diff --git a/src/goals/dto.ts b/src/goals/dto.ts
new file mode 100644
index 0000000..01c65e3
--- /dev/null
+++ b/src/goals/dto.ts
@@ -0,0 +1,47 @@
+import { IsArray, IsIn, IsOptional, IsString, Length } from 'class-validator';
+
+export const GOAL_STATUSES = ['not_started', 'on_track', 'at_risk', 'achieved', 'abandoned'] as const;
+export type GoalStatusValue = (typeof GOAL_STATUSES)[number];
+
+export class CreateGoalDto {
+  @IsString()
+  @Length(1, 500)
+  horizon!: string;
+
+  @IsString()
+  @Length(1, 500)
+  metric!: string;
+
+  @IsString()
+  @Length(1, 1000)
+  target!: string;
+
+  @IsOptional()
+  @IsArray()
+  milestones?: unknown[];
+}
+
+export class UpdateGoalDto {
+  @IsOptional()
+  @IsString()
+  @Length(1, 500)
+  horizon?: string;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 500)
+  metric?: string;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 1000)
+  target?: string;
+
+  @IsOptional()
+  @IsArray()
+  milestones?: unknown[];
+
+  @IsOptional()
+  @IsIn(GOAL_STATUSES as unknown as string[])
+  status?: GoalStatusValue;
+}