diff --git a/backend/src/main/java/org/raddatz/familienarchiv/controller/CommentController.java b/backend/src/main/java/org/raddatz/familienarchiv/controller/CommentController.java
new file mode 100644
index 00000000..1373f71f
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/controller/CommentController.java
@@ -0,0 +1,122 @@
+package org.raddatz.familienarchiv.controller;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.dto.CreateCommentDTO;
+import org.raddatz.familienarchiv.model.AppUser;
+import org.raddatz.familienarchiv.model.DocumentComment;
+import org.raddatz.familienarchiv.security.Permission;
+import org.raddatz.familienarchiv.security.RequirePermission;
+import org.raddatz.familienarchiv.service.CommentService;
+import org.raddatz.familienarchiv.service.UserService;
+import org.springframework.http.HttpStatus;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+import java.util.UUID;
+
+@RestController
+@RequiredArgsConstructor
+@Slf4j
+public class CommentController {
+
+    private final CommentService commentService;
+    private final UserService userService;
+
+    // ─── General document comments ────────────────────────────────────────────
+
+    @GetMapping("/api/documents/{documentId}/comments")
+    public List<DocumentComment> getDocumentComments(@PathVariable UUID documentId) {
+        return commentService.getCommentsForDocument(documentId);
+    }
+
+    @PostMapping("/api/documents/{documentId}/comments")
+    @ResponseStatus(HttpStatus.CREATED)
+    @RequirePermission(Permission.ANNOTATE_ALL)
+    public DocumentComment postDocumentComment(
+            @PathVariable UUID documentId,
+            @RequestBody CreateCommentDTO dto,
+            Authentication authentication) {
+        AppUser author = resolveUser(authentication);
+        return commentService.postComment(documentId, null, dto.getContent(), author);
+    }
+
+    @PostMapping("/api/documents/{documentId}/comments/{commentId}/replies")
+    @ResponseStatus(HttpStatus.CREATED)
+    @RequirePermission(Permission.ANNOTATE_ALL)
+    public DocumentComment replyToDocumentComment(
+            @PathVariable UUID documentId,
+            @PathVariable UUID commentId,
+            @RequestBody CreateCommentDTO dto,
+            Authentication authentication) {
+        AppUser author = resolveUser(authentication);
+        return commentService.replyToComment(documentId, commentId, dto.getContent(), author);
+    }
+
+    // ─── Annotation comments ──────────────────────────────────────────────────
+
+    @GetMapping("/api/documents/{documentId}/annotations/{annotationId}/comments")
+    public List<DocumentComment> getAnnotationComments(@PathVariable UUID annotationId) {
+        return commentService.getCommentsForAnnotation(annotationId);
+    }
+
+    @PostMapping("/api/documents/{documentId}/annotations/{annotationId}/comments")
+    @ResponseStatus(HttpStatus.CREATED)
+    @RequirePermission(Permission.ANNOTATE_ALL)
+    public DocumentComment postAnnotationComment(
+            @PathVariable UUID documentId,
+            @PathVariable UUID annotationId,
+            @RequestBody CreateCommentDTO dto,
+            Authentication authentication) {
+        AppUser author = resolveUser(authentication);
+        return commentService.postComment(documentId, annotationId, dto.getContent(), author);
+    }
+
+    @PostMapping("/api/documents/{documentId}/annotations/{annotationId}/comments/{commentId}/replies")
+    @ResponseStatus(HttpStatus.CREATED)
+    @RequirePermission(Permission.ANNOTATE_ALL)
+    public DocumentComment replyToAnnotationComment(
+            @PathVariable UUID documentId,
+            @PathVariable UUID commentId,
+            @RequestBody CreateCommentDTO dto,
+            Authentication authentication) {
+        AppUser author = resolveUser(authentication);
+        return commentService.replyToComment(documentId, commentId, dto.getContent(), author);
+    }
+
+    // ─── Edit and delete (shared) ─────────────────────────────────────────────
+
+    @PatchMapping("/api/documents/{documentId}/comments/{commentId}")
+    @RequirePermission(Permission.ANNOTATE_ALL)
+    public DocumentComment editComment(
+            @PathVariable UUID documentId,
+            @PathVariable UUID commentId,
+            @RequestBody CreateCommentDTO dto,
+            Authentication authentication) {
+        AppUser currentUser = resolveUser(authentication);
+        return commentService.editComment(documentId, commentId, dto.getContent(), currentUser);
+    }
+
+    @DeleteMapping("/api/documents/{documentId}/comments/{commentId}")
+    @ResponseStatus(HttpStatus.NO_CONTENT)
+    public void deleteComment(
+            @PathVariable UUID documentId,
+            @PathVariable UUID commentId,
+            Authentication authentication) {
+        AppUser currentUser = resolveUser(authentication);
+        commentService.deleteComment(documentId, commentId, currentUser);
+    }
+
+    // ─── private helpers ──────────────────────────────────────────────────────
+
+    private AppUser resolveUser(Authentication authentication) {
+        if (authentication == null || !authentication.isAuthenticated()) return null;
+        try {
+            return userService.findByUsername(authentication.getName());
+        } catch (Exception e) {
+            log.warn("Could not resolve user for comment: {}", e.getMessage());
+            return null;
+        }
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/dto/CreateCommentDTO.java b/backend/src/main/java/org/raddatz/familienarchiv/dto/CreateCommentDTO.java
new file mode 100644
index 00000000..9caa4b1a
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/dto/CreateCommentDTO.java
@@ -0,0 +1,8 @@
+package org.raddatz.familienarchiv.dto;
+
+import lombok.Data;
+
+@Data
+public class CreateCommentDTO {
+    private String content;
+}