));
+    ASSERT_TRUE(n > 0);
+    ASSERT_EQ(th_status(resp), 200);
+    char expected_version[128];
+    snprintf(expected_version, sizeof(expected_version), "\"version\":\"%s\"", CBM_VERSION);
+    ASSERT_NOT_NULL(strstr(resp, expected_version));
+
+    th_server_stop(&ts);
+    PASS();
+}
+
 TEST(ui_server_ui_config_prefers_config_lang) {
     char tmpdir[256];
     snprintf(tmpdir, sizeof(tmpdir), "/tmp/cbm_httpd_cfg_XXXXXX");
@@ -2397,6 +2417,7 @@ SUITE(httpd) {
     RUN_TEST(ui_server_delete_project_invalid_name_keeps_watch);
     RUN_TEST(ui_server_delete_project_unlink_failure_keeps_watch);
     RUN_TEST(ui_server_ui_config_detects_zh_accept_language);
+    RUN_TEST(ui_server_ui_config_includes_serving_version_issue1820);
     RUN_TEST(ui_server_ui_config_prefers_config_lang);
     RUN_TEST(ui_server_slow_request_hits_deadline);
     RUN_TEST(ui_server_access_log_redacts_query);