diff --git a/app/models.py b/app/models.py
index 47bddcc..c66b69a 100644
--- a/app/models.py
+++ b/app/models.py
@@ -1,36 +1,37 @@
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from enum import StrEnum
 from uuid import UUID
 
-from pydantic import AnyHttpUrl, BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, field_validator
+from pydantic.networks import AnyHttpUrl
 
 
-def utc_now() -> datetime:
-    return datetime.now(timezone.utc)
-
-
-class HealthState(StrEnum):
+class State(StrEnum):
     unknown = "unknown"
     up = "up"
     down = "down"
+    error = "error"
 
 
-class MonitorCreate(BaseModel):
-    name: str = Field(min_length=1, max_length=120)
+class MonitorInput(BaseModel):
+    name: str = Field(min_length=1, max_length=100)
     url: AnyHttpUrl
+    timeout_seconds: float | None = Field(default=None, gt=0, le=30)
+
+    @field_validator("url")
+    @classmethod
+    def reject_credentials(cls, value: AnyHttpUrl) -> AnyHttpUrl:
+        if value.username or value.password:
+            raise ValueError("URL credentials are not allowed")
+        return value
 
 
-class MonitorUpdate(MonitorCreate):
-    pass
-
-
-class CurrentStatus(BaseModel):
-    state: HealthState
-    checked_at: datetime
-    latency_ms: float = Field(ge=0)
+class CheckSnapshot(BaseModel):
+    state: State = State.unknown
+    checked_at: datetime | None = None
+    latency_ms: float | None = None
     http_status: int | None = None
-    error_code: str | None = None
-    error_message: str | None = None
+    error: str | None = None
 
 
 class Monitor(BaseModel):
@@ -39,18 +40,16 @@ class Monitor(BaseModel):
     id: UUID
     name: str
     url: AnyHttpUrl
+    timeout_seconds: float | None
     created_at: datetime
     updated_at: datetime
     revision: int
-    current_status: CurrentStatus | None = None
+    status: CheckSnapshot
 
 
-class CheckResponse(BaseModel):
+class CheckResult(CheckSnapshot):
     monitor_id: UUID
-    status: CurrentStatus
-    applied: bool
 
 
-class ErrorDetail(BaseModel):
-    code: str
-    message: str
+def now() -> datetime:
+    return datetime.now(UTC)