diff --git a/tests/test_server.py b/tests/test_server.py
new file mode 100644
index 0000000..aa77777
--- /dev/null
+++ b/tests/test_server.py
@@ -0,0 +1,148 @@
+import pytest
+from httpx import AsyncClient, ASGITransport
+from src.core.server import MockServer
+from src.models.config import ServerConfig
+from src.models.endpoint import Endpoint
+
+
+class TestMockServer:
+    @pytest.fixture
+    def config(self):
+        return ServerConfig(port=8888, host="127.0.0.1", offline=True)
+
+    @pytest.fixture
+    def server(self, config):
+        return MockServer(config)
+
+    @pytest.fixture
+    def sample_endpoints(self):
+        return [
+            Endpoint(
+                path="/api/hello",
+                method="GET",
+                response={"status_code": 200, "body": {"message": "Hello"}}
+            ),
+            Endpoint(
+                path="/api/users/{id}",
+                method="GET",
+                response={
+                    "status_code": 200,
+                    "body": {
+                        "id": "{{request.path.id}}",
+                        "name": "User {{request.path.id}}"
+                    }
+                }
+            ),
+            Endpoint(
+                path="/api/data",
+                method="POST",
+                response={"status_code": 201, "body": {"received": "{{request.body.key}}"}}
+            )
+        ]
+
+    def test_register_endpoint(self, server):
+        endpoint = Endpoint(
+            path="/api/test",
+            method="GET",
+            response={"status_code": 200}
+        )
+        server.register_endpoint(endpoint)
+        endpoints = server.matcher.get_endpoints()
+        assert len(endpoints) == 1
+
+    def test_register_endpoints(self, server, sample_endpoints):
+        server.register_endpoints(sample_endpoints)
+        endpoints = server.matcher.get_endpoints()
+        assert len(endpoints) == 3
+
+    @pytest.mark.asyncio
+    async def test_handle_simple_get(self, server, sample_endpoints):
+        server.register_endpoints(sample_endpoints)
+        app = server._create_app()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://test") as client:
+            response = await client.get("/api/hello")
+            assert response.status_code == 200
+            data = response.json()
+            assert data["message"] == "Hello"
+
+    @pytest.mark.asyncio
+    async def test_handle_path_params(self, server, sample_endpoints):
+        server.register_endpoints(sample_endpoints)
+        app = server._create_app()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://test") as client:
+            response = await client.get("/api/users/456")
+            assert response.status_code == 200
+            data = response.json()
+            assert data["id"] == "456"
+            assert data["name"] == "User 456"
+
+    @pytest.mark.asyncio
+    async def test_handle_post_with_body(self, server, sample_endpoints):
+        server.register_endpoints(sample_endpoints)
+        app = server._create_app()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://test") as client:
+            response = await client.post("/api/data", json={"key": "test_value"})
+            assert response.status_code == 201
+            data = response.json()
+            assert data["received"] == "test_value"
+
+    @pytest.mark.asyncio
+    async def test_handle_not_found(self, server, sample_endpoints):
+        server.register_endpoints(sample_endpoints)
+        app = server._create_app()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://test") as client:
+            response = await client.get("/api/nonexistent")
+            assert response.status_code == 404
+
+    @pytest.mark.asyncio
+    async def test_handle_method_not_allowed(self, server, sample_endpoints):
+        server.register_endpoints(sample_endpoints)
+        app = server._create_app()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://test") as client:
+            response = await client.post("/api/hello")
+            assert response.status_code == 404
+
+    @pytest.mark.asyncio
+    async def test_response_headers(self, server):
+        endpoint = Endpoint(
+            path="/api/headers",
+            method="GET",
+            response={
+                "status_code": 200,
+                "body": {"test": "value"},
+                "headers": {"X-Custom-Header": "custom-value"}
+            }
+        )
+        server.register_endpoint(endpoint)
+        app = server._create_app()
+        transport = ASGITransport(app=app)
+        async with AsyncClient(transport=transport, base_url="http://test") as client:
+            response = await client.get("/api/headers")
+            assert response.status_code == 200
+            assert response.headers.get("X-Custom-Header") == "custom-value"
+
+    def test_build_response_with_templating(self, server):
+        endpoint = Endpoint(
+            path="/api/test",
+            method="GET",
+            response={
+                "status_code": 200,
+                "body": {
+                    "id": "{{request.path.id}}",
+                    "uuid": "{{uuid}}"
+                }
+            }
+        )
+        context = {
+            "request": {"path": {"id": "123"}},
+            "uuid": "test-uuid"
+        }
+        response = server._build_response(endpoint, context)
+        assert response["status_code"] == 200
+        assert response["body"]["id"] == "123"
+        assert response["body"]["uuid"] == "test-uuid"