Index: iknow-api/DTOs/ProfDTO.cs
===================================================================
--- iknow-api/DTOs/ProfDTO.cs	(revision ea405569ef29f56fbfc4d77708b6b3faf9286097)
+++ iknow-api/DTOs/ProfDTO.cs	(revision ea405569ef29f56fbfc4d77708b6b3faf9286097)
@@ -0,0 +1,36 @@
+namespace iknow_api.DTOs
+{
+    /// <summary>One subject a professor teaches, with the students enrolled in it.</summary>
+    public class SubjectStudentsDto
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        public string? Code { get; set; }
+        public List<EnrolledStudentDto> Users { get; set; } = new();
+    }
+
+    public class EnrolledStudentDto
+    {
+        /// <summary>users.id - what the grading endpoints expect as StudentId.</summary>
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        /// <summary>users.index - the number a professor actually recognises.</summary>
+        public string? Index { get; set; }
+        /// <summary>0 when the subject has not been graded yet.</summary>
+        public int Grade { get; set; }
+        public string? Semester { get; set; }
+    }
+
+    public class GradeRequestDto
+    {
+        public int StudentId { get; set; }
+        public int SubjectId { get; set; }
+        public int Grade { get; set; }
+    }
+
+    public class GradeResultDto
+    {
+        public bool Ok { get; set; }
+        public string? Message { get; set; }
+    }
+}