diff --git a/src/endpoint_monitor/models.py b/src/endpoint_monitor/models.py
new file mode 100644
index 0000000..757c955
--- /dev/null
+++ b/src/endpoint_monitor/models.py
@@ -0,0 +1,54 @@
+from datetime import datetime
+from enum import Enum
+from uuid import UUID
+
+from pydantic import AnyHttpUrl, BaseModel, ConfigDict, Field
+
+
+class MonitorStatus(str, Enum):
+    UNKNOWN = "unknown"
+    UP = "up"
+    DOWN = "down"
+    ERROR = "error"
+
+
+class MonitorCreate(BaseModel):
+    name: str = Field(min_length=1, max_length=100, pattern=r".*\S.*")
+    url: AnyHttpUrl
+
+
+class MonitorUpdate(BaseModel):
+    name: str | None = Field(default=None, min_length=1, max_length=100, pattern=r".*\S.*")
+    url: AnyHttpUrl | None = None
+
+
+class CheckResult(BaseModel):
+    status: MonitorStatus
+    checked_at: datetime
+    latency_ms: float = Field(ge=0)
+    http_status: int | None = None
+    final_url: str | None = None
+    detail: str | None = Field(default=None, max_length=300)
+
+
+class Monitor(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: UUID
+    name: str
+    url: AnyHttpUrl
+    created_at: datetime
+    updated_at: datetime
+    revision: int
+    status: MonitorStatus = MonitorStatus.UNKNOWN
+    last_check: CheckResult | None = None
+
+
+class StatusView(BaseModel):
+    id: UUID
+    status: MonitorStatus
+    last_check: CheckResult | None
+
+
+class Health(BaseModel):
+    status: str