diff --git a/agents/AGENTS.global.md b/agent/AGENTS.md
similarity index 100%
rename from agents/AGENTS.global.md
rename to agent/AGENTS.md
diff --git a/agent/extensions/notify-focus.sh b/agent/extensions/notify-focus.sh
new file mode 100755
index 0000000..bce917c
--- /dev/null
+++ b/agent/extensions/notify-focus.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+# notify-focus.sh — invoked by terminal-notifier when the Pi notification is
+# clicked. Focuses Ghostty and switches the most-recently-active tmux client
+# to the session/window/pane the agent was running in.
+#
+# Usage: notify-focus.sh <session> <window> <pane>
+#
+# terminal-notifier runs -execute scripts with a minimal PATH (/usr/bin:/bin),
+# so homebrew's tmux isn't found unless we resolve it to an absolute path.
+set -u
+
+TMUX_BIN=""
+for _p in /opt/homebrew/bin/tmux /usr/local/bin/tmux; do
+  [ -x "$_p" ] && TMUX_BIN="$_p" && break
+done
+: "${TMUX_BIN:=$(command -v tmux 2>/dev/null || true)}"
+
+SESSION="${1:-}"
+WINDOW="${2:-}"
+PANE="${3:-}"
+
+[ -n "$SESSION" ] && [ -n "$TMUX_BIN" ] || exit 0
+
+open -a Ghostty 2>/dev/null || true
+
+# Switch the most-recently-active client (highest #{client_activity}) to the
+# target session, then land on the window/pane. A pane id is globally unique
+# and selecting it also switches to its containing window, so prefer it over
+# a bare window target.
+C=$("$TMUX_BIN" list-clients -F '#{client_activity} #{client_name}' 2>/dev/null \
+  | sort -rn | head -1 | cut -d' ' -f2-)
+"$TMUX_BIN" switch-client -c "$C" -t "$SESSION" 2>/dev/null || true
+
+if [ -n "$PANE" ]; then
+  "$TMUX_BIN" select-pane -t "$PANE" 2>/dev/null || true
+elif [ -n "$WINDOW" ]; then
+  "$TMUX_BIN" select-window -t "$SESSION":"$WINDOW" 2>/dev/null || true
+fi
\ No newline at end of file
diff --git a/agent/extensions/notify.ts b/agent/extensions/notify.ts
new file mode 100644
index 0000000..5ae9043
--- /dev/null
+++ b/agent/extensions/notify.ts
@@ -0,0 +1,244 @@
+/**
+ * notify.ts — Desktop notifications for Pi (macOS / Ghostty).
+ *
+ * Posts a native macOS notification via `terminal-notifier` when the agent
+ * finishes a turn and is waiting for input. Works regardless of tmux
+ * session/window — terminal-notifier runs outside the terminal stream, so
+ * tmux's same-session passthrough scoping (tmux PR #3501) is irrelevant.
+ *
+ * Clicking the notification focuses Ghostty and switches the active tmux
+ * client to the session/window/pane the agent ran in (see notify-focus.sh).
+ * NOTE: terminal-notifier's click actions (-activate/-execute) are reported
+ * broken on macOS Ventura+ due to security changes — clicking may do nothing,
+ * in which case the notification still serves as a passive banner + sound.
+ * For guaranteed click-to-action, a signed app bundle with UNNotificationAction
+ * would be required.
+ *
+ * Requires `terminal-notifier` (brew install terminal-notifier) and a tmux
+ * session (relies on $TMUX_PANE). No fallback path.
+ *
+ * Suppression: the notification is skipped when you are already viewing the
+ * agent's surface — i.e. Ghostty is the frontmost app and the most-recently-
+ * active tmux client is attached to the agent's session on the agent's
+ * window. Any doubt (other app frontmost, different session, detached, etc.)
+ * errs toward notifying.
+ *
+ * Place at ~/.pi/agent/extensions/notify.ts (auto-discovered globally).
+ * Reload with /reload, or test with `pi -e ~/.pi/agent/extensions/notify.ts`.
+ */
+
+import { execFileSync, spawn } from "node:child_process";
+import { existsSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+
+const EXT_DIR = dirname(fileURLToPath(import.meta.url));
+const FOCUS_SCRIPT = join(EXT_DIR, "notify-focus.sh");
+
+function findTerminalNotifier(): string | null {
+  const candidates = [
+    "/opt/homebrew/bin/terminal-notifier",
+    "/usr/local/bin/terminal-notifier",
+  ];
+  for (const p of candidates) {
+    if (existsSync(p)) return p;
+  }
+  try {
+    const out = execFileSync("which", ["terminal-notifier"], {
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "ignore"],
+    }).trim();
+    return out || null;
+  } catch {
+    return null;
+  }
+}
+
+const TERMINAL_NOTIFIER = findTerminalNotifier();
+
+interface TmuxTarget {
+  session: string;
+  window: string;
+  pane: string;
+}
+
+function currentTmuxTarget(): TmuxTarget | null {
+  const paneId = process.env.TMUX_PANE;
+  if (!paneId) return null;
+  try {
+    // Format fields tab-separated; #{pane_id} is unique across the server.
+    const out = execFileSync(
+      "tmux",
+      ["display-message", "-p", "-t", paneId, "-F", "#{session_name}\t#{window_index}\t#{pane_id}"],
+      { encoding: "utf8", stdio: ["ignore", "pipe", "ignore"] },
+    ).trim();
+    const [session, window, pane] = out.split("\t");
+    if (!session) return null;
+    return { session, window: window ?? "", pane: pane ?? "" };
+  } catch {
+    return null;
+  }
+}
+
+// ── Suppression: is the user already viewing the agent's surface? ──────
+
+function frontmostIsGhostty(): boolean {
+  try {
+    const name = execFileSync(
+      "osascript",
+      ["-e", 'tell application "System Events" to get name of first application process whose frontmost is true'],
+      { encoding: "utf8", stdio: ["ignore", "pipe", "ignore"] },
+    ).trim().toLowerCase();
+    return name.includes("ghostty");
+  } catch {
+    return false; // System Events blocked or unavailable — assume not viewing
+  }
+}
+
+function userIsViewingAgent(target: TmuxTarget): boolean {
+  // Step 1: Ghostty must be the frontmost app. If the user is in another app,
+  // they are not viewing the agent — notify.
+  if (!frontmostIsGhostty()) return false;
+
+  // Step 2: Find the most-recently-active attached tmux client (that's where
+  // the user effectively is). #{client_activity} is an epoch-second count.
+  let mrcSession: string | null = null;
+  try {
+    const out = execFileSync(
+      "tmux",
+      ["list-clients", "-F", "#{client_activity}\t#{client_session}"],
+      { encoding: "utf8", stdio: ["ignore", "pipe", "ignore"] },
+    ).trim();
+    if (!out) return false; // no attached clients → user not viewing → notify
+    let best = -1;
+    for (const line of out.split("\n")) {
+      const [actStr, sess] = line.split("\t");
+      const act = Number(actStr);
+      if (Number.isFinite(act) && act > best && sess) {
+        best = act;
+        mrcSession = sess;
+      }
+    }
+  } catch {
+    return false; // tmux query failed — assume not viewing → notify
+  }
+
+  if (!mrcSession || mrcSession !== target.session) return false; // different session → notify
+
+  // Step 3: The user is in the agent's session. Are they on the agent's
+  // window? Per-client window fields are blank in tmux 3.6b, so the session's
+  // active window is the reliable signal for what the attached client shows.
+  try {
+    const activeWindow = execFileSync(
+      "tmux",
+      ["display-message", "-p", "-t", target.session, "-F", "#{window_index}"],
+      { encoding: "utf8", stdio: ["ignore", "pipe", "ignore"] },
+    ).trim();
+    return activeWindow === target.window;
+  } catch {
+    return false; // failed → assume not viewing → notify
+  }
+}
+
+function sendNotification(title: string, body: string): void {
+  if (process.platform !== "darwin") return;
+  if (!TERMINAL_NOTIFIER) return; // requires terminal-notifier, no fallback
+
+  const target = currentTmuxTarget();
+  if (!target) return; // requires a tmux pane, no fallback
+
+  if (userIsViewingAgent(target)) return; // already viewing the agent → skip
+
+  const args = [
+    "-title", title,
+    "-message", body,
+    "-sound", "default",
+    "-activate", "com.mitchellh.ghostty",
+    "-execute", `${FOCUS_SCRIPT} ${target.session} ${target.window} ${target.pane}`,
+    "-group", "pi-notify",
+  ];
+  const proc = spawn(TERMINAL_NOTIFIER, args, { stdio: "ignore" });
+  proc.unref();
+  proc.on("error", () => {
+    /* terminal-notifier vanished at runtime — nothing else to try */
+  });
+}
+
+// ── Run tracking ───────────────────────────────────────────────────────
+// Summarizes what happened during the agent run so the notification body
+// is informative (e.g. "✅ Done — 2 turns, 5 tool calls (3 unique)").
+
+interface RunStats {
+  turns: number;
+  toolCalls: number;
+  errors: number;
+  toolNames: Set<string>;
+}
+
+function freshStats(): RunStats {
+  return { turns: 0, toolCalls: 0, errors: 0, toolNames: new Set() };
+}
+
+function formatAgentEndMessage(stats: RunStats): string {
+  const emoji = stats.errors > 0 ? "❌" : "✅";
+  const parts: string[] = [];
+
+  if (stats.turns === 1) {
+    parts.push("1 turn");
+  } else if (stats.turns > 1) {
+    parts.push(`${String(stats.turns)} turns`);
+  }
+
+  if (stats.toolCalls > 0) {
+    const uniqueCount = stats.toolNames.size;
+    parts.push(
+      `${String(stats.toolCalls)} tool ${stats.toolCalls === 1 ? "call" : "calls"} (${String(uniqueCount)} unique)`,
+    );
+  }
+
+  if (stats.errors > 0) {
+    parts.push(`${String(stats.errors)} ${stats.errors === 1 ? "error" : "errors"}`);
+  }
+
+  const summary = parts.length > 0 ? parts.join(", ") : "no tool calls";
+  return `${emoji} Done — ${summary}`;
+}
+
+// ── Extension factory ──────────────────────────────────────────────────
+
+export default function (pi: ExtensionAPI): void {
+  const TITLE = "Pi";
+  let stats = freshStats();
+
+  // Reset per prompt.
+  pi.on("agent_start", () => {
+    stats = freshStats();
+  });
+
+  pi.on("turn_end", () => {
+    stats.turns++;
+  });
+
+  pi.on("tool_execution_end", (event) => {
+    stats.toolCalls++;
+    stats.toolNames.add(event.toolName);
+    if (event.isError) {
+      stats.errors++;
+    }
+  });
+
+  // Agent finished its turn and is waiting for input: notify.
+  pi.on("agent_end", () => {
+    sendNotification(TITLE, formatAgentEndMessage(stats));
+  });
+
+  pi.registerCommand("notify", {
+    description: "Send a test macOS desktop notification.",
+    handler: (args) => {
+      const message = args.trim() || "Waiting for your input";
+      sendNotification(TITLE, `🔔 ${message}`);
+      return Promise.resolve();
+    },
+  });
+}
\ No newline at end of file
diff --git a/setup.sh b/setup.sh
index e0d088b..6a45e90 100755
--- a/setup.sh
+++ b/setup.sh
@@ -22,7 +22,9 @@ function link_configs {
   mappings["zsh/starship.toml"]="$HOME/.config/starship.toml"
   mappings["mise"]="$HOME/.config/mise"
   mappings["worktrunk/config.toml"]="$HOME/.config/worktrunk/config.toml"
-  mappings["agents/AGENTS.global.md"]="$HOME/.claude/CLAUDE.md"
+  mappings["agent/AGENTS.md"]="$HOME/.pi/agent/AGENTS.md"
+  mappings["agent/extensions/notify.ts"]="$HOME/.pi/agent/extensions/notify.ts"
+  mappings["agent/extensions/notify-focus.sh"]="$HOME/.pi/agent/extensions/notify-focus.sh"
 
   for key in "${!mappings[@]}"; do
     source="${key}"