diff --git a/openspec/changes/code-review-fix/tasks.md b/openspec/changes/code-review-fix/tasks.md
index fbb9a81..32ae428 100644
--- a/openspec/changes/code-review-fix/tasks.md
+++ b/openspec/changes/code-review-fix/tasks.md
@@ -82,7 +82,7 @@
 ## 9. Frontend — Shared Types & Type Safety
 
 - [x] 9.1 `[sonnet]` Create `src/types/candles.ts` with `Candle` interface
-- [ ] 9.2 `[sonnet]` Create `src/types/annotations.ts` with `Annotation`, `AnnotationType`, `Geometry` interfaces
+- [x] 9.2 `[sonnet]` Create `src/types/annotations.ts` with `Annotation`, `AnnotationType`, `Geometry` interfaces
 - [ ] 9.3 `[sonnet]` Create `src/types/charts.ts` with `Chart` interface
 - [ ] 9.4 `[sonnet]` Create `src/types/predictions.ts` with `PredictionSpan`, `PredictionState`, `ModelInfo` interfaces
 - [ ] 9.5 `[sonnet]` Create `src/types/span-annotations.ts` with `SpanAnnotation`, `SpanLabelType`, `SubSpan` interfaces
diff --git a/src/types/annotations.ts b/src/types/annotations.ts
new file mode 100644
index 0000000..22dd726
--- /dev/null
+++ b/src/types/annotations.ts
@@ -0,0 +1,35 @@
+/**
+ * Annotation types for point and line/rectangle annotations on charts.
+ *
+ * Geometry fields use Unix epoch seconds for time values.
+ * startTime / endTime correspond to candle timestamps.
+ * startPrice / endPrice correspond to price axis values.
+ */
+
+export interface Geometry {
+  startTime?: number;
+  startPrice?: number;
+  endTime?: number;
+  endPrice?: number;
+}
+
+export interface AnnotationType {
+  id: number;
+  name: string;
+  display_name: string;
+  color: string;
+  category: string; // 'marker' | 'line' | 'rectangle'
+  icon: string | null;
+  is_active: boolean;
+  created_at?: number | Date;
+}
+
+export interface Annotation {
+  id: number;
+  chart_id: number;
+  timestamp: number; // Unix epoch seconds
+  label_type: string;
+  color: string | null;
+  geometry: Geometry | null;
+  created_at: number | Date;
+}