diff --git a/Cargo.lock b/Cargo.lock
index f959656d6..4a628953f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -999,6 +999,31 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "craft-update"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=db19c373c8d59a545972ca340987aecfb3611a4b#db19c373c8d59a545972ca340987aecfb3611a4b"
+dependencies = [
+ "chrono",
+ "dunce",
+ "egui",
+ "flate2",
+ "getrandom 0.3.4",
+ "log",
+ "plist",
+ "semver",
+ "serde",
+ "serde_json",
+ "sha2",
+ "tar",
+ "tempfile",
+ "ureq",
+ "verifysign",
+ "winreg",
+ "winsafe",
+ "zip",
+]
+
 [[package]]
 name = "craft-window"
 version = "0.1.0"
@@ -1125,6 +1150,12 @@ dependencies = [
  "syn 2.0.119",
 ]
 
+[[package]]
+name = "deranged"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e9de72ce2ad1f90dc62fa25f0f430ef85eb4b0d8fa0be4f30373bc40a21d28e"
+
 [[package]]
 name = "dify"
 version = "0.8.0"
@@ -3004,6 +3035,18 @@ dependencies = [
  "jni-sys 0.3.1",
 ]
 
+[[package]]
+name = "nix"
+version = "0.31.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf20d2fde8ff38632c426f1165ed7436270b44f199fc55284c38276f9db47c3d"
+dependencies = [
+ "bitflags 2.13.2",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+]
+
 [[package]]
 name = "nohash-hasher"
 version = "0.2.0"
@@ -3019,6 +3062,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "num-conv"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "521739c6d2bac4aa25192232afe6841231376b2b26d4d9fae5ecf8ca5772e441"
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -3671,6 +3720,19 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
 
+[[package]]
+name = "plist"
+version = "1.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "327a4cb2ad49dc48adfdc9da89e22c64d488b508c67a044d71ba729e4521a285"
+dependencies = [
+ "base64 0.23.1",
+ "indexmap",
+ "quick-xml 0.42.0",
+ "serde",
+ "time",
+]
+
 [[package]]
 name = "png"
 version = "0.17.16"
@@ -3758,6 +3820,12 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "powerfmt"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a6394b9e965e73d0a289ee54f589087e2c676aedf60885baf52c76b771e4958"
+
 [[package]]
 name = "presser"
 version = "0.3.1"
@@ -3868,6 +3936,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "quick-xml"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41b1177fdf999d2321d3fb46ff47159d9c1fb9ad66a4879f8c50a0b504615e9b"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "quinn"
 version = "0.11.12"
@@ -4289,7 +4366,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48e13bd8c0e9365c43cfa5c9e8f9ad49d3c8444926c9aac819e0e4dc503c8fdf"
 dependencies = [
  "aws-lc-rs",
+ "log",
  "once_cell",
+ "ring",
  "rustls-pki-types",
  "rustls-webpki",
  "subtle",
@@ -4489,6 +4568,10 @@ name = "semver"
 version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
+dependencies = [
+ "serde",
+ "serde_core",
+]
 
 [[package]]
 name = "send_wrapper"
@@ -5257,6 +5340,36 @@ dependencies = [
  "zune-jpeg",
 ]
 
+[[package]]
+name = "time"
+version = "0.3.55"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cdb87b95ec50ddfa440816d227a17b2ccbdda963a316a727fda0fc4334f7d134"
+dependencies = [
+ "deranged",
+ "num-conv",
+ "powerfmt",
+ "serde_core",
+ "time-core",
+ "time-macros",
+]
+
+[[package]]
+name = "time-core"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e1c906769ad99c88eaa54e728060edef082f8e358ff32030cb7c7d315e81109"
+
+[[package]]
+name = "time-macros"
+version = "0.2.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e689342a48d2ea927c87ea50cabf8594854bf940e9310208848d680d668ed85"
+dependencies = [
+ "num-conv",
+ "time-core",
+]
+
 [[package]]
 name = "tiny-skia"
 version = "0.11.4"
@@ -5539,6 +5652,12 @@ dependencies = [
  "rustc-hash 2.1.3",
 ]
 
+[[package]]
+name = "typed-path"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ce898823d8cd0f028662d2f349694b1af0a5cc9be83f1d213a00d3147445e1e"
+
 [[package]]
 name = "typenum"
 version = "1.20.1"
@@ -5643,6 +5762,35 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
 
+[[package]]
+name = "ureq"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cde93ff05758a36a851a398a772b0b79a82fbe3c186a46f2696baaeaf84c966b"
+dependencies = [
+ "base64 0.23.1",
+ "flate2",
+ "log",
+ "percent-encoding",
+ "rustls",
+ "rustls-pki-types",
+ "rustls-platform-verifier",
+ "ureq-proto",
+ "utf8-zero",
+]
+
+[[package]]
+name = "ureq-proto"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841583fc36089d7d59419568ae157f43a5a03a2e5a81ba87c77d1596ef46e922"
+dependencies = [
+ "base64 0.23.1",
+ "http",
+ "httparse",
+ "log",
+]
+
 [[package]]
 name = "url"
 version = "2.5.8"
@@ -5705,6 +5853,12 @@ dependencies = [
  "xmlwriter",
 ]
 
+[[package]]
+name = "utf8-zero"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8c0a043c9540bae7c578c88f91dda8bd82e59ae27c21baca69c8b191aaf5a6e"
+
 [[package]]
 name = "utf8_iter"
 version = "1.0.4"
@@ -5731,6 +5885,7 @@ dependencies = [
  "chrono",
  "clipboard-win",
  "craft-print",
+ "craft-update",
  "craft-window",
  "eframe",
  "egui",
@@ -6191,6 +6346,7 @@ dependencies = [
  "bytemuck",
  "craft-keymap",
  "craft-ui",
+ "craft-update",
  "egui",
  "egui_extras",
  "egui_kittest",
@@ -6273,6 +6429,16 @@ dependencies = [
  "vello_common",
 ]
 
+[[package]]
+name = "verifysign"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6acfcc42a8d44f340d001193d97ef56bf33210b51ad760ae8308c97d5241ca51"
+dependencies = [
+ "core-foundation 0.10.1",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "version_check"
 version = "0.9.5"
@@ -6590,7 +6756,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "338e30461b3a2b67d70eb30a6d89f8e0c93a833e07d2ae89085cd070c4a00ac0"
 dependencies = [
  "proc-macro2",
- "quick-xml",
+ "quick-xml 0.41.0",
  "quote",
 ]
 
@@ -7142,6 +7308,16 @@ dependencies = [
  "xml",
 ]
 
+[[package]]
+name = "winreg"
+version = "0.55.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb5a765337c50e9ec252c2069be9bf91c7df47afb103b642ba3a53bf8101be97"
+dependencies = [
+ "cfg-if",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "winresource"
 version = "0.1.34"
@@ -7549,6 +7725,23 @@ dependencies = [
  "syn 3.0.9",
 ]
 
+[[package]]
+name = "zip"
+version = "9.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2886b00003a72c4ccee3f42cfc34908d33b2508a74d827dc2a4244706475c704"
+dependencies = [
+ "crc32fast",
+ "flate2",
+ "getrandom 0.4.3",
+ "indexmap",
+ "memchr",
+ "nix",
+ "typed-path",
+ "windows-sys 0.61.2",
+ "zopfli",
+]
+
 [[package]]
 name = "zlib-rs"
 version = "0.6.8"
@@ -7561,6 +7754,18 @@ version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "29666d0abbfad1e3dc4dcf6144730dd3a3ab225bbbdac83319345b1b44ccfc1b"
 
+[[package]]
+name = "zopfli"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aaf7fc5d30c28483d93805c4a5e12b05bbb52407fa67c5f8bd552374cd01fb11"
+dependencies = [
+ "bumpalo",
+ "crc32fast",
+ "log",
+ "simd-adler32",
+]
+
 [[package]]
 name = "zune-core"
 version = "0.5.3"
diff --git a/Cargo.toml b/Cargo.toml
index 87b78ec1b..39e208430 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,6 +19,7 @@ craft-keymap = { git = "https://github.com/storytold/craft-libs", rev = "a091680
 # Decides who draws the window frame (desktop vs. app) so the suite shares one native titlebar per
 # desktop. The `egui` feature adds `craft_window::decorate`. (craft-libs#217.)
 craft-window = { git = "https://github.com/storytold/craft-libs", rev = "a0916808f7d78bed8c7b90cdf937176015454a7f", features = ["egui"] }
+craft-update = { git = "https://github.com/storytold/craft-libs", version = "=0.1.0", rev = "db19c373c8d59a545972ca340987aecfb3611a4b", features = ["egui"] }
 # internal
 vectorcraft-geom = { path = "crates/geom" }
 vectorcraft-color = { path = "crates/color" }
diff --git a/apps/vectorcraft/Cargo.toml b/apps/vectorcraft/Cargo.toml
index 77b73a15a..3cfba6ee8 100644
--- a/apps/vectorcraft/Cargo.toml
+++ b/apps/vectorcraft/Cargo.toml
@@ -43,6 +43,7 @@ winit = { version = "0.30", default-features = false }
 craft-print = { workspace = true }
 
 [target.'cfg(windows)'.dependencies]
+craft-update = { workspace = true }
 clipboard-win = { workspace = true }
 # Which GPU drives which display (EnumDisplayDevices, src/gpu.rs), so the window is drawn on the
 # GPU that shows it: drawing on a GPU without a monitor reset the display driver. Safe wrappers over
diff --git a/apps/vectorcraft/src/main.rs b/apps/vectorcraft/src/main.rs
index e05792cec..d41c8bb72 100644
--- a/apps/vectorcraft/src/main.rs
+++ b/apps/vectorcraft/src/main.rs
@@ -813,6 +813,11 @@ Without a window (converting, scripting, the MCP server), use vectorcraft-cli:
 ";
 
 fn main() -> std::process::ExitCode {
+    // Windows: the update helper is a copy of this program started with `--finish-update`.
+    #[cfg(windows)]
+    if let Some(result) = craft_update::self_update::finish(&craft_update::suite::VECTORCRAFT, &std::env::args_os().skip(1).collect::<Vec<_>>()) {
+        std::process::exit(i32::from(result.is_err()));
+    }
     // Before any thread starts: the pointer must find a cursor theme on Wayland (#2450).
     #[cfg(target_os = "linux")]
     cursor_theme::apply();
@@ -1045,6 +1050,7 @@ fn main() -> std::process::ExitCode {
                 prefs_dir::attach_profile_store(&mut session);
                 prefs_dir::attach_plugin_store(&mut session);
                 let mut app = VectorcraftApp::new(session, services(cc.winit_window().cloned(), cc.egui_ctx.clone()));
+                app.set_startup_update_check(true);
                 load_prefs(&mut app, saved);
                 // The saved PDF presets live in their own folder (also read by vectorcraft-cli),
                 // which takes over from the copy the preferences file used to hold.
diff --git a/crates/ui-egui/Cargo.toml b/crates/ui-egui/Cargo.toml
index ad7e3d006..02de56a76 100644
--- a/crates/ui-egui/Cargo.toml
+++ b/crates/ui-egui/Cargo.toml
@@ -53,6 +53,7 @@ log = { workspace = true }
 # Floating panels open in OS windows of their own on the desktop; on the web they stay in the page.
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 craft-ui = { workspace = true, features = ["native-windows"] }
+craft-update = { workspace = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 # `now_ms` (src/lib.rs) reads the page's `performance.now()` with this crate in the web build. It is
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index ad5942358..440eb11ea 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -67,6 +67,7 @@ mod tools_float;
 pub mod touch;
 mod ui_fonts;
 pub mod unsaved;
+pub mod updates_ui;
 pub mod widgets;
 pub mod workspaces;
 
@@ -496,6 +497,7 @@ pub struct VectorcraftApp {
     ui_ctx: Option<egui::Context>,
     /// Installed fonts added to the UI's for characters its own fonts lack (CJK names…).
     ui_fonts: ui_fonts::UiFonts,
+    pub(crate) updates_rt: updates_ui::Runtime,
     /// The status bar's frame rate ([`frame_rate`]).
     frame_rate: frame_rate::FrameRate,
     /// Canvas rect of the last frame (screen points), for control-channel coordinate mapping.
@@ -802,6 +804,7 @@ impl VectorcraftApp {
             context: 0,
             ui_ctx: None,
             ui_fonts: Default::default(),
+            updates_rt: Default::default(),
             frame_rate: Default::default(),
             canvas_rect: None,
             hover_doc: None,
@@ -1748,6 +1751,7 @@ impl VectorcraftApp {
         let now = now_secs();
         self.perf.fps = self.frame_rate.frame(now, self.perf.frame_ms / 1000.0);
         self.sync_views();
+        updates_ui::tick(self, ctx);
         // Read the system clipboard only when that alone decides whether Paste is enabled. A
         // background thread reads it where the host installs one (an unresponsive owner must never
         // stall the frame loop); otherwise, or once that thread is gone, it is read here, at most a
@@ -2306,6 +2310,7 @@ impl VectorcraftApp {
         // The canvas and the panels: one docking layout. Tab hides the panels but not the canvas.
         egui::CentralPanel::default().frame(egui::Frame::NONE.fill(t.pasteboard)).show(ui, |ui| panel_docking::show(self, ui));
         dialogs::show(self, &ctx);
+        updates_ui::show(self, &ctx);
         export_progress::show(self, &ctx);
         plugin_runs::show(self, &ctx);
         palette::show(self, &ctx);
diff --git a/crates/ui-egui/src/menus.rs b/crates/ui-egui/src/menus.rs
index 52f755a84..09da4fd7d 100644
--- a/crates/ui-egui/src/menus.rs
+++ b/crates/ui-egui/src/menus.rs
@@ -554,6 +554,7 @@ pub const UI_COMMANDS: &[(&str, &str, &str, &str)] = &[
         "{} opens the Save PDF dialog; with params = document.exportPdf options written to path (asked when missing; viewAfterSaving opens the file) → {path, bytes, warnings}",
     ),
     ("help.about", "About VectorCraft", "", "{}"),
+    ("help.checkForUpdates", "Check for Updates…", "", "{}"),
     ("help.commandPalette", "Search Commands…", "Cmd+Shift+/", "{}"),
     ("app.quit", "Quit VectorCraft", "Cmd+Q", "{}"),
     (
@@ -1679,6 +1680,7 @@ pub fn run_ui_command(app: &mut VectorcraftApp, id: &str, p: &Value) -> Option<R
             app.ui.about = true;
             Ok(Value::Null)
         }
+        "help.checkForUpdates" => crate::updates_ui::check(app),
         "help.commandPalette" => {
             app.ui.palette_open = !app.ui.palette_open;
             app.ui.palette_query.clear();
@@ -3223,6 +3225,7 @@ pub fn menu_tree_named(english_names: bool) -> Vec<(&'static str, Vec<Item>)> {
                 c("Search Commands…", "help.commandPalette"),
                 todos("VectorCraft Help…", "F1"),
                 Sep,
+                c("Check for Updates…", "help.checkForUpdates"),
                 c("About VectorCraft", "help.about"),
             ],
         ),
diff --git a/crates/ui-egui/src/updates_ui.rs b/crates/ui-egui/src/updates_ui.rs
new file mode 100644
index 000000000..88e6b84a6
--- /dev/null
+++ b/crates/ui-egui/src/updates_ui.rs
@@ -0,0 +1,171 @@
+//! Software updates, background check at startup, and startup prompt modal.
+
+use serde_json::Value;
+
+use crate::VectorcraftApp;
+
+#[cfg(not(target_arch = "wasm32"))]
+use craft_update::updater::{Action, Status, Updater};
+
+pub(crate) struct Runtime {
+    #[cfg(not(target_arch = "wasm32"))]
+    updater: Updater,
+    /// The desktop app turns the check at start on; tests and the web build leave it off.
+    #[cfg(not(target_arch = "wasm32"))]
+    startup_check: bool,
+    #[cfg(not(target_arch = "wasm32"))]
+    check_requested: bool,
+    /// The context of the last frame, to wake the UI when a check is queued from a menu callback.
+    #[cfg(not(target_arch = "wasm32"))]
+    repaint: Option<egui::Context>,
+    pub(crate) manual_window_open: bool,
+    pub(crate) status_message: Option<String>,
+}
+
+impl Default for Runtime {
+    fn default() -> Self {
+        Self {
+            #[cfg(not(target_arch = "wasm32"))]
+            updater: Updater::new(&craft_update::suite::VECTORCRAFT, env!("CARGO_PKG_VERSION")),
+            #[cfg(not(target_arch = "wasm32"))]
+            startup_check: false,
+            #[cfg(not(target_arch = "wasm32"))]
+            check_requested: false,
+            #[cfg(not(target_arch = "wasm32"))]
+            repaint: None,
+            manual_window_open: false,
+            status_message: None,
+        }
+    }
+}
+
+impl VectorcraftApp {
+    /// Whether the app asks for a newer release when it starts (off until the desktop app turns it on).
+    #[cfg(not(target_arch = "wasm32"))]
+    pub fn set_startup_update_check(&mut self, on: bool) {
+        self.updates_rt.startup_check = on;
+    }
+}
+
+pub(crate) fn check(app: &mut VectorcraftApp) -> Result<Value, String> {
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        app.updates_rt.check_requested = true;
+        if let Some(ctx) = &app.updates_rt.repaint {
+            ctx.request_repaint();
+        }
+        Ok(Value::Null)
+    }
+    #[cfg(target_arch = "wasm32")]
+    {
+        app.updates_rt.manual_window_open = true;
+        app.updates_rt.status_message = Some("Update check is not supported in the web browser.".into());
+        Ok(Value::Null)
+    }
+}
+
+pub(crate) fn tick(app: &mut VectorcraftApp, ctx: &egui::Context) {
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        let rt = &mut app.updates_rt;
+        rt.repaint = Some(ctx.clone());
+        if std::mem::take(&mut rt.check_requested) {
+            rt.updater.check_now(ctx);
+        } else if rt.startup_check {
+            rt.updater.check_at_start(ctx);
+        }
+        rt.updater.tick(ctx);
+    }
+    #[cfg(target_arch = "wasm32")]
+    let _ = (app, ctx);
+}
+
+pub(crate) fn show(app: &mut VectorcraftApp, ctx: &egui::Context) {
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        // The restart helper is scheduled before the app closes, so no update starts over unsaved work.
+        let clean = !crate::unsaved::any_dirty(app);
+        match app.updates_rt.updater.show_if(ctx, clean) {
+            Action::OpenUrl(url) => app.open_url(&url),
+            Action::Close => ctx.send_viewport_cmd(egui::ViewportCommand::Close),
+            Action::None => {}
+        }
+        // The window answers Help ▸ Check for Updates, so it follows the updater's status.
+        let rt = &mut app.updates_rt;
+        (rt.manual_window_open, rt.status_message) = match rt.updater.status() {
+            Status::Idle => (false, None),
+            Status::Checking => (true, Some(tl!("Checking for updates…").to_string())),
+            Status::UpToDate => {
+                (true, Some(tl!("VectorCraft {version} is currently the newest version available.").replace("{version}", env!("CARGO_PKG_VERSION"))))
+            }
+            Status::Failed(e) => (true, Some(tl!("Could not check for updates:\n{error}").replace("{error}", e))),
+        };
+    }
+
+    if app.updates_rt.manual_window_open {
+        let mut open = true;
+        egui::Window::new(tl!("VectorCraft Updates"))
+            .open(&mut open)
+            .collapsible(false)
+            .resizable(false)
+            .pivot(egui::Align2::CENTER_CENTER)
+            .default_pos(ctx.content_rect().center())
+            .show(ctx, |ui| {
+                if let Some(msg) = &app.updates_rt.status_message {
+                    ui.label(msg);
+                }
+                ui.add_space(8.0);
+                if ui.button(tl!("OK")).clicked() {
+                    app.updates_rt.manual_window_open = false;
+                }
+            });
+        if !open {
+            app.updates_rt.manual_window_open = false;
+        }
+    }
+
+    // Closing the window dismisses the outcome it showed.
+    #[cfg(not(target_arch = "wasm32"))]
+    if !app.updates_rt.manual_window_open {
+        app.updates_rt.updater.dismiss_status();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use vectorcraft_engine::Session;
+
+    #[test]
+    fn default_runtime_is_idle() {
+        let rt = Runtime::default();
+        assert!(!rt.manual_window_open);
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            assert!(!rt.startup_check);
+            assert!(!rt.updater.prompt_open());
+            assert_eq!(rt.updater.status(), &Status::Idle);
+        }
+    }
+
+    #[test]
+    #[cfg(not(target_arch = "wasm32"))]
+    fn startup_prompt_shows_and_closes() {
+        let mut app = VectorcraftApp::new(Session::new(), Default::default());
+        let ctx = egui::Context::default();
+        let release = craft_update::Release {
+            tag: "v99.0.0".into(),
+            version: craft_update::parse_version("99.0.0"),
+            name: "VectorCraft 99.0.0".into(),
+            html_url: "https://github.com/storytold/vectorcraft/releases/tag/v99.0.0".into(),
+            ..Default::default()
+        };
+        app.updates_rt.updater.offer(release);
+
+        let mut output = ctx.run_ui(egui::RawInput::default(), |ui| {
+            show(&mut app, ui.ctx());
+        });
+        output.textures_delta.clear();
+        assert!(app.updates_rt.updater.prompt_open());
+    }
+}