diff --git a/gitnexus-cursor-integration/hooks/gitnexus-hook.cjs b/gitnexus-cursor-integration/hooks/gitnexus-hook.cjs
index ffddd163e..66b17f84f 100644
--- a/gitnexus-cursor-integration/hooks/gitnexus-hook.cjs
+++ b/gitnexus-cursor-integration/hooks/gitnexus-hook.cjs
@@ -339,6 +339,67 @@ function resolveCliPath() {
   }
 }
 
+// The Cursor host enforces hooks.json's postToolUse `timeout` (seconds)
+// against the whole hook process. hooks.json ships 60s so a cold
+// `npx -y gitnexus` (package download + install) can actually finish; the
+// npx fallback budget is then sized from the remaining host budget minus
+// headroom for node startup and the final stdout write, instead of a flat
+// inner+5s that could overshoot or undercut the deadline.
+const CURSOR_NPX_HEADROOM_MS = 5000;
+const CURSOR_HOOK_START_MS = Date.now();
+const HOOK_ENV = process['env'];
+
+function resolveCursorHostBudgetMs() {
+  try {
+    // hooks.json ships next to this hook script
+    const manifest = JSON.parse(fs.readFileSync(path.join(__dirname, 'hooks.json'), 'utf-8'));
+    const seconds = manifest.hooks.postToolUse[0].timeout;
+    if (typeof seconds === 'number' && seconds > 0) {
+      return seconds * 1000;
+    }
+  } catch {
+    /* fall through to the shipped default */
+  }
+  return 60000;
+}
+
+// Resolve a coreutils/BSD `timeout` binary for the npx arm. The CLI behind
+// npx is a grandchild (npx -> gitnexus), so the wrap leads with `-s KILL`:
+// a plain SIGTERM would kill only the obedient npx parent and let the
+// grandchild keep holding the LadybugDB lock after this hook released its
+// slot. Mirrors the Claude adapter's wrapped npx arm; Windows stays
+// unwrapped (npx is a .cmd script there).
+function resolveUnixGuardTimeout() {
+  if (process.platform === 'win32') return null;
+  const override = HOOK_ENV.GITNEXUS_HOOK_TIMEOUT_PATH;
+  if (override === 'disabled') return null;
+  const candidates = [];
+  if (override && override.trim()) candidates.push(override.trim());
+  candidates.push(
+    '/usr/bin/timeout',
+    '/usr/local/bin/timeout',
+    '/opt/homebrew/bin/timeout',
+    '/usr/bin/gtimeout',
+  );
+  for (const candidate of candidates) {
+    try {
+      if (candidate.includes('/') && fs.existsSync(candidate)) return candidate;
+      const probe = spawnSync('which', [candidate], {
+        encoding: 'utf-8',
+        timeout: 3000,
+        stdio: ['pipe', 'pipe', 'pipe'],
+        windowsHide: true,
+      });
+      if (probe.status === 0 && String(probe.stdout).trim()) {
+        return String(probe.stdout).trim();
+      }
+    } catch {
+      /* keep probing */
+    }
+  }
+  return null;
+}
+
 function runGitNexusCli(cliPath, args, cwd, timeout) {
   const isWin = process.platform === 'win32';
   if (cliPath) {
@@ -350,9 +411,42 @@ function runGitNexusCli(cliPath, args, cwd, timeout) {
       windowsHide: true,
     });
   }
+  const elapsed = Date.now() - CURSOR_HOOK_START_MS;
+  const npxTimeout = Math.max(
+    1000,
+    Math.min(timeout + 5000, resolveCursorHostBudgetMs() - CURSOR_NPX_HEADROOM_MS - elapsed),
+  );
+  const guard = resolveUnixGuardTimeout();
+  if (guard) {
+    const wrapped = spawnSync(
+      guard,
+      [
+        '-s',
+        'KILL',
+        '-k',
+        '1',
+        String(Math.ceil(npxTimeout / 1000) + 1),
+        'npx',
+        '-y',
+        'gitnexus',
+        ...args,
+      ],
+      {
+        encoding: 'utf-8',
+        timeout: npxTimeout + 2000,
+        cwd,
+        stdio: ['pipe', 'pipe', 'pipe'],
+        windowsHide: true,
+      },
+    );
+    if (!wrapped.error || wrapped.error.code !== 'ENOENT') {
+      return wrapped;
+    }
+    // guard vanished between probe and spawn: fall through unwrapped
+  }
   return spawnSync(isWin ? 'npx.cmd' : 'npx', ['-y', 'gitnexus', ...args], {
     encoding: 'utf-8',
-    timeout: timeout + 5000,
+    timeout: npxTimeout,
     cwd,
     stdio: ['pipe', 'pipe', 'pipe'],
     windowsHide: true,
diff --git a/gitnexus-cursor-integration/hooks/hooks.json b/gitnexus-cursor-integration/hooks/hooks.json
index 9ae542c14..88e2142c0 100644
--- a/gitnexus-cursor-integration/hooks/hooks.json
+++ b/gitnexus-cursor-integration/hooks/hooks.json
@@ -5,7 +5,7 @@
       {
         "matcher": "Shell|Read|Grep",
         "command": "node ./hooks/gitnexus-hook.cjs",
-        "timeout": 10
+        "timeout": 60
       }
     ]
   }
diff --git a/gitnexus/test/unit/cursor-hook.test.ts b/gitnexus/test/unit/cursor-hook.test.ts
index 4fe58eafa..88b241a8a 100644
--- a/gitnexus/test/unit/cursor-hook.test.ts
+++ b/gitnexus/test/unit/cursor-hook.test.ts
@@ -441,6 +441,47 @@ describe('Cursor hook debug logging', () => {
   });
 });
 
+// ─── Source code regression: npx fallback stays under the host budget ─────
+
+describe('Cursor hook npx fallback host budget', () => {
+  const source = fs.readFileSync(CURSOR_HOOK, 'utf-8');
+  const manifest = JSON.parse(
+    fs.readFileSync(path.join(path.dirname(CURSOR_HOOK), 'hooks.json'), 'utf-8'),
+  );
+
+  it('ships a postToolUse timeout with room for a cold npx install', () => {
+    // Cold `npx -y gitnexus` has to download + install the package; the
+    // original 10s budget killed the hook before the child could ever
+    // finish. The existing manifest test only pins (0, 120).
+    const seconds = manifest.hooks.postToolUse[0].timeout;
+    expect(seconds).toBeGreaterThanOrEqual(30);
+    expect(seconds).toBeLessThan(120);
+  });
+
+  it('sizes the npx timeout from the host budget with headroom', () => {
+    // Extract runGitNexusCli so the assertions are tied to the actual
+    // spawn wiring, not just to unrelated substrings elsewhere.
+    const fnStart = source.indexOf('function runGitNexusCli');
+    const fnBody = source.slice(fnStart, source.indexOf('\n}\n', fnStart));
+
+    // budget comes from hooks.json (seconds → ms), with headroom applied
+    expect(fnBody).toContain('resolveCursorHostBudgetMs() - CURSOR_NPX_HEADROOM_MS - elapsed');
+    // the computed budget is what reaches spawnSync (not a bare +5000)
+    expect(fnBody).toContain('timeout: npxTimeout');
+    expect(fnBody).not.toMatch(/timeout:\s*timeout\s*\+\s*5000/);
+    // npx grandchild is killed outright so it cannot keep the DB lock
+    expect(fnBody).toMatch(/['"]-s['"]/);
+    expect(fnBody).toMatch(/['"]KILL['"]/);
+  });
+
+  it('reads the shipped timeout value, not a detached literal', () => {
+    // resolveCursorHostBudgetMs must parse hooks.json so changing the
+    // manifest cannot silently desync from the hook budget.
+    expect(source).toContain('postToolUse[0].timeout');
+    expect(source).toContain('return seconds * 1000;');
+  });
+});
+
 // ─── Source code regression: concurrency guard (#1486) ─────────────
 
 describe('Cursor hook concurrency guard', () => {