diff --git a/src/opportunities/dto.ts b/src/opportunities/dto.ts
new file mode 100644
index 0000000..35d4e34
--- /dev/null
+++ b/src/opportunities/dto.ts
@@ -0,0 +1,69 @@
+import { IsISO8601, IsNumber, IsOptional, IsString, Length, Max, Min } from 'class-validator';
+
+export class CreateOpportunityDto {
+  @IsString()
+  @Length(1, 128)
+  source!: string;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 64)
+  entityType?: string;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 255)
+  entityId?: string;
+
+  @IsOptional()
+  @IsNumber()
+  @Min(0)
+  valueRangeMin?: number;
+
+  @IsOptional()
+  @IsNumber()
+  @Min(0)
+  valueRangeMax?: number;
+
+  @IsOptional()
+  @IsNumber()
+  @Min(0)
+  @Max(1)
+  probability?: number;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 500)
+  nextAction?: string;
+
+  @IsOptional()
+  @IsISO8601()
+  expiresAt?: string;
+}
+
+export class UpdateOpportunityDto {
+  @IsOptional()
+  @IsNumber()
+  @Min(0)
+  @Max(1)
+  probability?: number;
+
+  @IsOptional()
+  @IsString()
+  @Length(1, 500)
+  nextAction?: string;
+
+  @IsOptional()
+  @IsISO8601()
+  expiresAt?: string;
+
+  @IsOptional()
+  @IsNumber()
+  @Min(0)
+  valueRangeMin?: number;
+
+  @IsOptional()
+  @IsNumber()
+  @Min(0)
+  valueRangeMax?: number;
+}