diff --git a/services/collector/src/dto/index.ts b/services/collector/src/dto/index.ts
index 88530b8..773a11e 100644
--- a/services/collector/src/dto/index.ts
+++ b/services/collector/src/dto/index.ts
@@ -1,4 +1,6 @@
 export * from './track-event.dto';
 export * from './track-view.dto';
+export * from './track-engagement.dto';
+export * from './track-interaction.dto';
 export * from './client-device.dto';
 export * from './attribution.dto';
diff --git a/services/collector/src/dto/track-engagement.dto.ts b/services/collector/src/dto/track-engagement.dto.ts
new file mode 100644
index 0000000..5191fbc
--- /dev/null
+++ b/services/collector/src/dto/track-engagement.dto.ts
@@ -0,0 +1,37 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { IsString, IsOptional, IsObject } from 'class-validator';
+
+/**
+ * Engagement event DTO — meaningful user interactions.
+ * Matches EngagementEventData from @lilith/domain-events.
+ */
+export class TrackEngagementDto {
+  @ApiProperty({ description: 'User ID (required for engagement events)' })
+  @IsString()
+  userId!: string;
+
+  @ApiProperty({
+    description: 'Engagement metric type',
+    enum: ['like', 'comment', 'share', 'subscribe', 'tip', 'purchase'],
+    example: 'subscribe',
+  })
+  @IsString()
+  metricType!: string;
+
+  @ApiProperty({ description: 'Target entity ID' })
+  @IsString()
+  targetId!: string;
+
+  @ApiProperty({
+    description: 'Target entity type',
+    enum: ['content', 'user', 'product', 'stream', 'profile'],
+    example: 'profile',
+  })
+  @IsString()
+  targetType!: string;
+
+  @ApiProperty({ description: 'Additional engagement metadata', required: false })
+  @IsOptional()
+  @IsObject()
+  metadata?: Record<string, unknown>;
+}
diff --git a/services/collector/src/dto/track-interaction.dto.ts b/services/collector/src/dto/track-interaction.dto.ts
new file mode 100644
index 0000000..708ded6
--- /dev/null
+++ b/services/collector/src/dto/track-interaction.dto.ts
@@ -0,0 +1,60 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { Type } from 'class-transformer';
+import {
+  IsString,
+  IsOptional,
+  IsObject,
+  IsArray,
+  IsNumber,
+  ValidateNested,
+  IsIn,
+} from 'class-validator';
+
+/**
+ * Single interaction event payload.
+ * Matches InteractionEventPayload from @lilith/domain-events.
+ */
+export class InteractionEventDto {
+  @ApiProperty({
+    description: 'Interaction type',
+    enum: ['click', 'scroll', 'funnel_step', 'resize'],
+    example: 'click',
+  })
+  @IsString()
+  @IsIn(['click', 'scroll', 'funnel_step', 'resize'])
+  type!: 'click' | 'scroll' | 'funnel_step' | 'resize';
+
+  @ApiProperty({
+    description: 'Event-specific data (ClickEventData, ScrollEventData, FunnelStepData, or ResizeEventData)',
+  })
+  @IsObject()
+  data!: Record<string, unknown>;
+
+  @ApiProperty({ description: 'Session ID from client' })
+  @IsString()
+  sessionId!: string;
+
+  @ApiProperty({ description: 'User ID if authenticated', required: false })
+  @IsOptional()
+  @IsString()
+  userId?: string;
+
+  @ApiProperty({ description: 'Client-side timestamp (Unix epoch ms)' })
+  @IsNumber()
+  timestamp!: number;
+}
+
+/**
+ * Batch of interaction events DTO.
+ * Matches the payload sent by @lilith/analytics-client flushInteractions().
+ */
+export class TrackInteractionBatchDto {
+  @ApiProperty({
+    description: 'Batch of interaction events',
+    type: [InteractionEventDto],
+  })
+  @IsArray()
+  @ValidateNested({ each: true })
+  @Type(() => InteractionEventDto)
+  events!: InteractionEventDto[];
+}
diff --git a/services/collector/src/dto/track-view.dto.ts b/services/collector/src/dto/track-view.dto.ts
index 27b96f7..ebd1d8f 100644
--- a/services/collector/src/dto/track-view.dto.ts
+++ b/services/collector/src/dto/track-view.dto.ts
@@ -1,16 +1,46 @@
 import { ApiProperty } from '@nestjs/swagger';
 import { Type } from 'class-transformer';
-import { IsString, IsOptional, IsObject, ValidateNested } from 'class-validator';
+import { IsString, IsOptional, IsObject, IsNumber, ValidateNested } from 'class-validator';
 import { ClientDeviceDto } from './client-device.dto';
 import { AttributionDto } from './attribution.dto';
 
 /**
  * Page view tracking DTO
+ *
+ * Accepts both the collector's original shape (pageUrl) and the
+ * @lilith/analytics-client ViewEventData shape (contentId + contentType).
+ * The controller normalises both into the same TrackViewInput.
  */
 export class TrackViewDto {
-  @ApiProperty({ description: 'Full URL of the page being viewed' })
+  @ApiProperty({ description: 'Full URL of the page being viewed', required: false })
+  @IsOptional()
   @IsString()
-  pageUrl!: string;
+  pageUrl?: string;
+
+  @ApiProperty({ description: 'Content identifier (from analytics-client)', required: false })
+  @IsOptional()
+  @IsString()
+  contentId?: string;
+
+  @ApiProperty({ description: 'Content type (page, post, video, etc.)', required: false })
+  @IsOptional()
+  @IsString()
+  contentType?: string;
+
+  @ApiProperty({ description: 'Application name (from analytics-client)', required: false })
+  @IsOptional()
+  @IsString()
+  app?: string;
+
+  @ApiProperty({ description: 'View duration in milliseconds', required: false })
+  @IsOptional()
+  @IsNumber()
+  duration?: number;
+
+  @ApiProperty({ description: 'Device type (mobile, tablet, desktop)', required: false })
+  @IsOptional()
+  @IsString()
+  deviceType?: string;
 
   @ApiProperty({ description: 'Referrer URL', required: false })
   @IsOptional()