diff --git a/pkgs/clan-cli/clan_cli/config/__init__.py b/pkgs/clan-cli/clan_cli/config/__init__.py
index d20b66731..5182f2639 100644
--- a/pkgs/clan-cli/clan_cli/config/__init__.py
+++ b/pkgs/clan-cli/clan_cli/config/__init__.py
@@ -28,10 +28,7 @@ def map_type(type: str) -> Any:
         "16 bit unsigned integer; between 0 and 65535 (both inclusive)",
     ]:
         return int
-    elif type == "string":
-        return str
-    # lib.type.passwdEntry
-    elif type == "string, not containing newlines or colons":
+    elif type.startswith("string"):
         return str
     elif type.startswith("null or "):
         subtype = type.removeprefix("null or ")
diff --git a/pkgs/clan-cli/clan_cli/config/machine.py b/pkgs/clan-cli/clan_cli/config/machine.py
index c309b36f9..ba4e7fb3c 100644
--- a/pkgs/clan-cli/clan_cli/config/machine.py
+++ b/pkgs/clan-cli/clan_cli/config/machine.py
@@ -12,6 +12,32 @@ from clan_cli.machines.folders import machine_folder, machine_settings_file
 from clan_cli.nix import nix_eval
 
 
+def verify_machine_config(
+    machine_name: str, flake: Optional[Path] = None
+) -> tuple[bool, Optional[str]]:
+    """
+    Verify that the machine evaluates successfully
+    Returns a tuple of (success, error_message)
+    """
+    if flake is None:
+        flake = get_clan_flake_toplevel()
+    proc = subprocess.run(
+        nix_eval(
+            flags=[
+                "--impure",
+                "--show-trace",
+                f".#nixosConfigurations.{machine_name}.config.system.build.toplevel.outPath",
+            ],
+        ),
+        capture_output=True,
+        text=True,
+        cwd=flake,
+    )
+    if proc.returncode != 0:
+        return False, proc.stderr
+    return True, None
+
+
 def config_for_machine(machine_name: str) -> dict:
     # read the config from a json file located at {flake}/machines/{machine_name}/settings.json
     if not machine_folder(machine_name).exists():
diff --git a/pkgs/clan-cli/clan_cli/webui/routers/machines.py b/pkgs/clan-cli/clan_cli/webui/routers/machines.py
index 1a19530a4..3eb815e77 100644
--- a/pkgs/clan-cli/clan_cli/webui/routers/machines.py
+++ b/pkgs/clan-cli/clan_cli/webui/routers/machines.py
@@ -4,6 +4,8 @@ from typing import Annotated
 
 from fastapi import APIRouter, Body
 
+import clan_cli.config as config
+
 from ...config.machine import (
     config_for_machine,
     schema_for_machine,
@@ -19,6 +21,7 @@ from ..schemas import (
     MachinesResponse,
     SchemaResponse,
     Status,
+    VerifyMachineResponse,
 )
 
 log = logging.getLogger(__name__)
@@ -63,3 +66,9 @@ async def set_machine_config(
 async def get_machine_schema(name: str) -> SchemaResponse:
     schema = schema_for_machine(name)
     return SchemaResponse(schema=schema)
+
+
+@router.get("/api/machines/{name}/verify")
+async def verify_machine_config(name: str) -> VerifyMachineResponse:
+    success, error = config.machine.verify_machine_config(name)
+    return VerifyMachineResponse(success=success, error=error)
diff --git a/pkgs/clan-cli/clan_cli/webui/schemas.py b/pkgs/clan-cli/clan_cli/webui/schemas.py
index c53636c5a..43ac47a10 100644
--- a/pkgs/clan-cli/clan_cli/webui/schemas.py
+++ b/pkgs/clan-cli/clan_cli/webui/schemas.py
@@ -38,6 +38,11 @@ class SchemaResponse(BaseModel):
     schema_: dict = Field(alias="schema")
 
 
+class VerifyMachineResponse(BaseModel):
+    success: bool
+    error: str | None
+
+
 class VmStatusResponse(BaseModel):
     error: str | None
     status: TaskStatus
diff --git a/pkgs/clan-cli/tests/test_machines_api.py b/pkgs/clan-cli/tests/test_machines_api.py
index 2fba07593..fd944ee9c 100644
--- a/pkgs/clan-cli/tests/test_machines_api.py
+++ b/pkgs/clan-cli/tests/test_machines_api.py
@@ -46,18 +46,40 @@ def test_configure_machine(api: TestClient, test_flake: Path) -> None:
     assert "schema" in json_response and "properties" in json_response["schema"]
 
     # set some config
-    response = api.put(
-        "/api/machines/machine1/config",
-        json=dict(
-            clan=dict(
-                jitsi=True,
-            )
+    config = dict(
+        clan=dict(
+            jitsi=dict(
+                enable=True,
+            ),
+        ),
+        fileSystems={
+            "/": dict(
+                device="/dev/fake_disk",
+                fsType="ext4",
+            ),
+        },
+        # set boot.loader.grub.devices
+        boot=dict(
+            loader=dict(
+                grub=dict(
+                    devices=["/dev/fake_disk"],
+                ),
+            ),
         ),
     )
+    response = api.put(
+        "/api/machines/machine1/config",
+        json=config,
+    )
     assert response.status_code == 200
-    assert response.json() == {"config": {"clan": {"jitsi": True}}}
+    assert response.json() == {"config": config}
+
+    # verify the machine config
+    response = api.get("/api/machines/machine1/verify")
+    assert response.status_code == 200
+    assert response.json() == {"success": True, "error": None}
 
     # get the config again
     response = api.get("/api/machines/machine1/config")
     assert response.status_code == 200
-    assert response.json() == {"config": {"clan": {"jitsi": True}}}
+    assert response.json() == {"config": config}