diff --git a/src/session/session.ts b/src/session/session.ts
index 416b508..228ed71 100644
--- a/src/session/session.ts
+++ b/src/session/session.ts
@@ -81,10 +81,23 @@ export function createSession(
   // event belongs to ($WEBTERM_SESSION) and where to POST ($WEBTERM_HOOK_URL, H2).
   const tName = cfg.useTmux ? tmuxName(id) : null;
 
+  // Spawn the shell as a LOGIN shell (POSIX only) so it loads the full profile
+  // chain (/etc/zprofile, ~/.zprofile, ~/.zshrc, …) and rebuilds PATH — exactly
+  // like Terminal.app / iTerm. Without `-l`, a shell spawned by a GUI-launched
+  // app (Finder / login-item) or a long-lived tmux keepalive server inherits a
+  // minimal PATH, so nvm-managed `node` (only on the login PATH) is missing and
+  // Claude Code hooks fail with "node: command not found". PowerShell (Windows)
+  // has no `-l`; skip it there (Windows also forces tmux off — server-config.ts).
+  const loginArgs = process.platform === 'win32' ? [] : ['-l'];
+
   // H1: under tmux, the node-pty process is a tmux CLIENT; `new-session -A`
-  // attaches to web_<id> if it exists (restart survival) or creates it.
+  // attaches to web_<id> if it exists (restart survival) or creates it. The
+  // shell-command (shellPath + login flag) is the tmux session's root process.
   const file = tName !== null ? 'tmux' : cfg.shellPath;
-  const args = tName !== null ? ['new-session', '-A', '-s', tName, cfg.shellPath] : [];
+  const args =
+    tName !== null
+      ? ['new-session', '-A', '-s', tName, cfg.shellPath, ...loginArgs]
+      : loginArgs;
 
   // M4: let a spawn failure (e.g. missing shell / tmux) propagate synchronously.
   const pty: IPty = spawn(file, args, {