diff --git a/fktry/src/ui/buildbar.ts b/fktry/src/ui/buildbar.ts
new file mode 100644
index 0000000..d5e9dc5
--- /dev/null
+++ b/fktry/src/ui/buildbar.ts
@@ -0,0 +1,75 @@
+/**
+ * LANE-UI — build bar. One button per machine in GameData.machines, hotkeys 1-9.
+ * Click or hotkey selects for placement; main.ts does the ghost and the actual place.
+ */
+import type { GameData } from '../contracts';
+import { attrs, cls, el, panel, text } from './dom';
+import { machineColor } from './palette';
+import type { BuildSelection } from './selection';
+import { COPY, DIR_NAME } from './voice';
+
+export interface BuildBar {
+  el: HTMLElement;
+  /** Select the machine in slot `n` (1-based, as printed on the button). */
+  selectSlot(n: number): void;
+  sync(): void;
+}
+
+export function createBuildBar(data: GameData, sel: BuildSelection): BuildBar {
+  const root = panel();
+  root.id = 'fk-build';
+
+  const row = el('div', 'fk-build-row');
+  const hint = el('div');
+  hint.id = 'fk-build-hint';
+
+  const buttons: Array<{ def: string; btn: HTMLButtonElement }> = [];
+
+  data.machines.forEach((m, i) => {
+    const btn = el('button', 'fk-build-btn');
+    attrs(btn, { type: 'button', title: `${m.name} — ${m.kind}` });
+
+    const ico = el('div', 'fk-build-ico');
+    ico.style.background = machineColor(m);
+    btn.append(ico);
+
+    // Only the first nine get a printed hotkey; the rest are click-only until the
+    // bar grows tabs/pages (a later round's problem).
+    if (i < 9) {
+      const key = el('span', 'fk-build-key');
+      key.textContent = String(i + 1);
+      btn.append(key);
+    }
+
+    btn.append(el('span', 'fk-build-name', [m.name]));
+    btn.addEventListener('click', () => sel.select(m.id));
+    row.append(btn);
+    buttons.push({ def: m.id, btn });
+  });
+
+  root.append(row, hint);
+
+  function sync() {
+    const cur = sel.get();
+    for (const b of buttons) cls(b.btn, 'is-sel', cur?.def === b.def);
+    if (cur) {
+      const def = data.machines.find((m) => m.id === cur.def);
+      text(hint, `${def?.name ?? cur.def} · FACING ${DIR_NAME[cur.dir]} · ${COPY.placingHint}`);
+    } else {
+      text(hint, COPY.idleHint);
+    }
+    cls(hint, 'is-placing', !!cur);
+  }
+
+  sel.onChange(sync);
+  sync();
+
+  return {
+    el: root,
+    selectSlot(n) {
+      const b = buttons[n - 1];
+      if (b) sel.select(b.def);
+    },
+    sync,
+  };
+}
diff --git a/fktry/src/ui/fax.ts b/fktry/src/ui/fax.ts
new file mode 100644
index 0000000..6b286d0
--- /dev/null
+++ b/fktry/src/ui/fax.ts
@@ -0,0 +1,70 @@
+/**
+ * LANE-UI — the commission fax. The fax machine is sacred, do not ask why it works
+ * (lore §6). Sits under THE SCREEN, top right.
+ *
+ * Progress comes from `snap.commissionProgress` (itemId -> count delivered), measured
+ * against the active CommissionDef's `wants`.
+ */
+import type { CommissionDef, GameData, ItemDef, SimSnapshot } from '../contracts';
+import { createChipRow, type ChipRow } from './chips';
+import { cls, el, panel, text } from './dom';
+import { COPY } from './voice';
+
+export interface Fax {
+  el: HTMLElement;
+  update(snap: SimSnapshot): void;
+  /** Play the stamp. Driven by the `commissionDone` event, not by progress math. */
+  stamp(): void;
+}
+
+const STAMP_MS = 1800; // must match the fk-stamp keyframes in style.ts
+
+export function createFax(data: GameData): Fax {
+  const commissions = new Map<string, CommissionDef>(data.commissions.map((c) => [c.id, c]));
+  const items = new Map<string, ItemDef>(data.items.map((i) => [i.id, i]));
+
+  const root = panel();
+  root.id = 'fk-fax';
+
+  const head = el('div', 'fk-h fk-fax-h', [COPY.faxHeader]);
+  const sub = el('div', 'fk-fax-sub', [COPY.faxSubheader]);
+  const flavor = el('div', 'fk-fax-flavor');
+  const chips: ChipRow = createChipRow(items);
+  const reward = el('div', 'fk-fax-sub');
+
+  const stampEl = el('div', 'fk-fax-stamp', [el('span', undefined, [COPY.faxStamp])]);
+
+  root.append(head, sub, flavor, el('div', 'fk-rule'), chips.el, reward, stampEl);
+
+  let stampTimer: number | undefined;
+
+  return {
+    el: root,
+    update(snap) {
+      const c = snap.activeCommission ? commissions.get(snap.activeCommission) : null;
+      cls(root, 'is-open', !!c);
+      if (!c) return;
+
+      text(flavor, c.flavor);
+      chips.update(
+        Object.entries(c.wants).map(([item, need]) => {
+          const have = snap.commissionProgress[item] ?? 0;
+          return {
+            item,
+            count: `${Math.min(have, need)}/${need}`,
+            state: have >= need ? ('met' as const) : ('plain' as const),
+          };
+        }),
+      );
+      text(reward, `ON RECEIPT: +${c.rewardBandwidth} BANDWIDTH`);
+    },
+    stamp() {
+      // Restart cleanly if two commissions complete back to back.
+      cls(stampEl, 'is-on', false);
+      void stampEl.offsetWidth; // force reflow so the animation re-runs
+      cls(stampEl, 'is-on', true);
+      clearTimeout(stampTimer);
+      stampTimer = setTimeout(() => cls(stampEl, 'is-on', false), STAMP_MS);
+    },
+  };
+}
diff --git a/fktry/src/ui/index.ts b/fktry/src/ui/index.ts
index f5bd503..7cd4147 100644
--- a/fktry/src/ui/index.ts
+++ b/fktry/src/ui/index.ts
@@ -1,17 +1,144 @@
-/** LANE-UI territory. Stub — replace per lanes/LANE-UI.md. */
-import type { GameData, SimEvent, SimSnapshot, UI, UIBus } from '../contracts';
+/**
+ * LANE-UI — HUD root. Everything DOM: build bar, top strip, inspector, fax, toasts.
+ *
+ * Rules of the house (CONTRACTS + LANE-UI.md):
+ *  - `#ui` is pointer-events:none; every interactive child re-enables it, so clicks fall
+ *    through to the world everywhere we haven't drawn a panel.
+ *  - We never mutate the snapshot and never hold a reference to it across frames.
+ *  - All mutation goes out as Commands on the bus.
+ */
+import type { GameData, MachineDef, SimEvent, SimSnapshot, UI, UIBus } from '../contracts';
+import { createBuildBar } from './buildbar';
+import { createFax } from './fax';
+import { createFixture, fixtureEnabled, type Fixture } from './fixture';
+import { createHotkeys } from './hotkeys';
+import { createInspector } from './inspector';
+import { createRoster, entityAt, resolvePickTile, syncRoster, type PickTile } from './pick';
+import { createSelection } from './selection';
+import { injectStyle } from './style';
+import { createTopStrip } from './topstrip';
+import { createToasts } from './toasts';
 
 export function createUI(): UI {
-  let tickEl: HTMLElement;
+  let machines = new Map<string, MachineDef>();
+  let top: ReturnType<typeof createTopStrip>;
+  let build: ReturnType<typeof createBuildBar>;
+  let inspector: ReturnType<typeof createInspector>;
+  let fax: ReturnType<typeof createFax>;
+  let toasts: ReturnType<typeof createToasts>;
+
+  let pickTile: PickTile | null = null;
+  let fixture: Fixture | null = null;
+
+  /** Our own copy of the entity list; safe to read between frames. See pick.ts. */
+  const roster = createRoster();
+  let paused = false;
+  let manifestIndex = -1;
+
+  function rosterIndexOf(id: number): number {
+    for (let i = 0; i < roster.length; i++) if (roster.entries[i].id === id) return i;
+    return -1;
+  }
+
+  function machineName(entityId: number): string {
+    const i = rosterIndexOf(entityId);
+    if (i < 0) return `UNIT ${entityId}`;
+    return machines.get(roster.entries[i].def)?.name ?? `UNIT ${entityId}`;
+  }
+
+  /**
+   * TEMPORARY: nothing reachable from the UI can turn a click into a tile (see pick.ts),
+   * so TAB walks the unit manifest instead. That keeps the inspector reachable with no
+   * console, which is the round's definition of done. Delete once the CONTRACT REQUEST
+   * for `UIBus.pickTile` lands and clicking a machine works.
+   */
+  function cycleManifest() {
+    if (roster.length === 0) return;
+    manifestIndex = (manifestIndex + 1) % roster.length;
+    inspector.open(roster.entries[manifestIndex].id);
+  }
+
   return {
-    init(root: HTMLElement, _data: GameData, _bus: UIBus) {
-      tickEl = document.createElement('div');
-      tickEl.style.cssText =
-        'position:fixed;bottom:8px;left:8px;color:#4a6b4a;font-size:12px;pointer-events:none';
-      root.appendChild(tickEl);
+    init(root: HTMLElement, data: GameData, bus: UIBus) {
+      injectStyle();
+      machines = new Map(data.machines.map((m) => [m.id, m]));
+
+      const sel = createSelection(bus);
+      top = createTopStrip(data);
+      build = createBuildBar(data, sel);
+      inspector = createInspector(data);
+      fax = createFax(data);
+      toasts = createToasts();
+
+      root.append(top.el, build.el, inspector.el, fax.el, toasts.el);
+
+      if (fixtureEnabled()) {
+        fixture = createFixture(data);
+        console.info('[ui] fixture mode: the HUD is being driven by a fake sim (?uifixture)');
+      }
+
+      // ------------------------------------------------------------------ keyboard
+      const keys = createHotkeys();
+      for (let n = 1; n <= 9; n++) keys.bind(String(n), () => build.selectSlot(n));
+      keys.bind('r', () => sel.rotate());
+      keys.bind('escape', () => {
+        // One key, two jobs, in the order the player expects: drop the tool first.
+        if (sel.get()) sel.clear();
+        else inspector.close();
+      });
+      keys.bind(' ', () => bus.dispatch({ kind: 'setPaused', paused: !paused }));
+      keys.bind('tab', cycleManifest);
+      keys.attach();
+
+      // ------------------------------------------------------------------- pointer
+      // main.ts owns click-to-place on #game. We handle only the two cases it doesn't:
+      // right-click cancels the pending build, and a plain left click with nothing
+      // selected inspects whatever unit is under the cursor.
+      const game = document.getElementById('game');
+      const inWorld = (t: EventTarget | null) => t instanceof Node && !!game?.contains(t);
+
+      addEventListener('contextmenu', (e) => {
+        if (!inWorld(e.target)) return;
+        e.preventDefault();
+        sel.clear();
+      });
+
+      addEventListener('pointerdown', (e) => {
+        if (e.button !== 0 || !inWorld(e.target)) return;
+        if (sel.get()) return; // placing, not inspecting — that click is main.ts's
+
+        pickTile ??= resolvePickTile(); // renderer may register late
+        const tile = pickTile?.(e.clientX, e.clientY);
+        if (!tile) return;
+
+        const hit = entityAt(roster, machines, tile);
+        if (hit === null) {
+          inspector.close();
+        } else {
+          inspector.open(hit);
+          manifestIndex = rosterIndexOf(hit);
+        }
+      });
     },
-    update(snap: SimSnapshot, _events: SimEvent[]) {
-      tickEl.textContent = `TICK ${snap.tick}`;
+
+    update(snap: SimSnapshot, events: SimEvent[]) {
+      if (fixture) {
+        snap = fixture.snapshot(snap.paused);
+        events = fixture.drain();
+      }
+
+      paused = snap.paused;
+      syncRoster(roster, snap);
+
+      top.update(snap);
+      inspector.update(snap);
+      fax.update(snap);
+
+      for (const ev of events) {
+        toasts.push(ev, machineName);
+        if (ev.kind === 'commissionDone') fax.stamp();
+      }
+      toasts.update(performance.now());
     },
   };
 }
diff --git a/fktry/src/ui/inspector.ts b/fktry/src/ui/inspector.ts
new file mode 100644
index 0000000..6ce8258
--- /dev/null
+++ b/fktry/src/ui/inspector.ts
@@ -0,0 +1,130 @@
+/**
+ * LANE-UI — inspector panel. Shows one entity: what it is, what the codex says about
+ * it, what it's chewing, how far along, and why it has stopped.
+ *
+ * Holds an entity *id*, never an entity object — CONTRACTS says the sim may reuse
+ * snapshot buffers between frames, so we re-look-up from the live snapshot each update
+ * and close ourselves if the unit is gone.
+ */
+import type { EntityState, GameData, ItemDef, MachineDef, RecipeDef, SimSnapshot } from '../contracts';
+import { createChipRow, type ChipRow, type ChipSpec } from './chips';
+import { attrs, cls, el, panel, style, text } from './dom';
+import { COPY, machineFlavor } from './voice';
+
+export interface Inspector {
+  el: HTMLElement;
+  open(entityId: number): void;
+  close(): void;
+  isOpen(): boolean;
+  update(snap: SimSnapshot): void;
+}
+
+export function createInspector(data: GameData): Inspector {
+  const machines = new Map<string, MachineDef>(data.machines.map((m) => [m.id, m]));
+  const recipes = new Map<string, RecipeDef>(data.recipes.map((r) => [r.id, r]));
+  const items = new Map<string, ItemDef>(data.items.map((i) => [i.id, i]));
+
+  const root = panel();
+  root.id = 'fk-inspect';
+
+  const name = el('div', 'fk-ins-name');
+  const closeBtn = el('button', 'fk-ins-x', [COPY.inspectorClose]);
+  attrs(closeBtn, { type: 'button', title: 'CLOSE (ESC)' });
+  const head = el('div', 'fk-ins-head', [name, closeBtn]);
+
+  const flavor = el('div', 'fk-ins-flavor');
+
+  const noRecipe = el('div', 'fk-ins-empty', [COPY.inspectorEmptyRecipe]);
+
+  const inHead = el('div', 'fk-h', [COPY.inspectorInput]);
+  const inChips: ChipRow = createChipRow(items);
+  const outHead = el('div', 'fk-h', [COPY.inspectorOutput]);
+  const outChips: ChipRow = createChipRow(items);
+
+  const progHead = el('div', 'fk-h', [COPY.inspectorProgress]);
+  const progFill = el('div', 'fk-bar-f');
+  const progBar = el('div', 'fk-bar', [progFill]);
+
+  const heatRow = el('div', 'fk-stat', [el('span', undefined, ['HEAT']), el('span', 'fk-stat-v')]);
+  const heatVal = heatRow.lastElementChild as HTMLElement;
+
+  const jam = el('div', 'fk-ins-jam');
+
+  const body = el('div', undefined, [
+    noRecipe, inHead, inChips.el, outHead, outChips.el, progHead, progBar, heatRow,
+  ]);
+
+  root.append(head, flavor, el('div', 'fk-rule'), body, jam);
+
+  let openId: number | null = null;
+
+  function close() {
+    openId = null;
+    cls(root, 'is-open', false);
+  }
+  closeBtn.addEventListener('click', close);
+
+  function paint(e: EntityState) {
+    const def = machines.get(e.def);
+    text(name, def?.name ?? e.def.toUpperCase());
+    text(flavor, machineFlavor(e.def));
+
+    const recipe = e.recipe ? recipes.get(e.recipe) : null;
+    const hasProcess = !!recipe;
+
+    style(noRecipe, 'display', hasProcess ? 'none' : 'block');
+    for (const n of [outHead, outChips.el, progHead, progBar]) {
+      style(n, 'display', hasProcess ? '' : 'none');
+    }
+
+    // Extractors take nothing from the world but the world itself — no INTAKE header
+    // for a machine that has no intake.
+    const hasInputs = !!recipe && Object.keys(recipe.inputs).length > 0;
+    for (const n of [inHead, inChips.el]) style(n, 'display', hasInputs ? '' : 'none');
+
+    if (recipe) {
+      const ins: ChipSpec[] = Object.entries(recipe.inputs).map(([item, need]) => {
+        const have = e.inputBuf[item] ?? 0;
+        return { item, count: `${have}/${need}`, state: have >= need ? 'met' : 'short' };
+      });
+      inChips.update(ins);
+
+      // Recipe outputs first, then anything else the buffer is holding (a jam is often
+      // an item the recipe never mentions).
+      const outIds = new Set(Object.keys(recipe.outputs));
+      for (const id of Object.keys(e.outputBuf)) outIds.add(id);
+      outChips.update(
+        [...outIds].map((item) => ({ item, count: String(e.outputBuf[item] ?? 0) })),
+      );
+
+      style(progFill, 'width', `${Math.max(0, Math.min(1, e.progress)) * 100}%`);
+    }
+
+    const hot = e.heat > 0.01;
+    style(heatRow, 'display', hot ? '' : 'none');
+    if (hot) {
+      text(heatVal, `${(e.heat * 100).toFixed(0)}%${e.heat > 0.7 ? ' · THROTTLING' : ''}`);
+      style(heatVal, 'color', e.heat > 0.7 ? 'var(--fk-red)' : 'var(--fk-amber)');
+    }
+
+    const jammed = !!e.jammed;
+    cls(jam, 'is-on', jammed);
+    if (jammed) text(jam, COPY.inspectorJamPrefix + e.jammed!.toUpperCase());
+  }
+
+  return {
+    el: root,
+    open(entityId) {
+      openId = entityId;
+      cls(root, 'is-open', true);
+    },
+    close,
+    isOpen: () => openId !== null,
+    update(snap) {
+      if (openId === null) return;
+      const e = snap.entities.find((x) => x.id === openId);
+      if (!e) return close(); // unit was removed out from under us
+      paint(e);
+    },
+  };
+}
diff --git a/fktry/src/ui/toasts.ts b/fktry/src/ui/toasts.ts
new file mode 100644
index 0000000..b39b525
--- /dev/null
+++ b/fktry/src/ui/toasts.ts
@@ -0,0 +1,49 @@
+/**
+ * LANE-UI — event toasts, bottom right. Max 4 on screen, 6s each, oldest evicted.
+ *
+ * Wall-clock timing is fine here: toasts are chrome, not sim. The determinism rule in
+ * MASTERPLAN binds `src/sim/**`, and nothing in this file feeds back into it.
+ */
+import type { SimEvent } from '../contracts';
+import { cls, el } from './dom';
+import { eventToast } from './voice';
+
+export interface Toasts {
+  el: HTMLElement;
+  push(ev: SimEvent, machineName: (entityId: number) => string): void;
+  /** Called once per frame to expire old lines. */
+  update(nowMs: number): void;
+}
+
+const TTL_MS = 6000;
+const FADE_MS = 400; // must match the .fk-toast.is-out transition
+const MAX = 4;
+
+export function createToasts(): Toasts {
+  const root = el('div');
+  root.id = 'fk-toasts';
+
+  const live: Array<{ node: HTMLElement; dieAt: number }> = [];
+
+  function retire(entry: { node: HTMLElement; dieAt: number }) {
+    cls(entry.node, 'is-out', true);
+    setTimeout(() => entry.node.remove(), FADE_MS);
+  }
+
+  return {
+    el: root,
+    push(ev, machineName) {
+      const msg = eventToast(ev, machineName);
+      if (!msg) return;
+
+      const node = el('div', `fk-toast k-${ev.kind}`, [msg]);
+      root.append(node);
+      live.push({ node, dieAt: performance.now() + TTL_MS });
+
+      while (live.length > MAX) retire(live.shift()!);
+    },
+    update(nowMs) {
+      while (live.length && live[0].dieAt <= nowMs) retire(live.shift()!);
+    },
+  };
+}
diff --git a/fktry/src/ui/topstrip.ts b/fktry/src/ui/topstrip.ts
new file mode 100644
index 0000000..e72ee86
--- /dev/null
+++ b/fktry/src/ui/topstrip.ts
@@ -0,0 +1,84 @@
+/**
+ * LANE-UI — top strip: bandwidth meter, shipped ticker, run state.
+ *
+ * The brownout has to be legible from this panel alone — it is the one failure the
+ * player must read across the room, so it gets the border, the color, and the flash.
+ */
+import type { GameData, ItemDef, SimSnapshot } from '../contracts';
+import { createChipRow, type ChipRow } from './chips';
+import { cls, el, panel, style, text } from './dom';
+import { COPY } from './voice';
+
+export interface TopStrip {
+  el: HTMLElement;
+  update(snap: SimSnapshot): void;
+}
+
+/** Draw above this fraction of generation is "tight" — amber, before it's a fault. */
+const TIGHT_AT = 0.85;
+
+function stat(label: string, valueCls?: string): { row: HTMLElement; v: HTMLElement } {
+  const v = el('span', valueCls ? `fk-stat-v ${valueCls}` : 'fk-stat-v');
+  const row = el('div', 'fk-stat', [el('span', undefined, [label]), v]);
+  return { row, v };
+}
+
+export function createTopStrip(data: GameData): TopStrip {
+  const root = panel();
+  root.id = 'fk-top';
+
+  const head = el('div', 'fk-h', [COPY.bandwidth]);
+
+  const drawEl = el('span', 'fk-bw-draw');
+  const genEl = el('span');
+  const nums = el('div', 'fk-bw-nums', [drawEl, genEl]);
+
+  const fill = el('div', 'fk-bar-f');
+  const bar = el('div', 'fk-bar', [fill]);
+
+  const brownout = el('div');
+  brownout.id = 'fk-brownout';
+  brownout.textContent = COPY.brownout;
+
+  const buffer = stat('BUFFER', 'fk-buf');
+  const shipped = stat(COPY.shipped);
+  const run = stat(COPY.tick);
+  run.v.id = 'fk-run';
+
+  const items = new Map<string, ItemDef>(data.items.map((i) => [i.id, i]));
+  const chips: ChipRow = createChipRow(items);
+
+  root.append(head, nums, bar, brownout, el('div', 'fk-rule'),
+    buffer.row, shipped.row, run.row, chips.el);
+
+  return {
+    el: root,
+    update(snap) {
+      const { gen, draw, stored, brownout: out } = snap.bandwidth;
+
+      text(drawEl, `${draw.toFixed(0)} DRAW`);
+      text(genEl, `${gen.toFixed(0)} GEN`);
+
+      // With no generators at all, any draw is already over budget.
+      const ratio = gen > 0 ? draw / gen : draw > 0 ? Infinity : 0;
+      style(fill, 'width', `${Math.min(1, ratio) * 100}%`);
+      cls(root, 'is-tight', !out && ratio >= TIGHT_AT);
+      cls(root, 'is-brownout', out || ratio > 1);
+
+      text(buffer.v, stored.toFixed(0));
+
+      let total = 0;
+      for (const n of Object.values(snap.shippedTotal)) total += n;
+      text(shipped.v, String(total));
+
+      text(run.v, snap.paused ? COPY.paused : `${snap.tick}`);
+      cls(run.v, 'is-paused', snap.paused);
+
+      chips.update(
+        Object.entries(snap.shippedTotal)
+          .filter(([, n]) => n > 0)
+          .map(([item, n]) => ({ item, count: String(n), state: 'met' as const })),
+      );
+    },
+  };
+}