Created an endpoint which reads current value of a pin.

Proculite.GpioRest/Controllers/GpioController.cs

@@ -0,0 +1,25 @@
+using Microsoft.AspNetCore.Mvc;
+using Proculite.GpioRest.Services;
+
+namespace Proculite.GpioRest.Controllers
+{
+    [Route("/gpio")]
+    public class GpioController : Controller
+    {
+        private readonly GpioService _gpioService;
+
+        public GpioController(GpioService gpioService)
+        {
+            _gpioService = gpioService;
+        }
+
+        [HttpGet("pin-value/{pinNumber}")]
+        public IActionResult PinValue(int pinNumber)
+        {
+            if(!ModelState.IsValid)
+                return BadRequest();
+                
+            return Ok(_gpioService.CurrentPinValue(pinNumber));
+        }
+    }
+}

Proculite.GpioRest/Services/GpioService.cs

@@ -42,5 +42,10 @@ namespace Proculite.GpioRest.Services
                 _gpioController.OpenPin(pin, pinMode, PinValue.Low);
             }
         }
+
+        public PinValue CurrentPinValue(int pinNumber)
+        {
+            return _gpioController.Read(pinNumber);
+        }
     }
 }