diff --git a/apps/mark/src/lib/features/branches/BranchCard.svelte b/apps/mark/src/lib/features/branches/BranchCard.svelte
index b6a3b766..1077d7cd 100644
--- a/apps/mark/src/lib/features/branches/BranchCard.svelte
+++ b/apps/mark/src/lib/features/branches/BranchCard.svelte
@@ -309,6 +309,7 @@
     scope: 'branch' | 'commit';
     comments: number;
     annotations: number;
+    warnings: number;
   };
   let timelineReviewDetailsById = $state<Record<string, TimelineReviewDetails>>({});
   let reviewDetailsLoadVersion = 0;
@@ -864,11 +865,15 @@
 
           let comments = 0;
           let annotations = 0;
+          let warnings = 0;
           for (const comment of fullReview.comments) {
             if (comment.commentType === 'information') {
               annotations += 1;
             } else {
               comments += 1;
+              if (comment.commentType === 'warning') {
+                warnings += 1;
+              }
             }
           }
 
@@ -877,6 +882,7 @@
             scope: fullReview.scope,
             comments,
             annotations,
+            warnings,
           };
           return { id: review.id, details };
         } catch (e) {
diff --git a/apps/mark/src/lib/features/diff/DiffCommentsSection.svelte b/apps/mark/src/lib/features/diff/DiffCommentsSection.svelte
index 1e7d1032..e5810171 100644
--- a/apps/mark/src/lib/features/diff/DiffCommentsSection.svelte
+++ b/apps/mark/src/lib/features/diff/DiffCommentsSection.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { Bot, Check, Copy, MessageSquare, Trash2 } from 'lucide-svelte';
+  import { AlertTriangle, Bot, Check, Copy, MessageSquare, Trash2 } from 'lucide-svelte';
   import type { Comment } from '../../types';
   import { formatLineRange, truncateText } from './diffModalHelpers';
 
@@ -68,12 +68,22 @@
             style="padding-left: 8px"
             onclick={() => onSelectComment(comment)}
           >
-            <span class="comment-icon" class:agent-comment={comment.author === 'agent'}>
+            <span class="comment-icons">
               {#if comment.author === 'agent'}
-                <Bot size={12} />
-              {:else}
-                <MessageSquare size={12} />
+                <span class="comment-icon agent-icon">
+                  <Bot size={12} />
+                </span>
               {/if}
+              <span
+                class="comment-icon"
+                class:comment-icon-warning={comment.commentType === 'warning'}
+              >
+                {#if comment.commentType === 'warning'}
+                  <AlertTriangle size={12} />
+                {:else}
+                  <MessageSquare size={12} />
+                {/if}
+              </span>
             </span>
             <span class="comment-details">
               <span class="comment-location">
@@ -220,18 +230,30 @@
     gap: 2px !important;
     padding-top: 6px !important;
     padding-bottom: 6px !important;
-    padding-left: 28px !important;
+    padding-left: 40px !important;
     width: 100%;
   }
 
-  .comment-icon {
+  .comment-icons {
     position: absolute;
     left: 8px;
     top: 8px;
+    display: flex;
+    align-items: center;
+    gap: 3px;
+  }
+
+  .comment-icon {
+    display: flex;
+    align-items: center;
     color: var(--text-faint);
   }
 
-  .comment-icon.agent-comment {
+  .comment-icon.agent-icon {
+    color: var(--status-modified);
+  }
+
+  .comment-icon.comment-icon-warning {
     color: var(--status-modified);
   }
 
diff --git a/apps/mark/src/lib/features/diff/DiffFileTreeSection.svelte b/apps/mark/src/lib/features/diff/DiffFileTreeSection.svelte
index 6127198b..07d3c17e 100644
--- a/apps/mark/src/lib/features/diff/DiffFileTreeSection.svelte
+++ b/apps/mark/src/lib/features/diff/DiffFileTreeSection.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import {
+    AlertTriangle,
     Check,
     RotateCcw,
     ChevronRight,
@@ -228,7 +229,16 @@
           {@render fileIcon(node.file, showReviewedSection)}
           <span class="file-name">{node.name}</span>
           {#if node.file.commentCount > 0}
-            <span class="comment-indicator"><MessageSquare size={12} /></span>
+            <span
+              class="comment-indicator"
+              class:comment-indicator-warning={node.file.commentTypes.includes('warning')}
+            >
+              {#if node.file.commentTypes.includes('warning')}
+                <AlertTriangle size={12} />
+              {:else}
+                <MessageSquare size={12} />
+              {/if}
+            </span>
           {/if}
           {#if searchState?.state.isOpen && searchState.state.fileResults.has(node.file.path)}
             {@const resultCount =
@@ -525,4 +535,8 @@
     margin-left: auto;
     padding-left: 4px;
   }
+
+  .comment-indicator.comment-indicator-warning {
+    color: var(--status-modified);
+  }
 </style>
diff --git a/apps/mark/src/lib/features/timeline/BranchTimeline.svelte b/apps/mark/src/lib/features/timeline/BranchTimeline.svelte
index 77a4e3a3..ef7c94ec 100644
--- a/apps/mark/src/lib/features/timeline/BranchTimeline.svelte
+++ b/apps/mark/src/lib/features/timeline/BranchTimeline.svelte
@@ -11,7 +11,7 @@
   import { FileText, GitCommitVertical, FileSearch } from 'lucide-svelte';
   import type { BranchTimeline as BranchTimelineData } from '../../types';
   import TimelineRow from './TimelineRow.svelte';
-  import type { TimelineItemType } from './TimelineRow.svelte';
+  import type { TimelineItemType, TimelineBadge } from './TimelineRow.svelte';
   import {
     collectRunningSessionIds,
     createLiveSessionHints,
@@ -48,7 +48,14 @@
     onDeleteReview?: (reviewId: string, sessionId?: string) => void;
     onDeleteImage?: (imageId: string) => void;
     /** Optional per-review breakdown of visible comments vs hold-to-reveal annotations. */
-    reviewCommentBreakdown?: Record<string, { comments: number; annotations: number }>;
+    reviewCommentBreakdown?: Record<
+      string,
+      {
+        comments: number;
+        annotations: number;
+        warnings?: number;
+      }
+    >;
     onNewNote?: () => void;
     onNewCommit?: () => void;
     onNewReview?: (e: MouseEvent) => void;
@@ -113,6 +120,7 @@
     reviewId?: string;
     imageId?: string;
     imageFilename?: string;
+    badges?: TimelineBadge[];
     /** When set, delete button is shown but disabled with this tooltip. */
     deleteDisabledReason?: string;
   };
@@ -122,10 +130,6 @@
     return text.replace(/<(action|branch-history)>[\s\S]*?<\/\1>/g, '').trim();
   }
 
-  function formatCount(count: number, singular: string): string {
-    return `${count} ${singular}${count === 1 ? '' : 's'}`;
-  }
-
   let runningSessionIds = $derived.by(() => collectRunningSessionIds(timeline, pendingItems));
 
   $effect(() => {
@@ -233,30 +237,39 @@
       const isFailed = !isRunning && !!review.sessionId && totalCount === 0;
       const isDeleting = deletingReviewIds.has(review.id);
       const liveHint = review.sessionId ? liveSessionHints[review.sessionId] : undefined;
-      const countParts: string[] = [];
-      if (commentCount > 0) countParts.push(formatCount(commentCount, 'comment'));
-      if (annotationCount > 0) countParts.push(formatCount(annotationCount, 'annotation'));
+
+      // Build badges: warnings get their own badge, everything else is a comment
+      const warningCount = breakdown?.warnings ?? 0;
+      const nonWarningCount = commentCount - warningCount;
+
+      const badges: TimelineBadge[] = [];
+      if (warningCount > 0) {
+        badges.push({ icon: 'warning', count: warningCount });
+      }
+      if (nonWarningCount > 0) {
+        badges.push({ icon: 'comment', count: nonWarningCount });
+      }
 
       let type: TimelineItemType;
-      let secondaryMeta: string | undefined;
+      let meta: string | undefined;
 
       if (isFailed) {
         type = 'failed-review';
-        secondaryMeta = 'Session finished — no comments created';
+        meta = 'Session finished — no comments created';
       } else if (isRunning) {
         type = 'generating-review';
-        secondaryMeta = liveHint ?? 'Generating review';
+        meta = liveHint ?? 'Generating review';
       } else {
         type = 'review';
-        secondaryMeta = formatRelativeTimeMs(review.createdAt);
+        meta = formatRelativeTimeMs(review.createdAt);
       }
 
       all.push({
         key: `review-${review.id}`,
         type,
         title: review.title || 'Code Review',
-        meta: countParts.length > 0 ? countParts.join(' + ') : undefined,
-        secondaryMeta: isDeleting ? 'Deleting...' : secondaryMeta,
+        meta: isDeleting ? 'Deleting...' : meta,
+        badges: badges.length > 0 ? badges : undefined,
         deleting: isDeleting,
         timestamp: Math.floor(review.createdAt / 1000),
         sessionId: review.sessionId ?? undefined,
@@ -418,6 +431,7 @@
         title={item.title}
         meta={item.meta}
         secondaryMeta={item.secondaryMeta}
+        badges={item.badges}
         deleting={item.deleting}
         isLast={index === items.length - 1 &&
           !onNewNote &&
diff --git a/apps/mark/src/lib/features/timeline/TimelineRow.svelte b/apps/mark/src/lib/features/timeline/TimelineRow.svelte
index e427deea..c6226094 100644
--- a/apps/mark/src/lib/features/timeline/TimelineRow.svelte
+++ b/apps/mark/src/lib/features/timeline/TimelineRow.svelte
@@ -28,11 +28,17 @@
     | 'failed-review'
     | 'image';
 
+  export type TimelineBadge = {
+    icon: 'comment' | 'warning';
+    count: number;
+  };
+
   interface Props {
     type: TimelineItemType;
     title: string;
     meta?: string;
     secondaryMeta?: string;
+    badges?: TimelineBadge[];
     deleting?: boolean;
     isLast?: boolean;
     sessionId?: string;
@@ -48,6 +54,7 @@
     title,
     meta,
     secondaryMeta,
+    badges,
     deleting = false,
     isLast = false,
     sessionId,
@@ -134,7 +141,7 @@
       <span class="timeline-title" class:skeleton-title={isPending} class:failed-title={isFailed}
         >{title}</span
       >
-      {#if meta || secondaryMeta}
+      {#if meta || secondaryMeta || (badges && badges.length > 0)}
         <div class="timeline-meta">
           {#if meta}
             <span class="meta-item">{meta}</span>
@@ -142,6 +149,18 @@
           {#if secondaryMeta}
             <span class="meta-item meta-sha" class:failed-meta={isFailed}>{secondaryMeta}</span>
           {/if}
+          {#if badges}
+            {#each badges as badge}
+              <span class="meta-badge">
+                {#if badge.icon === 'warning'}
+                  <AlertTriangle size={10} />
+                {:else}
+                  <MessageSquare size={10} />
+                {/if}
+                <span>{badge.count}</span>
+              </span>
+            {/each}
+          {/if}
         </div>
       {/if}
     </div>
@@ -318,7 +337,7 @@
 
   .timeline-meta {
     display: flex;
-    align-items: baseline;
+    align-items: center;
     gap: 8px;
     margin-top: 3px;
   }
@@ -332,6 +351,20 @@
     font-family: 'SF Mono', 'Menlo', 'Monaco', 'Courier New', monospace;
   }
 
+  .meta-badge {
+    display: inline-flex;
+    align-items: center;
+    gap: 3px;
+    padding: 2px 7px;
+    border-radius: 8px;
+    background: none;
+    border: 1px solid var(--border-subtle);
+    color: var(--text-muted);
+    font-size: calc(var(--size-xs) - 1px);
+    font-weight: 600;
+    line-height: 1;
+  }
+
   /* Actions container — visible on row hover */
   .timeline-actions {
     display: flex;
diff --git a/packages/diff-viewer/src/lib/utils/diffModalHelpers.ts b/packages/diff-viewer/src/lib/utils/diffModalHelpers.ts
index 2193f56e..55e83c36 100644
--- a/packages/diff-viewer/src/lib/utils/diffModalHelpers.ts
+++ b/packages/diff-viewer/src/lib/utils/diffModalHelpers.ts
@@ -1,4 +1,4 @@
-import type { Comment, FileDiffSummary } from '../types';
+import type { Comment, CommentType, FileDiffSummary } from '../types';
 import { fileSummaryPath } from '../state/diffViewerState.svelte';
 
 export interface FileEntry {
@@ -6,6 +6,8 @@ export interface FileEntry {
   status: 'added' | 'deleted' | 'modified' | 'renamed';
   isReviewed: boolean;
   commentCount: number;
+  /** The distinct comment types present on this file (e.g. 'warning', 'suggestion'). */
+  commentTypes: CommentType[];
 }
 
 export interface TreeNode {
@@ -30,8 +32,17 @@ export function buildFileEntries(
 ): FileEntry[] {
   const reviewedSet = new Set(reviewedPaths);
   const commentCounts = new Map<string, number>();
+  const commentTypesByFile = new Map<string, Set<CommentType>>();
   for (const comment of comments) {
     commentCounts.set(comment.path, (commentCounts.get(comment.path) || 0) + 1);
+    if (comment.commentType) {
+      let types = commentTypesByFile.get(comment.path);
+      if (!types) {
+        types = new Set();
+        commentTypesByFile.set(comment.path, types);
+      }
+      types.add(comment.commentType);
+    }
   }
 
   return files.map((summary) => {
@@ -41,6 +52,7 @@ export function buildFileEntries(
       status: fileStatus(summary),
       isReviewed: reviewedSet.has(path),
       commentCount: commentCounts.get(path) || 0,
+      commentTypes: [...(commentTypesByFile.get(path) || [])],
     };
   });
 }