diff --git a/src/decisions/dto.ts b/src/decisions/dto.ts
new file mode 100644
index 0000000..eb92b86
--- /dev/null
+++ b/src/decisions/dto.ts
@@ -0,0 +1,56 @@
+import { IsArray, IsISO8601, IsOptional, IsString, Length } from 'class-validator';
+
+export class CreateDecisionDto {
+  @IsString()
+  @Length(1, 2000)
+  context!: string;
+
+  @IsOptional()
+  @IsArray()
+  options?: unknown[];
+
+  @IsOptional()
+  @IsArray()
+  assumptions?: unknown[];
+
+  @IsOptional()
+  @IsArray()
+  evidence?: unknown[];
+
+  @IsOptional()
+  @IsISO8601()
+  reviewDueAt?: string;
+}
+
+export class UpdateDecisionDto {
+  @IsOptional()
+  @IsString()
+  @Length(1, 2000)
+  context?: string;
+
+  @IsOptional()
+  @IsArray()
+  options?: unknown[];
+
+  @IsOptional()
+  @IsArray()
+  assumptions?: unknown[];
+
+  @IsOptional()
+  @IsArray()
+  evidence?: unknown[];
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 500)
+  selectedOption?: string;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 2000)
+  outcomeReview?: string;
+
+  @IsOptional()
+  @IsISO8601()
+  reviewDueAt?: string;
+}