Tray: devices window, bytes/packets toggle, copy & edit affordances

Replaces the in-tile collapsing peer list with a "Show devices" button that
opens a separate, normal-sized window per network, and fills in the rest of the
feedback.

Main window:
- A global show: pkts/bytes toggle; all rates and sparklines follow it.
- Sparklines now reserve their space always (fixed height, "no data yet"
  placeholder) so the layout no longer jumps when data arrives, and each one
  overlays its peak (top-left) and current value (bottom-right) with units.
- Device id has a copy button; the hostname is editable in place (✎ → edit →
  ✔/Enter sends SetHostname); network name, range and address copy on click.
- The Leave button is a neutral red. Per-tile "Show devices" opens the detail.

Devices window (a separate egui viewport per network):
- Network summary: id (copy), active/broadcast, range, this device's address,
  candidates, relay fwd/via/recv, dial/handshake failures.
- A larger network traffic sparkline.
- Connected peers in a table: hostname when known (else short key), protocol,
  address, handshake age formatted (s/m/h/d), tx/rx packets, tx/rx bytes, and
  current rate with an inline sparkline. Names and addresses copy on click.
- Offline members listed below with address and failed-dial count.

Agent: a SetHostname command (over the existing ipc) backs the in-place rename.
Traffic sampler now tracks both packet and byte rates; the toggle selects which.

Deferred: a "copy secret" button on the tile — the secret is deliberately not
exported to the GUI (secrets never leave the agent), so it needs a small local
secret-export ipc, which is the next step.

Builds and is clippy-clean (-D warnings) on macOS; the UI has not been run in
this headless session.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/tsunagi-tray/src/agent.rs

@@ -31,6 +31,8 @@ pub(crate) enum Command {
     Join { name: String, secret: String },
     /// Leave a network entirely.
     Leave { network_id: String },
+    /// Change the hostname this device announces.
+    SetHostname(String),
 }
 
 /// The latest the worker knows, read by the UI each frame.
@@ -166,6 +168,10 @@ async fn run(
             .await
             .map(|report| format!("left {}", report.name))
             .map_err(|err| err.to_string()),
+        Command::SetHostname(name) => ipc::set_hostname(socket, &name)
+            .await
+            .map(|accepted| format!("hostname: {accepted}"))
+            .map_err(|err| err.to_string()),
     };
 
     {

crates/tsunagi-tray/src/app.rs

@@ -1,26 +1,26 @@
-//! The eframe application: wires the tray, the window and the agent worker.
+//! The eframe application: wires the tray, the main window, the per-network
+//! devices windows, and the agent worker.
 
 use std::time::Duration;
 
 use eframe::egui;
 
 use crate::agent::{AgentClient, resolve_socket};
+use crate::devices;
 use crate::stats::Traffic;
 use crate::tray::{Action, Tray};
-use crate::ui::{self, JoinForm};
+use crate::ui::{self, UiState};
 
 /// The tray application state.
 pub(crate) struct App {
     agent: AgentClient,
     tray: Tray,
-    join: JoinForm,
+    state: UiState,
     /// Traffic rates derived from successive snapshots.
     traffic: Traffic,
-    /// The snapshot generation last folded into `traffic`, so each refresh is
+    /// The snapshot generation last folded into `traffic`.
-    /// sampled exactly once rather than on every repaint.
     sampled: u64,
-    /// Set when the user chose Quit, so the next close actually exits instead
+    /// Set when the user chose Quit, so the next close exits rather than hides.
-    /// of hiding to the tray.
     quitting: bool,
 }
 
@@ -36,7 +36,7 @@ impl App {
         Ok(Self {
             agent,
             tray,
-            join: JoinForm::default(),
+            state: UiState::default(),
             traffic: Traffic::default(),
             sampled: 0,
             quitting: false,
@@ -59,24 +59,56 @@ impl eframe::App for App {
             }
         }
 
-        // Closing the window hides it to the tray; only Quit truly exits.
+        // Closing the main window hides it to the tray; only Quit truly exits.
         if ctx.input(|i| i.viewport().close_requested()) && !self.quitting {
             ctx.send_viewport_cmd(egui::ViewportCommand::CancelClose);
             ctx.send_viewport_cmd(egui::ViewportCommand::Visible(false));
         }
 
         let snapshot = self.agent.snapshot();
-        // Fold each fresh status into the traffic rates exactly once.
         if snapshot.generation != self.sampled
             && let (Some(Ok(report)), Some(at)) = (&snapshot.status, snapshot.at)
         {
             self.traffic.observe(report, at);
             self.sampled = snapshot.generation;
         }
-        ui::draw(ctx, &self.agent, &mut self.join, &snapshot, &self.traffic);
 
-        // Keep ticking so fresh status and tray actions are picked up even when
+        ui::draw(ctx, &self.agent, &mut self.state, &snapshot, &self.traffic);
-        // nothing else requests a repaint.
+        self.show_devices_windows(ctx, &snapshot);
+
+        // Keep ticking so fresh status and tray actions are picked up.
         ctx.request_repaint_after(Duration::from_millis(500));
     }
 }
+
+impl App {
+    /// Renders one separate window per open network-devices view.
+    fn show_devices_windows(&mut self, ctx: &egui::Context, snapshot: &crate::agent::Snapshot) {
+        let Some(Ok(report)) = &snapshot.status else {
+            return;
+        };
+        let unit = self.state.unit;
+        let open: Vec<String> = self.state.open_devices.iter().cloned().collect();
+        for id in open {
+            let Some(network) = report.networks.iter().find(|n| n.network_id == id) else {
+                // The network is gone (left/forgotten); close its window.
+                self.state.open_devices.remove(&id);
+                continue;
+            };
+            let viewport_id = egui::ViewportId::from_hash_of(("devices", &id));
+            let builder = egui::ViewportBuilder::default()
+                .with_title(devices::title(network))
+                .with_inner_size([720.0, 540.0])
+                .with_min_inner_size([480.0, 320.0]);
+            let agent = &self.agent;
+            let traffic = &self.traffic;
+            let keep = ctx.show_viewport_immediate(viewport_id, builder, |vctx, _class| {
+                devices::show(vctx, agent, unit, network, traffic);
+                !vctx.input(|i| i.viewport().close_requested())
+            });
+            if !keep {
+                self.state.open_devices.remove(&id);
+            }
+        }
+    }
+}

crates/tsunagi-tray/src/devices.rs

@@ -0,0 +1,221 @@
+//! The per-network devices window: full detail about one network — its
+//! settings and counters, every connected peer in a table with an inline
+//! traffic plot, and the members that are currently offline below.
+//!
+//! Rendered in a separate OS window (an egui viewport) opened from a tile in
+//! the main window.
+
+use std::collections::HashMap;
+
+use eframe::egui;
+
+use tsunagi::ipc::NetworkReport;
+
+use crate::agent::AgentClient;
+use crate::format;
+use crate::stats::{Traffic, Unit};
+
+/// A readable title for a network's window.
+pub(crate) fn title(network: &NetworkReport) -> String {
+    format!("tsunagi · {}", network.name)
+}
+
+/// Draws the window body into its viewport.
+pub(crate) fn show(
+    ctx: &egui::Context,
+    _agent: &AgentClient,
+    unit: Unit,
+    network: &NetworkReport,
+    traffic: &Traffic,
+) {
+    egui::CentralPanel::default().show(ctx, |ui| {
+        ui.heading(&network.name);
+        summary(ui, network);
+        ui.add_space(6.0);
+
+        ui.label(egui::RichText::new("traffic").strong());
+        format::sparkline(ui, traffic.network(&network.network_id), unit, 48.0);
+        ui.add_space(8.0);
+
+        let hostnames: HashMap<&str, &str> = network
+            .peers
+            .iter()
+            .filter_map(|p| p.hostname.as_deref().map(|h| (p.endpoint_id.as_str(), h)))
+            .collect();
+
+        let overlay = network.overlay.as_ref();
+        let online = overlay.map(|o| o.peers.as_slice()).unwrap_or(&[]);
+
+        ui.label(egui::RichText::new(format!("connected peers ({})", online.len())).strong());
+        egui::ScrollArea::vertical()
+            .max_height(260.0)
+            .auto_shrink([false, false])
+            .show(ui, |ui| {
+                connected_table(ui, unit, &network.network_id, online, &hostnames, traffic);
+            });
+
+        // Members with no live tunnel right now.
+        let online_ids: std::collections::HashSet<&str> =
+            online.iter().map(|p| p.endpoint_id.as_str()).collect();
+        let offline: Vec<_> = network
+            .members
+            .iter()
+            .filter(|m| !online_ids.contains(m.endpoint_id.as_str()))
+            .collect();
+        if !offline.is_empty() {
+            ui.add_space(8.0);
+            ui.label(egui::RichText::new(format!("offline members ({})", offline.len())).strong());
+            offline_table(ui, &offline, &hostnames);
+        }
+    });
+}
+
+/// The network's own settings and counters.
+fn summary(ui: &mut egui::Ui, network: &NetworkReport) {
+    egui::Grid::new("summary")
+        .num_columns(2)
+        .spacing([12.0, 3.0])
+        .show(ui, |ui| {
+            ui.weak("id");
+            ui.horizontal(|ui| {
+                ui.monospace(&network.network_id);
+                format::copy_button(ui, &network.network_id);
+            });
+            ui.end_row();
+
+            ui.weak("active");
+            ui.label(yes_no(network.active));
+            ui.end_row();
+            ui.weak("broadcast");
+            ui.label(yes_no(network.broadcast));
+            ui.end_row();
+
+            if let Some(range) = &network.range {
+                ui.weak("range");
+                format::copy_label(ui, range, range);
+                ui.end_row();
+            }
+            if let Some(address) = network.overlay.as_ref().and_then(|o| o.address.as_ref()) {
+                ui.weak("this device");
+                format::copy_label(ui, address, address);
+                ui.end_row();
+            }
+            ui.weak("candidates");
+            ui.label(network.candidates.to_string());
+            ui.end_row();
+            ui.weak("relay fwd/via/recv");
+            ui.label(format!(
+                "{} / {} / {}",
+                network.relay_forwarded, network.relay_sent_via, network.relay_received_via
+            ));
+            ui.end_row();
+            ui.weak("dial/handshake fails");
+            ui.label(format!(
+                "{} / {}",
+                network.dial_failures, network.handshake_failures
+            ));
+            ui.end_row();
+        });
+}
+
+/// The table of peers with a live tunnel.
+fn connected_table(
+    ui: &mut egui::Ui,
+    unit: Unit,
+    network_id: &str,
+    peers: &[tsunagi::ipc::OverlayPeerReport],
+    hostnames: &HashMap<&str, &str>,
+    traffic: &Traffic,
+) {
+    if peers.is_empty() {
+        ui.weak("none");
+        return;
+    }
+    egui::Grid::new("connected")
+        .num_columns(7)
+        .striped(true)
+        .spacing([10.0, 4.0])
+        .show(ui, |ui| {
+            for header in [
+                "peer",
+                "proto",
+                "address",
+                "handshake",
+                "pkts",
+                "bytes",
+                "rate / plot",
+            ] {
+                ui.weak(header);
+            }
+            ui.end_row();
+
+            for peer in peers {
+                let name = hostnames
+                    .get(peer.endpoint_id.as_str())
+                    .map_or_else(|| format::short(&peer.public_key), |h| (*h).to_string());
+                format::copy_label(ui, &name, &name);
+                ui.label(&peer.protocol);
+                match &peer.address {
+                    Some(address) => format::copy_label(ui, address, address),
+                    None => {
+                        ui.weak("—");
+                    }
+                }
+                ui.label(
+                    peer.handshake_secs_ago
+                        .map_or_else(|| "never".to_string(), format::age),
+                );
+                ui.label(format!("{}/{}", peer.tx_packets, peer.rx_packets));
+                ui.label(format!(
+                    "{} / {}",
+                    format::bytes(peer.tx_bytes as f64),
+                    format::bytes(peer.rx_bytes as f64)
+                ));
+                let series = traffic.peer(network_id, &peer.public_key);
+                ui.horizontal(|ui| {
+                    ui.label(format::series_rate(series, unit));
+                    ui.allocate_ui(egui::vec2(90.0, 20.0), |ui| {
+                        format::sparkline(ui, series, unit, 18.0);
+                    });
+                });
+                ui.end_row();
+            }
+        });
+}
+
+/// The table of members with no current tunnel.
+fn offline_table(
+    ui: &mut egui::Ui,
+    members: &[&tsunagi::ipc::MemberReport],
+    hostnames: &HashMap<&str, &str>,
+) {
+    egui::Grid::new("offline")
+        .num_columns(3)
+        .striped(true)
+        .spacing([10.0, 4.0])
+        .show(ui, |ui| {
+            for header in ["member", "address", "failed dials"] {
+                ui.weak(header);
+            }
+            ui.end_row();
+
+            for member in members {
+                let name = hostnames
+                    .get(member.endpoint_id.as_str())
+                    .map_or_else(|| format::short(&member.endpoint_id), |h| (*h).to_string());
+                format::copy_label(ui, &name, &member.endpoint_id);
+                ui.label(
+                    member
+                        .overlay_address_v4
+                        .clone()
+                        .unwrap_or_else(|| "—".into()),
+                );
+                ui.label(member.failed_dials.to_string());
+                ui.end_row();
+            }
+        });
+}
+
+fn yes_no(value: bool) -> &'static str {
+    if value { "yes" } else { "no" }
+}

crates/tsunagi-tray/src/format.rs

@@ -0,0 +1,144 @@
+//! Formatting and small shared widgets: humanized ages, byte sizes and rates,
+//! a fixed-size sparkline, and click-to-copy labels.
+
+use eframe::egui;
+
+use crate::stats::{Series, Unit};
+
+/// Sparkline accent.
+const ACCENT: egui::Color32 = egui::Color32::from_rgb(0x2f, 0x80, 0xd8);
+
+/// A short, readable prefix of a long identifier (char-safe, no panic).
+pub(crate) fn short(id: &str) -> String {
+    const KEEP: usize = 12;
+    if id.chars().count() <= KEEP {
+        id.to_string()
+    } else {
+        format!("{}…", id.chars().take(KEEP).collect::<String>())
+    }
+}
+
+/// A duration in seconds as a compact age (`5s`, `12m`, `3h 20m`, `2d 4h`).
+pub(crate) fn age(secs: u64) -> String {
+    if secs < 60 {
+        format!("{secs}s")
+    } else if secs < 3_600 {
+        format!("{}m", secs / 60)
+    } else if secs < 86_400 {
+        format!("{}h {}m", secs / 3_600, (secs % 3_600) / 60)
+    } else {
+        format!("{}d {}h", secs / 86_400, (secs % 86_400) / 3_600)
+    }
+}
+
+/// A byte count in binary units.
+pub(crate) fn bytes(n: f64) -> String {
+    const UNITS: [&str; 5] = ["B", "kB", "MB", "GB", "TB"];
+    let mut value = n.max(0.0);
+    let mut unit = 0;
+    while value >= 1024.0 && unit < UNITS.len() - 1 {
+        value /= 1024.0;
+        unit += 1;
+    }
+    if unit == 0 {
+        format!("{} B", value as u64)
+    } else {
+        format!("{value:.1} {}", UNITS[unit])
+    }
+}
+
+/// A rate in the chosen unit, per second.
+pub(crate) fn rate(value: f32, unit: Unit) -> String {
+    match unit {
+        Unit::Packets => {
+            if value >= 1000.0 {
+                format!("{:.1}k pkt/s", value / 1000.0)
+            } else {
+                format!("{value:.0} pkt/s")
+            }
+        }
+        Unit::Bytes => format!("{}/s", bytes(f64::from(value))),
+    }
+}
+
+/// A fixed-height sparkline of a series' recent rate, with the peak (top-left)
+/// and current value (bottom-right) overlaid. The space is always reserved —
+/// even with no data — so the layout never jumps when data arrives.
+pub(crate) fn sparkline(ui: &mut egui::Ui, series: Option<&Series>, unit: Unit, height: f32) {
+    let width = ui.available_width();
+    let (rect, _) = ui.allocate_exact_size(egui::vec2(width, height), egui::Sense::hover());
+    let painter = ui.painter_at(rect);
+    let visuals = ui.visuals();
+    painter.rect_filled(rect, 2.0, visuals.extreme_bg_color);
+
+    let Some(series) = series else {
+        painter.text(
+            rect.center(),
+            egui::Align2::CENTER_CENTER,
+            "no data yet",
+            egui::FontId::proportional(10.0),
+            visuals.weak_text_color(),
+        );
+        return;
+    };
+
+    let history = series.history(unit);
+    let peak = history.iter().copied().fold(1.0_f32, f32::max);
+    if history.len() >= 2 {
+        let count = history.len();
+        let points: Vec<egui::Pos2> = history
+            .iter()
+            .enumerate()
+            .map(|(i, value)| {
+                let x = rect.left() + rect.width() * (i as f32 / (count - 1) as f32);
+                let y = rect.bottom() - 2.0 - (rect.height() - 12.0) * (value / peak);
+                egui::pos2(x, y)
+            })
+            .collect();
+        painter.add(egui::Shape::line(
+            points,
+            egui::Stroke::new(1.5_f32, ACCENT),
+        ));
+    }
+
+    painter.text(
+        rect.left_top() + egui::vec2(4.0, 2.0),
+        egui::Align2::LEFT_TOP,
+        format!("peak {}", rate(peak, unit)),
+        egui::FontId::proportional(9.0),
+        visuals.weak_text_color(),
+    );
+    painter.text(
+        rect.right_bottom() + egui::vec2(-4.0, -2.0),
+        egui::Align2::RIGHT_BOTTOM,
+        rate(series.rate(unit), unit),
+        egui::FontId::proportional(10.0),
+        visuals.strong_text_color(),
+    );
+}
+
+/// A label that copies `value` to the clipboard when clicked.
+pub(crate) fn copy_label(ui: &mut egui::Ui, display: &str, value: &str) {
+    let response = ui
+        .add(egui::Label::new(display).sense(egui::Sense::click()))
+        .on_hover_text("click to copy");
+    if response.clicked() {
+        ui.ctx().copy_text(value.to_owned());
+    }
+}
+
+/// A tiny clipboard button that copies `value`.
+pub(crate) fn copy_button(ui: &mut egui::Ui, value: &str) {
+    if ui
+        .small_button("⧉")
+        .on_hover_text("copy to clipboard")
+        .clicked()
+    {
+        ui.ctx().copy_text(value.to_owned());
+    }
+}
+
+/// The current rate of a series as a string, or a dash when unsampled.
+pub(crate) fn series_rate(series: Option<&Series>, unit: Unit) -> String {
+    series.map_or_else(|| "—".to_string(), |s| rate(s.rate(unit), unit))
+}

crates/tsunagi-tray/src/main.rs

@@ -11,6 +11,8 @@
 
 mod agent;
 mod app;
+mod devices;
+mod format;
 mod stats;
 mod tray;
 mod ui;

crates/tsunagi-tray/src/stats.rs

@@ -1,9 +1,10 @@
 //! Traffic rates derived from successive status snapshots.
 //!
-//! The agent reports cumulative packet counters, not rates. The GUI samples
+//! The agent reports cumulative packet and byte counters, not rates. The GUI
-//! them each time a fresh snapshot arrives and turns the deltas into a
+//! samples them each time a fresh snapshot arrives and turns the deltas into
-//! packets-per-second rate plus a short rolling history for a sparkline. One
+//! per-second rates plus short rolling histories for sparklines. One series per
-//! series per key: a network total, and each peer within it.
+//! key: a network total, and each peer within it. Both packets and bytes are
+//! tracked so the UI can switch between them.
 
 use std::collections::{HashMap, VecDeque};
 use std::time::Instant;
@@ -11,32 +12,62 @@ use std::time::Instant;
 use tsunagi::ipc::StatusReport;
 
 /// How many rate samples to keep for a sparkline.
-const HISTORY: usize = 48;
+const HISTORY: usize = 60;
 
-/// One series' rolling rate.
+/// Which quantity a rate or history is of.
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub(crate) enum Unit {
+    /// Packets per second.
+    Packets,
+    /// Bytes per second.
+    Bytes,
+}
+
+/// One series' rolling packet and byte rates.
 #[derive(Default)]
 pub(crate) struct Series {
-    last: Option<(Instant, u64)>,
+    last: Option<(Instant, u64, u64)>,
-    /// Most recent packets-per-second (tx + rx).
+    packets_rate: f32,
-    pub rate: f32,
+    bytes_rate: f32,
-    /// Recent rates, oldest first, for a sparkline.
+    packets_history: VecDeque<f32>,
-    pub history: VecDeque<f32>,
+    bytes_history: VecDeque<f32>,
 }
 
 impl Series {
-    fn sample(&mut self, now: Instant, total: u64) {
+    fn sample(&mut self, now: Instant, packets: u64, bytes: u64) {
-        if let Some((then, previous)) = self.last {
+        if let Some((then, prev_packets, prev_bytes)) = self.last {
             let dt = now.saturating_duration_since(then).as_secs_f32();
             if dt > 0.0 {
-                let delta = total.saturating_sub(previous) as f32;
+                self.packets_rate = packets.saturating_sub(prev_packets) as f32 / dt;
-                self.rate = delta / dt;
+                self.bytes_rate = bytes.saturating_sub(prev_bytes) as f32 / dt;
-                self.history.push_back(self.rate);
+                push(&mut self.packets_history, self.packets_rate);
-                while self.history.len() > HISTORY {
+                push(&mut self.bytes_history, self.bytes_rate);
-                    self.history.pop_front();
-                }
             }
         }
-        self.last = Some((now, total));
+        self.last = Some((now, packets, bytes));
+    }
+
+    /// The current rate in the chosen unit.
+    pub(crate) fn rate(&self, unit: Unit) -> f32 {
+        match unit {
+            Unit::Packets => self.packets_rate,
+            Unit::Bytes => self.bytes_rate,
+        }
+    }
+
+    /// The rolling history in the chosen unit.
+    pub(crate) fn history(&self, unit: Unit) -> &VecDeque<f32> {
+        match unit {
+            Unit::Packets => &self.packets_history,
+            Unit::Bytes => &self.bytes_history,
+        }
+    }
+}
+
+fn push(history: &mut VecDeque<f32>, value: f32) {
+    history.push_back(value);
+    while history.len() > HISTORY {
+        history.pop_front();
     }
 }
 
@@ -53,19 +84,21 @@ impl Traffic {
             let Some(overlay) = &network.overlay else {
                 continue;
             };
-            let mut net_total = 0u64;
+            let (mut net_packets, mut net_bytes) = (0u64, 0u64);
             for peer in &overlay.peers {
-                let total = peer.tx_packets.saturating_add(peer.rx_packets);
+                let packets = peer.tx_packets.saturating_add(peer.rx_packets);
-                net_total = net_total.saturating_add(total);
+                let bytes = peer.tx_bytes.saturating_add(peer.rx_bytes);
+                net_packets = net_packets.saturating_add(packets);
+                net_bytes = net_bytes.saturating_add(bytes);
                 self.series
                     .entry(peer_key(&network.network_id, &peer.public_key))
                     .or_default()
-                    .sample(now, total);
+                    .sample(now, packets, bytes);
             }
             self.series
                 .entry(net_key(&network.network_id))
                 .or_default()
-                .sample(now, net_total);
+                .sample(now, net_packets, net_bytes);
         }
     }
 

crates/tsunagi-tray/src/ui.rs

@@ -1,40 +1,61 @@
-//! The window contents, drawn from the latest agent snapshot.
+//! The main window: a compact overview. Per-network detail (the full peer
+//! table with inline plots) lives in a separate devices window (see
+//! [`crate::devices`]), opened from each tile.
 //!
-//! Pure rendering: state comes from the snapshot and the traffic sampler, and a
+//! Pure rendering: state comes from the snapshot and the traffic sampler, a
-//! change to a switch or a button sends a [`Command`] to the worker. The layout
+//! change to a switch or button sends a [`Command`] to the worker, and local UI
-//! targets one fixed, small window, so everything is laid out on a grid and the
+//! state (the join form, the unit toggle, which devices windows are open, an
-//! peer list hides behind a collapsing header.
+//! in-progress hostname edit) lives in [`UiState`].
 
-use std::collections::VecDeque;
+use std::collections::BTreeSet;
 
 use eframe::egui;
 
-use tsunagi::identity::NetworkSecret;
+use tsunagi::ipc::{NetworkReport, StatusReport};
-use tsunagi::ipc::{NetworkReport, OverlayPeerReport, StatusReport};
 
 use crate::agent::{AgentClient, Command, Snapshot};
-use crate::stats::Traffic;
+use crate::format;
+use crate::stats::{Traffic, Unit};
 
-/// Width of the value column's input fields, so name and secret line up.
-const INPUT_WIDTH: f32 = 208.0;
-/// Accent used for the traffic sparkline.
-const ACCENT: egui::Color32 = egui::Color32::from_rgb(0x2f, 0x80, 0xd8);
 const OK: egui::Color32 = egui::Color32::from_rgb(0x3c, 0xb0, 0x4a);
-const WARN: egui::Color32 = egui::Color32::from_rgb(0xd9, 0x9a, 0x00);
 const BAD: egui::Color32 = egui::Color32::from_rgb(0xd0, 0x4a, 0x3c);
+/// A neutral, not-garish red for the Leave button.
+const LEAVE_RED: egui::Color32 = egui::Color32::from_rgb(0xa8, 0x3a, 0x3a);
 
-/// Join form state, kept across frames.
+/// Join form fields.
 #[derive(Default)]
 pub(crate) struct JoinForm {
     pub(crate) name: String,
     pub(crate) secret: String,
 }
 
-/// Draws the whole window.
+/// Local UI state kept across frames.
+pub(crate) struct UiState {
+    pub(crate) join: JoinForm,
+    /// Whether rates and sparklines are shown in packets or bytes.
+    pub(crate) unit: Unit,
+    /// An in-progress hostname edit (`None` when not editing).
+    pub(crate) host_edit: Option<String>,
+    /// Network ids whose devices window is open.
+    pub(crate) open_devices: BTreeSet<String>,
+}
+
+impl Default for UiState {
+    fn default() -> Self {
+        Self {
+            join: JoinForm::default(),
+            unit: Unit::Packets,
+            host_edit: None,
+            open_devices: BTreeSet::new(),
+        }
+    }
+}
+
+/// Draws the main window.
 pub(crate) fn draw(
     ctx: &egui::Context,
     agent: &AgentClient,
-    join: &mut JoinForm,
+    state: &mut UiState,
     snapshot: &Snapshot,
     traffic: &Traffic,
 ) {
@@ -49,6 +70,10 @@ pub(crate) fn draw(
                 if snapshot.busy {
                     ui.add(egui::Spinner::new());
                 }
+                ui.separator();
+                ui.selectable_value(&mut state.unit, Unit::Bytes, "bytes");
+                ui.selectable_value(&mut state.unit, Unit::Packets, "pkts");
+                ui.label("show:");
             });
         });
         ui.add_space(4.0);
@@ -63,7 +88,7 @@ pub(crate) fn draw(
             };
         }
         ui.add_space(4.0);
-        draw_join(ui, agent, join);
+        draw_join(ui, agent, &mut state.join);
         ui.add_space(4.0);
     });
 
@@ -74,7 +99,7 @@ pub(crate) fn draw(
         }
         Some(Err(error)) => draw_unreachable(ui, agent, error),
         Some(Ok(report)) => {
-            draw_header(ui, report);
+            draw_header(ui, agent, state, report);
             ui.separator();
             egui::ScrollArea::vertical()
                 .auto_shrink([false, false])
@@ -84,19 +109,22 @@ pub(crate) fn draw(
                         ui.weak("No networks yet — join one below.");
                     }
                     for network in &report.networks {
-                        draw_network(ui, agent, traffic, network);
+                        draw_network(ui, agent, state, traffic, network);
                     }
                 });
         }
     });
 }
 
-/// The "agent cannot be reached" state, naming the socket it tried.
+/// The "agent cannot be reached" state.
 fn draw_unreachable(ui: &mut egui::Ui, agent: &AgentClient, error: &str) {
     ui.add_space(8.0);
     ui.colored_label(BAD, "The agent is not reachable.");
     ui.add_space(6.0);
-    kv(ui, "socket", &agent.socket().display().to_string());
+    ui.horizontal(|ui| {
+        ui.weak("socket");
+        ui.monospace(agent.socket().display().to_string());
+    });
     ui.add_space(4.0);
     ui.weak(error);
     ui.add_space(6.0);
@@ -106,34 +134,66 @@ fn draw_unreachable(ui: &mut egui::Ui, agent: &AgentClient, error: &str) {
     );
 }
 
-/// The device line.
+/// The device header: id (with a copy button) and an editable hostname.
-fn draw_header(ui: &mut egui::Ui, report: &StatusReport) {
+fn draw_header(ui: &mut egui::Ui, agent: &AgentClient, state: &mut UiState, report: &StatusReport) {
     ui.add_space(4.0);
-    egui::Grid::new("device")
+    ui.horizontal(|ui| {
-        .num_columns(2)
+        ui.weak("device");
-        .spacing([10.0, 3.0])
+        ui.monospace(format::short(&report.endpoint_id));
-        .show(ui, |ui| {
+        format::copy_button(ui, &report.endpoint_id);
-            kv_row(ui, "device", &short(&report.endpoint_id));
+    });
-            kv_row(ui, "host", &report.hostname);
+
-        });
+    ui.horizontal(|ui| {
+        ui.weak("host");
+        match &mut state.host_edit {
+            None => {
+                ui.label(&report.hostname);
+                if ui.small_button("✎").on_hover_text("rename").clicked() {
+                    state.host_edit = Some(report.hostname.clone());
+                }
+            }
+            Some(buffer) => {
+                let response = ui.add(egui::TextEdit::singleline(buffer).desired_width(150.0));
+                let submit = (response.lost_focus()
+                    && ui.input(|i| i.key_pressed(egui::Key::Enter)))
+                    || ui.small_button("✔").clicked();
+                if submit {
+                    agent.send(Command::SetHostname(buffer.trim().to_string()));
+                    state.host_edit = None;
+                } else if ui.small_button("✕").clicked() {
+                    state.host_edit = None;
+                }
+            }
+        }
+    });
+
     if !report.cache_healthy {
-        ui.colored_label(WARN, "cache unavailable");
+        ui.colored_label(
+            egui::Color32::from_rgb(0xd9, 0x9a, 0x00),
+            "cache unavailable",
+        );
     }
 }
 
-/// One network tile.
+/// One compact network tile.
 fn draw_network(
     ui: &mut egui::Ui,
     agent: &AgentClient,
+    state: &mut UiState,
     traffic: &Traffic,
     network: &NetworkReport,
 ) {
     ui.add_space(6.0);
     egui::Frame::group(ui.style()).show(ui, |ui| {
         ui.horizontal(|ui| {
+            // The name copies on click.
             ui.strong(network.name.as_str());
+            format::copy_label(ui, "⧉", &network.name);
             ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
-                if ui.small_button("Leave").clicked() {
+                let leave =
+                    egui::Button::new(egui::RichText::new("Leave").color(egui::Color32::WHITE))
+                        .fill(LEAVE_RED);
+                if ui.add(leave).clicked() {
                     agent.send(Command::Leave {
                         network_id: network.network_id.clone(),
                     });
@@ -141,40 +201,40 @@ fn draw_network(
             });
         });
 
-        let overlay = network.overlay.as_ref();
+        let address = network.overlay.as_ref().and_then(|o| o.address.as_ref());
-        let address = overlay.and_then(|o| o.address.as_ref());
         let series = traffic.network(&network.network_id);
 
         egui::Grid::new(("net", &network.network_id))
             .num_columns(2)
             .spacing([10.0, 3.0])
             .show(ui, |ui| {
-                kv_row(ui, "id", &short(&network.network_id));
+                ui.weak("id");
+                ui.horizontal(|ui| {
+                    ui.label(format::short(&network.network_id));
+                    format::copy_button(ui, &network.network_id);
+                });
+                ui.end_row();
+
                 if let Some(range) = &network.range {
-                    kv_row(ui, "range", range);
+                    ui.weak("range");
+                    format::copy_label(ui, range, range);
+                    ui.end_row();
                 }
                 if let Some(address) = address {
-                    kv_row(ui, "addr", address);
+                    ui.weak("addr");
-                }
+                    format::copy_label(ui, address, address);
-                kv_row(
+                    ui.end_row();
-                    ui,
-                    "peers",
-                    &format!(
-                        "{} connected · {} known",
-                        network.peers.len(),
-                        network.members.len()
-                    ),
-                );
-                if let Some(series) = series {
-                    kv_row(ui, "traffic", &rate(series.rate));
                 }
+                ui.weak("peers");
+                ui.label(format!(
+                    "{} connected · {} known",
+                    network.peers.len(),
+                    network.members.len()
+                ));
+                ui.end_row();
             });
 
-        if let Some(series) = series
+        format::sparkline(ui, series, state.unit, 34.0);
-            && series.history.len() >= 2
-        {
-            sparkline(ui, &series.history);
-        }
 
         ui.horizontal(|ui| {
             let mut active = network.active;
@@ -191,51 +251,18 @@ fn draw_network(
                     enabled: broadcast,
                 });
             }
+            ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
+                if ui.button("Show devices").clicked() {
+                    state.open_devices.insert(network.network_id.clone());
+                }
+            });
         });
-
-        if let Some(overlay) = overlay
-            && !overlay.peers.is_empty()
-        {
-            egui::CollapsingHeader::new(format!("peers ({})", overlay.peers.len()))
-                .id_salt(("peers", &network.network_id))
-                .show(ui, |ui| {
-                    draw_peers(ui, traffic, &network.network_id, &overlay.peers);
-                });
-        }
     });
 }
 
-/// The per-peer table inside a network's collapsing header.
-fn draw_peers(ui: &mut egui::Ui, traffic: &Traffic, network_id: &str, peers: &[OverlayPeerReport]) {
-    egui::Grid::new(("peertable", network_id))
-        .num_columns(5)
-        .striped(true)
-        .spacing([10.0, 3.0])
-        .show(ui, |ui| {
-            for header in ["peer", "address", "age", "tx/rx", "rate"] {
-                ui.weak(header);
-            }
-            ui.end_row();
-
-            for peer in peers {
-                ui.monospace(short(&peer.public_key));
-                ui.label(peer.address.clone().unwrap_or_else(|| "—".into()));
-                ui.label(match peer.handshake_secs_ago {
-                    Some(secs) => format!("{secs}s"),
-                    None => "—".into(),
-                });
-                ui.label(format!("{}/{}", peer.tx_packets, peer.rx_packets));
-                let pps = traffic
-                    .peer(network_id, &peer.public_key)
-                    .map_or(0.0, |series| series.rate);
-                ui.label(rate(pps));
-                ui.end_row();
-            }
-        });
-}
-
 /// The join form: aligned name and secret, a generate button, and Join.
 fn draw_join(ui: &mut egui::Ui, agent: &AgentClient, join: &mut JoinForm) {
+    const INPUT_WIDTH: f32 = 208.0;
     ui.label("Join or create a network");
     egui::Grid::new("join")
         .num_columns(2)
@@ -257,7 +284,10 @@ fn draw_join(ui: &mut egui::Ui, agent: &AgentClient, join: &mut JoinForm) {
                     .on_hover_text("Generate a new random secret")
                     .clicked()
                 {
-                    join.secret = NetworkSecret::generate().encode().as_str().to_owned();
+                    join.secret = tsunagi::identity::NetworkSecret::generate()
+                        .encode()
+                        .as_str()
+                        .to_owned();
                 }
             });
             ui.end_row();
@@ -275,62 +305,3 @@ fn draw_join(ui: &mut egui::Ui, agent: &AgentClient, join: &mut JoinForm) {
         join.secret.clear();
     }
 }
-
-/// A small filled-ish line chart of recent rates, drawn with the painter.
-fn sparkline(ui: &mut egui::Ui, history: &VecDeque<f32>) {
-    let width = ui.available_width();
-    let (rect, _) = ui.allocate_exact_size(egui::vec2(width, 26.0), egui::Sense::hover());
-    let painter = ui.painter_at(rect);
-    let peak = history.iter().copied().fold(1.0_f32, f32::max);
-    let count = history.len();
-    if count < 2 {
-        return;
-    }
-    let points: Vec<egui::Pos2> = history
-        .iter()
-        .enumerate()
-        .map(|(i, value)| {
-            let x = rect.left() + rect.width() * (i as f32 / (count - 1) as f32);
-            let y = rect.bottom() - (rect.height() - 2.0) * (value / peak);
-            egui::pos2(x, y)
-        })
-        .collect();
-    painter.add(egui::Shape::line(
-        points,
-        egui::Stroke::new(1.5_f32, ACCENT),
-    ));
-}
-
-/// A key/value label pair outside a grid.
-fn kv(ui: &mut egui::Ui, key: &str, value: &str) {
-    ui.horizontal(|ui| {
-        ui.weak(key);
-        ui.monospace(value);
-    });
-}
-
-/// A key/value row inside a two-column grid.
-fn kv_row(ui: &mut egui::Ui, key: &str, value: &str) {
-    ui.weak(key);
-    ui.label(value);
-    ui.end_row();
-}
-
-/// Formats a packets-per-second rate.
-fn rate(pps: f32) -> String {
-    if pps >= 1000.0 {
-        format!("{:.1}k pkt/s", pps / 1000.0)
-    } else {
-        format!("{pps:.0} pkt/s")
-    }
-}
-
-/// A short, readable prefix of a long identifier (char-safe, no panic).
-fn short(id: &str) -> String {
-    const KEEP: usize = 12;
-    if id.chars().count() <= KEEP {
-        id.to_string()
-    } else {
-        format!("{}…", id.chars().take(KEEP).collect::<String>())
-    }
-}