lukeautry · jefflembeck · Mar 14, 2026
diff --git a/packages/cli/src/swagger/specGenerator2.ts b/packages/cli/src/swagger/specGenerator2.ts
@@ -18,6 +18,32 @@ export class SpecGenerator2 extends SpecGenerator {
     super(metadata, config);
   }
 
+  // In Swagger 2.0, exclusiveMinimum/exclusiveMaximum are boolean modifiers on minimum/maximum.
+  private transformValidatorsForSchema(validators: Tsoa.Validators): Record<string, unknown> {
+    if (validators.exclusiveMinimum !== undefined && validators.minimum !== undefined) {
+      throw new Error('Cannot use both @minimum and @exclusiveMinimum in Swagger 2.0. Use one or the other, or target OpenAPI 3.1.');
+    }
+    if (validators.exclusiveMaximum !== undefined && validators.maximum !== undefined) {
+      throw new Error('Cannot use both @maximum and @exclusiveMaximum in Swagger 2.0. Use one or the other, or target OpenAPI 3.1.');
+    }
+
+    const result: Record<string, unknown> = {};
+    Object.keys(validators)
+      .filter(shouldIncludeValidatorInSchema)
+      .forEach(key => {
+        if (key === 'exclusiveMinimum') {
+          result['minimum'] = validators.exclusiveMinimum!.value;
+          result['exclusiveMinimum'] = true;
+        } else if (key === 'exclusiveMaximum') {
+          result['maximum'] = validators.exclusiveMaximum!.value;
+          result['exclusiveMaximum'] = true;
+        } else {
+          result[key] = validators[key]!.value;
+        }
+      });
+    return result;
+  }
+
   public GetSpec() {
     let spec: Swagger.Spec2 = {
       basePath: normalisePath(this.config.basePath as string, '/', undefined, false),
@@ -129,14 +155,7 @@ export class SpecGenerator2 extends SpecGenerator {
       } else if (referenceType.dataType === 'refAlias') {
         const swaggerType = this.getSwaggerType(referenceType.type);
         const format = referenceType.format as Swagger.DataFormat;
-        const validators = Object.keys(referenceType.validators)
-          .filter(shouldIncludeValidatorInSchema)
-          .reduce((acc, key) => {
-            return {
-              ...acc,
-              [key]: referenceType.validators[key]!.value,
-            };
-          }, {});
+        const validators = this.transformValidatorsForSchema(referenceType.validators);
 
         definitions[referenceType.refName] = {
           ...(swaggerType as Swagger.Schema2),
@@ -365,12 +384,7 @@ export class SpecGenerator2 extends SpecGenerator {
       return parameter;
     }
 
-    const validatorObjs: Partial<Record<Tsoa.SchemaValidatorKey, unknown>> = {};
-    Object.keys(source.validators)
-      .filter(shouldIncludeValidatorInSchema)
-      .forEach(key => {
-        validatorObjs[key] = source.validators[key]!.value;
-      });
+    const validatorObjs = this.transformValidatorsForSchema(source.validators);
 
     if (source.in === 'body' && source.type.dataType === 'array') {
       parameter.schema = {
@@ -414,11 +428,8 @@ export class SpecGenerator2 extends SpecGenerator {
       if (!swaggerType.$ref) {
         swaggerType.default = property.default;
 
-        Object.keys(property.validators)
-          .filter(shouldIncludeValidatorInSchema)
-          .forEach(key => {
-            swaggerType = { ...swaggerType, [key]: property.validators[key]!.value };
-          });
+        const propertyValidators = this.transformValidatorsForSchema(property.validators);
+        swaggerType = { ...swaggerType, ...propertyValidators };
       }
       if (property.deprecated) {
         swaggerType['x-deprecated'] = true;

diff --git a/packages/cli/src/swagger/specGenerator3.ts b/packages/cli/src/swagger/specGenerator3.ts
@@ -27,6 +27,33 @@ export class SpecGenerator3 extends SpecGenerator {
     super(metadata, config);
   }
 
+  // In OAS 3.0, exclusiveMinimum/exclusiveMaximum are boolean modifiers on minimum/maximum.
+  // OAS 3.1 overrides this to pass through numeric values directly.
+  protected transformValidatorsForSchema(validators: Tsoa.Validators): Record<string, unknown> {
+    if (validators.exclusiveMinimum !== undefined && validators.minimum !== undefined) {
+      throw new Error('Cannot use both @minimum and @exclusiveMinimum in OpenAPI 3.0. Use one or the other, or target OpenAPI 3.1.');
+    }
+    if (validators.exclusiveMaximum !== undefined && validators.maximum !== undefined) {
+      throw new Error('Cannot use both @maximum and @exclusiveMaximum in OpenAPI 3.0. Use one or the other, or target OpenAPI 3.1.');
+    }
+
+    const result: Record<string, unknown> = {};
+    Object.keys(validators)
+      .filter(shouldIncludeValidatorInSchema)
+      .forEach(key => {
+        if (key === 'exclusiveMinimum') {
+          result['minimum'] = validators.exclusiveMinimum!.value;
+          result['exclusiveMinimum'] = true;
+        } else if (key === 'exclusiveMaximum') {
+          result['maximum'] = validators.exclusiveMaximum!.value;
+          result['exclusiveMaximum'] = true;
+        } else {
+          result[key] = validators[key]!.value;
+        }
+      });
+    return result;
+  }
+
   public GetSpec(): Swagger.Spec3 {
     let spec: Swagger.Spec30 = {
       openapi: '3.0.0',
@@ -214,14 +241,7 @@ export class SpecGenerator3 extends SpecGenerator {
       } else if (referenceType.dataType === 'refAlias') {
         const swaggerType = this.getSwaggerType(referenceType.type);
         const format = referenceType.format as Swagger.DataFormat;
-        const validators = Object.keys(referenceType.validators)
-          .filter(shouldIncludeValidatorInSchema)
-          .reduce((acc, key) => {
-            return {
-              ...acc,
-              [key]: referenceType.validators[key]!.value,
-            };
-          }, {});
+        const validators = this.transformValidatorsForSchema(referenceType.validators);
 
         schema[referenceType.refName] = {
           ...(swaggerType as Swagger.Schema3),
@@ -448,14 +468,7 @@ export class SpecGenerator3 extends SpecGenerator {
   }
 
   protected buildMediaType(controllerName: string, method: Tsoa.Method, parameter: Tsoa.Parameter): Swagger.MediaType {
-    const validators = Object.keys(parameter.validators)
-      .filter(shouldIncludeValidatorInSchema)
-      .reduce((acc, key) => {
-        return {
-          ...acc,
-          [key]: parameter.validators[key]!.value,
-        };
-      }, {});
+    const validators = this.transformValidatorsForSchema(parameter.validators);
 
     const mediaType: Swagger.MediaType = {
       schema: {
@@ -516,12 +529,7 @@ export class SpecGenerator3 extends SpecGenerator {
       return Object.assign(parameter, this.buildExamples(source));
     }
 
-    const validatorObjs: { [key in Tsoa.SchemaValidatorKey]?: unknown } = {};
-    Object.keys(source.validators)
-      .filter(shouldIncludeValidatorInSchema)
-      .forEach(key => {
-        validatorObjs[key] = source.validators[key]!.value;
-      });
+    const validatorObjs = this.transformValidatorsForSchema(source.validators);
 
     if (source.type.dataType === 'any') {
       parameter.schema.type = 'string';
@@ -578,11 +586,8 @@ export class SpecGenerator3 extends SpecGenerator {
       if (!swaggerType.$ref) {
         swaggerType.default = property.default;
 
-        Object.keys(property.validators)
-          .filter(shouldIncludeValidatorInSchema)
-          .forEach(key => {
-            swaggerType = { ...swaggerType, [key]: property.validators[key]!.value };
-          });
+        const propertyValidators = this.transformValidatorsForSchema(property.validators);
+        swaggerType = { ...swaggerType, ...propertyValidators };
       }
       if (property.deprecated) {
         swaggerType.deprecated = true;

diff --git a/packages/cli/src/swagger/specGenerator31.ts b/packages/cli/src/swagger/specGenerator31.ts
@@ -4,6 +4,7 @@ import { merge as deepMerge } from 'ts-deepmerge';
 
 import { ExtendedSpecConfig } from '../cli';
 import { UnspecifiedObject } from '../utils/unspecifiedObject';
+import { shouldIncludeValidatorInSchema } from '../utils/validatorUtils';
 import { SpecGenerator3 } from './specGenerator3';
 
 /**
@@ -50,6 +51,17 @@ export class SpecGenerator31 extends SpecGenerator3 {
     return spec;
   }
 
+  // In OAS 3.1, exclusiveMinimum/exclusiveMaximum are standalone numbers.
+  protected override transformValidatorsForSchema(validators: Tsoa.Validators): Record<string, unknown> {
+    const result: Record<string, unknown> = {};
+    Object.keys(validators)
+      .filter(shouldIncludeValidatorInSchema)
+      .forEach(key => {
+        result[key] = validators[key]!.value;
+      });
+    return result;
+  }
+
   /**
    * Override to add tuple type support (OpenAPI 3.1 feature via prefixItems)
    */

diff --git a/packages/cli/src/utils/validatorUtils.ts b/packages/cli/src/utils/validatorUtils.ts
@@ -53,6 +53,8 @@ export function getParameterValidators(parameter: ts.ParameterDeclaration, param
           break;
         case 'minimum':
         case 'maximum':
+        case 'exclusiveMinimum':
+        case 'exclusiveMaximum':
         case 'minItems':
         case 'maxItems':
         case 'minLength':
@@ -152,6 +154,8 @@ export function getPropertyValidators(property: ts.Node): Tsoa.Validators | unde
           break;
         case 'minimum':
         case 'maximum':
+        case 'exclusiveMinimum':
+        case 'exclusiveMaximum':
         case 'minItems':
         case 'maxItems':
         case 'minLength':
@@ -228,6 +232,8 @@ function getParameterTagSupport() {
     'pattern',
     'minimum',
     'maximum',
+    'exclusiveMinimum',
+    'exclusiveMaximum',
     'minDate',
     'maxDate',
     'title',

diff --git a/packages/runtime/src/routeGeneration/templateHelpers.ts b/packages/runtime/src/routeGeneration/templateHelpers.ts
@@ -223,6 +223,24 @@ export class ValidationService {
         return;
       }
     }
+    if (validators.exclusiveMinimum && validators.exclusiveMinimum.value !== undefined) {
+      if (validators.exclusiveMinimum.value >= numberValue) {
+        fieldErrors[parent + name] = {
+          message: validators.exclusiveMinimum.errorMsg || `exclusiveMin ${validators.exclusiveMinimum.value}`,
+          value,
+        };
+        return;
+      }
+    }
+    if (validators.exclusiveMaximum && validators.exclusiveMaximum.value !== undefined) {
+      if (validators.exclusiveMaximum.value <= numberValue) {
+        fieldErrors[parent + name] = {
+          message: validators.exclusiveMaximum.errorMsg || `exclusiveMax ${validators.exclusiveMaximum.value}`,
+          value,
+        };
+        return;
+      }
+    }
     return numberValue;
   }
 
@@ -266,6 +284,24 @@ export class ValidationService {
         return;
       }
     }
+    if (validators.exclusiveMinimum && validators.exclusiveMinimum.value !== undefined) {
+      if (validators.exclusiveMinimum.value >= numberValue) {
+        fieldErrors[parent + name] = {
+          message: validators.exclusiveMinimum.errorMsg || `exclusiveMin ${validators.exclusiveMinimum.value}`,
+          value,
+        };
+        return;
+      }
+    }
+    if (validators.exclusiveMaximum && validators.exclusiveMaximum.value !== undefined) {
+      if (validators.exclusiveMaximum.value <= numberValue) {
+        fieldErrors[parent + name] = {
+          message: validators.exclusiveMaximum.errorMsg || `exclusiveMax ${validators.exclusiveMaximum.value}`,
+          value,
+        };
+        return;
+      }
+    }
     return numberValue;
   }
 
@@ -940,13 +976,17 @@ export interface IntegerValidator {
   isLong?: { errorMsg?: string };
   minimum?: { value: number; errorMsg?: string };
   maximum?: { value: number; errorMsg?: string };
+  exclusiveMinimum?: { value: number; errorMsg?: string };
+  exclusiveMaximum?: { value: number; errorMsg?: string };
 }
 
 export interface FloatValidator {
   isFloat?: { errorMsg?: string };
   isDouble?: { errorMsg?: string };
   minimum?: { value: number; errorMsg?: string };
   maximum?: { value: number; errorMsg?: string };
+  exclusiveMinimum?: { value: number; errorMsg?: string };
+  exclusiveMaximum?: { value: number; errorMsg?: string };
 }
 
 export interface DateValidator {

diff --git a/packages/runtime/src/swagger/swagger.ts b/packages/runtime/src/swagger/swagger.ts
@@ -339,9 +339,7 @@ export namespace Swagger {
     default?: string | boolean | number | unknown;
     multipleOf?: number;
     maximum?: number;
-    exclusiveMaximum?: number;
     minimum?: number;
-    exclusiveMinimum?: number;
     maxLength?: number;
     minLength?: number;
     pattern?: string;
@@ -368,8 +366,10 @@ export namespace Swagger {
     items?: BaseSchema;
   }
 
-  export interface Schema31 extends Omit<Schema3, 'items' | 'properties' | 'additionalProperties' | 'discriminator' | 'anyOf' | 'allOf'> {
+  export interface Schema31 extends Omit<Schema3, 'items' | 'properties' | 'additionalProperties' | 'discriminator' | 'anyOf' | 'allOf' | 'exclusiveMinimum' | 'exclusiveMaximum'> {
     examples?: unknown[];
+    exclusiveMinimum?: number;
+    exclusiveMaximum?: number;
 
     properties?: { [key: string]: Schema31 };
     additionalProperties?: boolean | Schema31;
@@ -397,13 +397,17 @@ export namespace Swagger {
     allOf?: BaseSchema[];
     deprecated?: boolean;
     properties?: { [propertyName: string]: Schema3 };
+    exclusiveMinimum?: boolean;
+    exclusiveMaximum?: boolean;
   }
 
   export interface Schema2 extends BaseSchema {
     type?: DataType;
     properties?: { [propertyName: string]: Schema2 };
     ['x-nullable']?: boolean;
     ['x-deprecated']?: boolean;
+    exclusiveMinimum?: boolean;
+    exclusiveMaximum?: boolean;
   }
 
   export interface Header {

diff --git a/tests/fixtures/testModel.ts b/tests/fixtures/testModel.ts
@@ -880,6 +880,14 @@ export class ValidateModel {
    * @minimum 5
    */
   public numberMin5!: number;
+  /**
+   * @exclusiveMinimum 5
+   */
+  public numberExclusiveMin5!: number;
+  /**
+   * @exclusiveMaximum 10
+   */
+  public numberExclusiveMax10!: number;
   /**
    * @maxLength 10
    */
@@ -990,6 +998,14 @@ export class ValidateModel {
      * @minimum 5
      */
     numberMin5: number;
+    /**
+     * @exclusiveMinimum 5
+     */
+    numberExclusiveMin5: number;
+    /**
+     * @exclusiveMaximum 10
+     */
+    numberExclusiveMax10: number;
     /**
      * @maxLength 10
      */

diff --git a/tests/fixtures/testModel31.ts b/tests/fixtures/testModel31.ts
@@ -872,6 +872,14 @@ export class ValidateModel {
    * @minimum 5
    */
   public numberMin5!: number;
+  /**
+   * @exclusiveMinimum 5
+   */
+  public numberExclusiveMin5!: number;
+  /**
+   * @exclusiveMaximum 10
+   */
+  public numberExclusiveMax10!: number;
   /**
    * @maxLength 10
    */
@@ -982,6 +990,14 @@ export class ValidateModel {
      * @minimum 5
      */
     numberMin5: number;
+    /**
+     * @exclusiveMinimum 5
+     */
+    numberExclusiveMin5: number;
+    /**
+     * @exclusiveMaximum 10
+     */
+    numberExclusiveMax10: number;
     /**
      * @maxLength 10
      */