diff --git a/src/solstone_linux/cli.py b/src/solstone_linux/cli.py
index 181e4e3..5fe0997 100644
--- a/src/solstone_linux/cli.py
+++ b/src/solstone_linux/cli.py
@@ -92,15 +92,34 @@ def cmd_setup(args: argparse.Namespace) -> int:
     config.ensure_dirs()
     save_config(config)
 
-    # Auto-register
+    # Auto-register — try sol CLI first (no server needed), fall back to HTTP
     if not config.key:
-        print("Registering with server...")
-        client = UploadClient(config)
-        if client.ensure_registered(config):
-            config = load_config()
-            print(f"Registered (key: {config.key[:8]}...)")
-        else:
-            print("Warning: registration failed. Run setup again when server is available.")
+        sol = shutil.which("sol")
+        if sol:
+            print("Registering via sol CLI...")
+            try:
+                result = subprocess.run(
+                    [sol, "remote", "--json", "create", config.stream],
+                    capture_output=True, text=True, timeout=10,
+                )
+                if result.returncode == 0:
+                    data = json.loads(result.stdout)
+                    config.key = data["key"]
+                    save_config(config)
+                    print(f"Registered (key: {config.key[:8]}...)")
+                else:
+                    print(f"CLI registration failed, trying HTTP...")
+            except (subprocess.TimeoutExpired, json.JSONDecodeError, KeyError, OSError):
+                print("CLI registration failed, trying HTTP...")
+
+        if not config.key:
+            print("Registering with server...")
+            client = UploadClient(config)
+            if client.ensure_registered(config):
+                config = load_config()
+                print(f"Registered (key: {config.key[:8]}...)")
+            else:
+                print("Warning: registration failed. Run setup again when server is available.")
     else:
         print(f"Already registered (key: {config.key[:8]}...)")
 
diff --git a/src/solstone_linux/upload.py b/src/solstone_linux/upload.py
index 7a6844d..2c423a3 100644
--- a/src/solstone_linux/upload.py
+++ b/src/solstone_linux/upload.py
@@ -15,6 +15,8 @@ from __future__ import annotations
 
 import json
 import logging
+import shutil
+import subprocess
 import time
 from enum import Enum
 from pathlib import Path
@@ -70,15 +72,34 @@ class UploadClient:
     def ensure_registered(self, config: Config) -> bool:
         """Ensure the client has a valid key, auto-registering if needed.
 
+        Tries sol CLI first (no server needed), falls back to HTTP.
         Returns True if a key is available.
         """
         if self._key:
             return True
+
+        # Try sol CLI registration first
+        name = self._stream or "solstone-linux"
+        sol = shutil.which("sol")
+        if sol:
+            try:
+                result = subprocess.run(
+                    [sol, "remote", "--json", "create", name],
+                    capture_output=True, text=True, timeout=10,
+                )
+                if result.returncode == 0:
+                    data = json.loads(result.stdout)
+                    self._key = data["key"]
+                    self._persist_key(config, self._key)
+                    logger.info(f"CLI-registered as '{name}' (key: {self._key[:8]}...)")
+                    return True
+            except (subprocess.TimeoutExpired, json.JSONDecodeError, KeyError, OSError) as e:
+                logger.debug(f"CLI registration failed: {e}")
+
         if not self._url:
             return False
 
         url = f"{self._url}/app/remote/api/create"
-        name = self._stream or "solstone-linux"
 
         retries = min(3, len(self._retry_backoff))
         for attempt in range(retries):