diff --git a/bin/cli.js b/bin/cli.js
index fdfdf49..99c8971 100755
--- a/bin/cli.js
+++ b/bin/cli.js
@@ -45,6 +45,20 @@ const { exportArchive, importArchive } = require('../src/migrate');
 const { convertSession } = require('../src/convert');
 const { generateHandoff, quickHandoff } = require('../src/handoff');
 const { cloudCLI } = require('../src/cloud');
+const { augmentPathFromLoginShell } = require('../src/shell-path');
+
+// GUI launches (Finder/Dock/Spotlight) inherit a stripped PATH that omits user
+// bin dirs where `claude`/`codex` live, which breaks PATH-based agent detection.
+// Repair it from the login shell before any command runs. No-op (no shell
+// spawn) when launched from a terminal that already has the full PATH.
+try {
+  const added = augmentPathFromLoginShell();
+  if (added.length) {
+    console.error(`[codbash] PATH augmented from login shell (+${added.length} dir${added.length === 1 ? '' : 's'})`);
+  }
+} catch (err) {
+  console.error('[codbash] PATH augmentation skipped:', err && err.message ? err.message : err);
+}
 
 const DEFAULT_PORT = 3847;
 const DEFAULT_HOST = 'localhost';
diff --git a/src/shell-path.js b/src/shell-path.js
new file mode 100644
index 0000000..1875704
--- /dev/null
+++ b/src/shell-path.js
@@ -0,0 +1,166 @@
+// Repair PATH for GUI launches on macOS/Linux.
+//
+// When codbash.app is launched from Finder/Dock/Spotlight, macOS gives the
+// process a minimal PATH (typically `/usr/bin:/bin:/usr/sbin:/sbin`) that does
+// NOT include user bin directories such as `~/.local/bin`, `~/.npm-global/bin`,
+// nvm/fnm shims, or Homebrew. CLIs like `claude` and `codex` are usually
+// installed there, so PATH-based agent detection (see agents-detect.js) misses
+// them — even though they are installed and their history is present. Agents
+// that ship as a `.app` bundle (Cursor) still detect, which is why a GUI launch
+// often shows only Cursor while the terminal-launched CLI shows everything.
+//
+// We repair `process.env.PATH` once at startup by asking the user's login shell
+// for its PATH — mirroring exactly what a terminal-launched process would see.
+// When already launched from a terminal (PATH already contains user bin dirs)
+// this is a cheap no-op: we never spawn a shell.
+//
+// Opt out entirely with `CODBASH_NO_PATH_REPAIR=1`. Set `CODBASH_DEBUG=1` to
+// log the skip/augment decisions to stderr.
+
+const { execFileSync } = require('child_process');
+const os = require('os');
+const path = require('path');
+
+let _done = false;
+
+function debugEnabled() {
+  return process.env.CODBASH_DEBUG === '1' || process.env.CODBASH_DEBUG === 'true';
+}
+function debug(msg) {
+  if (debugEnabled()) {
+    try { console.error('[codbash] ' + msg); } catch (_) { /* stderr closed */ }
+  }
+}
+
+// Reject any PATH entry containing a C0/C1 control character, TAB, or DEL. A
+// blocklist (rather than a printable-ASCII allowlist) is used deliberately so
+// legitimate non-ASCII directory names — e.g. a Unicode home directory — are
+// preserved instead of being silently dropped.
+const CONTROL_CHARS = /[\x00-\x1f\x7f]/;
+
+// Does PATH already look like a real terminal session? We treat it as "good"
+// only when it contains a bin/shims directory *under the user's home* — the
+// kind of entry (`~/.local/bin`, `~/.npm-global/bin`, nvm/fnm shims) that agent
+// detection depends on. A lone unrelated home path (e.g. a LaunchServices
+// `~/Library/...` entry that some GUI launchers prepend) must NOT suppress the
+// repair, so a bare `startsWith($HOME)` test is deliberately avoided — it would
+// false-negative and leave detection broken with no shell probe ever running.
+function hasUserBinPaths(p, home) {
+  const h = home || os.homedir();
+  const prefix = h + path.sep;
+  return (p || '').split(path.delimiter).some(d => {
+    if (!d || !d.startsWith(prefix)) return false;
+    return d.endsWith(path.sep + 'bin')
+      || d.endsWith(path.sep + 'sbin')
+      || d.includes(path.sep + 'shims' + path.sep) || d.endsWith(path.sep + 'shims')
+      || d.includes(path.sep + '.nvm' + path.sep)
+      || d.includes(path.sep + '.fnm' + path.sep);
+  });
+}
+
+function captureLoginShellPath() {
+  let shell = process.env.SHELL || '';
+  // $SHELL is attacker-controllable only by someone who already has env-setting
+  // (= code-execution) capability in this process, so this is a robustness
+  // guard, not a trust boundary: reject an empty/relative value and fall back
+  // to the macOS default login shell (zsh since Catalina; this feature is
+  // macOS-focused — cf. terminal.js which defaults to bash for its own path).
+  if (!shell || !path.isAbsolute(shell)) shell = '/bin/zsh';
+
+  // Sentinels (SOH-delimited) let us pull PATH out of stdout even when rc files
+  // print banners / shell-integration escape sequences on startup. NOTE: this
+  // guards against *accidental* banner noise only — it is NOT a trust boundary
+  // against a malicious rc file, which already controls $PATH directly.
+  const script = 'printf "\\1CBP\\1%s\\1CBE\\1" "$PATH"';
+
+  // Separate flags (not a bundled `-ilc`) for portability across shells with
+  // stricter getopt parsing. `-i -l` sources both login (.zprofile/.zlogin) and
+  // interactive (.zshrc/.bashrc) config, so PATH matches a real terminal no
+  // matter which file the user's exports live in. Cost: this runs the user's rc
+  // chain once per app launch — an accepted tradeoff for correct detection.
+  // killSignal is SIGKILL because a shell/rc that traps or ignores SIGTERM
+  // could otherwise outlive the timeout; SIGKILL is still best-effort (a
+  // process blocked in an uninterruptible syscall cannot be reaped until it
+  // unblocks), so the 4s bound is a strong guideline, not a hard guarantee.
+  let raw;
+  try {
+    raw = execFileSync(shell, ['-i', '-l', '-c', script], {
+      encoding: 'utf8',
+      timeout: 4000,
+      killSignal: 'SIGKILL',
+      stdio: ['ignore', 'pipe', 'ignore'],
+    });
+  } catch (err) {
+    // Surface the failure (rare: bad $SHELL, hung rc file, sentinel timeout) so
+    // a field report of "detection still broken" is diagnosable, matching the
+    // repo-refresh startup logging convention in bin/cli.js.
+    console.error('[codbash] PATH repair: login-shell probe failed: ' + (err && err.message ? err.message : String(err)));
+    return '';
+  }
+  const m = /\x01CBP\x01([\s\S]*?)\x01CBE\x01/.exec(raw);
+  return m ? m[1] : '';
+}
+
+// Merge the login-shell PATH into process.env.PATH. Existing entries keep
+// priority; only previously-absent, control-char-free directories are appended.
+// Idempotent (guarded by `_done`; pass `{ force: true }` to re-run). Safe to
+// call unconditionally at startup. Returns the list of directories that were
+// added (empty when skipped or nothing new).
+function augmentPathFromLoginShell(opts) {
+  const o = opts || {};
+  if (_done && !o.force) return [];
+  _done = true;
+
+  // Explicit user opt-out — skips the login-shell spawn entirely.
+  if (process.env.CODBASH_NO_PATH_REPAIR === '1') {
+    debug('PATH repair disabled via CODBASH_NO_PATH_REPAIR');
+    return [];
+  }
+
+  const platform = o.platform || process.platform;
+  if (platform === 'win32') return []; // Windows GUI PATH is not stripped this way
+
+  const home = o.home || os.homedir();
+  const currentPath = o.path != null ? o.path : (process.env.PATH || '');
+
+  // Already a terminal-style PATH → nothing to repair, and no shell spawn.
+  if (hasUserBinPaths(currentPath, home)) {
+    debug('PATH already contains user bin dirs — skipping login-shell probe');
+    return [];
+  }
+
+  let captured = '';
+  try {
+    captured = o.capture ? o.capture() : captureLoginShellPath();
+  } catch (_) {
+    return []; // fail-safe: keep the existing PATH if the probe throws
+  }
+
+  // Trim BOTH sides so a stray-whitespace entry already present in PATH is not
+  // re-added as a spurious "new" duplicate.
+  const have = new Set(currentPath.split(path.delimiter).map(d => d.trim()).filter(Boolean));
+  const added = captured
+    .split(path.delimiter)
+    .map(d => d.trim())
+    .filter(d => d && !have.has(d) && !CONTROL_CHARS.test(d));
+
+  // Precedence is intentional: existing (system) entries stay FIRST and the
+  // login-shell dirs are appended AFTER — the opposite of a normal terminal
+  // (where user dirs usually win). Chosen so a directory discovered from the
+  // login shell can never shadow a base system binary; detection only needs the
+  // dir to be *present* on PATH, not first. (Duplicate casings on a
+  // case-insensitive filesystem are not normalized — accepted: unlikely and
+  // harmless, at worst a redundant PATH entry.)
+  if (added.length) {
+    const next = [...have, ...added].join(path.delimiter);
+    if (o.path == null) process.env.PATH = next;
+    debug('PATH augmented with: ' + added.join(', '));
+  }
+  return added;
+}
+
+module.exports = {
+  augmentPathFromLoginShell,
+  hasUserBinPaths,
+  captureLoginShellPath,
+};
diff --git a/test/shell-path.test.js b/test/shell-path.test.js
new file mode 100644
index 0000000..3755777
--- /dev/null
+++ b/test/shell-path.test.js
@@ -0,0 +1,158 @@
+// Tests for src/shell-path.js — login-shell PATH repair for GUI launches.
+//
+// Strategy: augmentPathFromLoginShell() takes an injected context
+// ({ platform, home, path, capture, force }) so we can drive every branch
+// without spawning a real shell or touching process.env — mirroring the DI
+// approach used in agents-detect.test.js.
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+function loadFresh() {
+  delete require.cache[require.resolve('../src/shell-path')];
+  return require('../src/shell-path');
+}
+
+const HOME = '/Users/test';
+const STRIPPED = '/usr/bin:/bin:/usr/sbin:/sbin';
+const LOGIN = '/Users/test/.local/bin:/Users/test/.npm-global/bin:/opt/homebrew/bin:/usr/bin:/bin';
+
+// Base options for a GUI-stripped darwin launch. Individual tests override.
+function base(over) {
+  return Object.assign({ force: true, platform: 'darwin', home: HOME, path: STRIPPED }, over);
+}
+
+test('hasUserBinPaths: false for a stripped GUI PATH', () => {
+  const { hasUserBinPaths } = loadFresh();
+  assert.equal(hasUserBinPaths(STRIPPED, HOME), false);
+});
+
+test('hasUserBinPaths: true when a bin dir under $HOME is present', () => {
+  const { hasUserBinPaths } = loadFresh();
+  assert.equal(hasUserBinPaths(LOGIN, HOME), true);
+});
+
+test('hasUserBinPaths: a lone non-bin home dir does NOT count (avoids false-negative skip)', () => {
+  const { hasUserBinPaths } = loadFresh();
+  const p = '/Users/test/Library/Caches/foo:/usr/bin:/bin';
+  assert.equal(hasUserBinPaths(p, HOME), false);
+});
+
+test('hasUserBinPaths: nvm/fnm shim dirs count', () => {
+  const { hasUserBinPaths } = loadFresh();
+  assert.equal(hasUserBinPaths('/Users/test/.nvm/versions/node/v20/bin:/usr/bin', HOME), true);
+  assert.equal(hasUserBinPaths('/Users/test/.fnm/aliases/default/bin:/usr/bin', HOME), true);
+});
+
+test('augment: stripped PATH gets login dirs appended, existing entries kept first', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const added = augmentPathFromLoginShell(base({ capture: () => LOGIN }));
+  assert.deepEqual(added, [
+    '/Users/test/.local/bin',
+    '/Users/test/.npm-global/bin',
+    '/opt/homebrew/bin',
+  ]);
+});
+
+test('augment: precedence — system dirs stay first, new dirs appended after (not prepended)', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  let written = null;
+  // Use the process.env path branch by omitting `path`, but capture the result
+  // via the return value + reconstruct expected ordering explicitly instead.
+  const added = augmentPathFromLoginShell(base({ capture: () => LOGIN }));
+  // The merged order is: existing (trimmed) entries, then added.
+  const expectedMerged = STRIPPED.split(':').concat(added).join(':');
+  assert.equal(
+    expectedMerged,
+    '/usr/bin:/bin:/usr/sbin:/sbin:/Users/test/.local/bin:/Users/test/.npm-global/bin:/opt/homebrew/bin'
+  );
+});
+
+test('augment: no-op (capture never called) when PATH already has user bin dirs', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  let called = false;
+  const added = augmentPathFromLoginShell(base({
+    path: LOGIN,
+    capture: () => { called = true; return LOGIN; },
+  }));
+  assert.deepEqual(added, []);
+  assert.equal(called, false, 'capture must not be invoked when PATH is already good');
+});
+
+test('augment: control-char entries (incl. TAB and DEL) are filtered out', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const added = augmentPathFromLoginShell(base({
+    capture: () => '/Users/test/.local/bin:/ta\tb/dir:/del\x7fdir:/ctrl\x01dir',
+  }));
+  assert.deepEqual(added, ['/Users/test/.local/bin']);
+});
+
+test('augment: does not re-add a dir already present, even with surrounding whitespace', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const added = augmentPathFromLoginShell(base({
+    path: ' /usr/bin : /bin ',
+    capture: () => '/usr/bin:/Users/test/.local/bin',
+  }));
+  assert.deepEqual(added, ['/Users/test/.local/bin'], 'trimmed existing entry should dedupe');
+});
+
+test('augment: win32 short-circuits without calling capture', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  let called = false;
+  const added = augmentPathFromLoginShell(base({
+    platform: 'win32',
+    capture: () => { called = true; return LOGIN; },
+  }));
+  assert.deepEqual(added, []);
+  assert.equal(called, false);
+});
+
+test('augment: CODBASH_NO_PATH_REPAIR=1 opts out without calling capture', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const prev = process.env.CODBASH_NO_PATH_REPAIR;
+  process.env.CODBASH_NO_PATH_REPAIR = '1';
+  try {
+    let called = false;
+    const added = augmentPathFromLoginShell(base({ capture: () => { called = true; return LOGIN; } }));
+    assert.deepEqual(added, []);
+    assert.equal(called, false);
+  } finally {
+    if (prev === undefined) delete process.env.CODBASH_NO_PATH_REPAIR;
+    else process.env.CODBASH_NO_PATH_REPAIR = prev;
+  }
+});
+
+test('augment: a throwing capture is swallowed and returns []', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const added = augmentPathFromLoginShell(base({
+    capture: () => { throw new Error('boom'); },
+  }));
+  assert.deepEqual(added, []);
+});
+
+test('augment: empty capture (no sentinel match) returns []', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const added = augmentPathFromLoginShell(base({ capture: () => '' }));
+  assert.deepEqual(added, []);
+});
+
+test('augment: idempotent — second call without force is a no-op even after state change', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const first = augmentPathFromLoginShell({ platform: 'darwin', home: HOME, path: STRIPPED, capture: () => LOGIN });
+  assert.ok(first.length > 0, 'first call augments');
+  const second = augmentPathFromLoginShell({ platform: 'darwin', home: HOME, path: STRIPPED, capture: () => LOGIN });
+  assert.deepEqual(second, [], 'second call without force is guarded by _done');
+});
+
+test('augment: mutates process.env.PATH when no explicit path is injected', () => {
+  const { augmentPathFromLoginShell } = loadFresh();
+  const prev = process.env.PATH;
+  process.env.PATH = STRIPPED;
+  try {
+    const added = augmentPathFromLoginShell({ force: true, platform: 'darwin', home: HOME, capture: () => LOGIN });
+    assert.ok(added.includes('/Users/test/.local/bin'));
+    assert.ok(process.env.PATH.includes('/Users/test/.local/bin'));
+    assert.ok(process.env.PATH.startsWith('/usr/bin:/bin'), 'system dirs remain first');
+  } finally {
+    process.env.PATH = prev;
+  }
+});