diff --git a/src/controllers/flags.ts b/src/controllers/flags.ts
index ae49ab1..dc820ef 100644
--- a/src/controllers/flags.ts
+++ b/src/controllers/flags.ts
@@ -1,4 +1,4 @@
-import { getAllFlags } from '../models/flags';
+import { getAllFlags, checkDuplicateKey, createFlag } from '../models/flags';
 import { Request, Response } from 'express';
 import { IResponse } from '../types/response';
 import { IFlag } from '../types/flags';
@@ -24,3 +24,36 @@ export const getFlagsController = async (
       }
    }
 };
+
+export const createFlagController = async (
+   req: Request,
+   res: Response,
+): Promise<void> => {
+   const flag: IFlag = req.body;
+   try {
+      const isDuplicate = await checkDuplicateKey(flag.key, flag.project_id);
+      if (isDuplicate) {
+         const response: IResponse<IFlag> = {
+            status: 400,
+            message: 'Flag key already exists',
+            data: flag,
+         };
+         res.status(400).json(response);
+         return;
+      }
+
+      const createdFlag = await createFlag(flag);
+      const response: IResponse<IFlag> = {
+         status: 201,
+         message: 'Flag created successfully',
+         data: createdFlag,
+      };
+      res.status(201).json(response);
+   } catch (error: unknown) {
+      if (error instanceof Error) {
+         res.status(500).json({ error: error.message });
+      } else {
+         res.status(500).json({ error: 'An unknown error occurred' });
+      }
+   }
+};
diff --git a/src/middlewares/flags.ts b/src/middlewares/flags.ts
new file mode 100644
index 0000000..bf224f6
--- /dev/null
+++ b/src/middlewares/flags.ts
@@ -0,0 +1,119 @@
+import Joi from 'joi';
+import { NextFunction, Request, Response } from 'express';
+
+const errorMessages = {
+   name: {
+      'string.empty': 'Flag name cannot be empty',
+      'any.required': 'Flag name is required',
+   },
+   description: {
+      'string.empty': 'Description cannot be empty if provided',
+   },
+   key: {
+      'string.empty': 'Flag key cannot be empty',
+      'any.required': 'Flag key is required',
+   },
+   project_id: {
+      'string.empty': 'Project ID cannot be empty',
+      'any.required': 'Project ID is required',
+   },
+   environment_id: {
+      'string.empty': 'Environment ID cannot be empty',
+      'any.required': 'Environment ID is required',
+   },
+   is_active: {
+      'boolean.base': 'Is active must be a boolean value',
+      'any.required': 'Is active status is required',
+   },
+   expires_at: {
+      'date.base': 'Expiration date must be a valid date',
+      'date.greater': 'Expiration date must be in the future',
+   },
+   added_by: {
+      'string.empty': 'Added by cannot be empty',
+      'any.required': 'Added by is required',
+   },
+};
+
+export const createFlagValidator = Joi.object({
+   name: Joi.string()
+      .trim()
+      .min(3)
+      .max(100)
+      .required()
+      .messages(errorMessages.name),
+
+   description: Joi.string()
+      .trim()
+      .max(500)
+      .allow('')
+      .optional()
+      .messages(errorMessages.description),
+
+   key: Joi.string()
+      .trim()
+      .pattern(/^[a-zA-Z0-9_-]+$/)
+      .min(3)
+      .max(50)
+      .required()
+      .messages({
+         ...errorMessages.key,
+         'string.pattern.base':
+            'Flag key must contain only letters, numbers, hyphens and underscores',
+      }),
+
+   project_id: Joi.string()
+      .trim()
+      .uuid()
+      .required()
+      .messages({
+         ...errorMessages.project_id,
+         'string.guid': 'Project ID must be a valid UUID',
+      }),
+
+   environment_id: Joi.string()
+      .trim()
+      .uuid()
+      .required()
+      .messages({
+         ...errorMessages.environment_id,
+         'string.guid': 'Environment ID must be a valid UUID',
+      }),
+
+   is_active: Joi.boolean().required().messages(errorMessages.is_active),
+
+   expires_at: Joi.date()
+      .greater('now')
+      .allow(null)
+      .optional()
+      .messages({
+         ...errorMessages.expires_at,
+         'date.greater': 'Expiration date must be in the future',
+      }),
+
+   added_by: Joi.string()
+      .trim()
+      .uuid()
+      .required()
+      .messages({
+         ...errorMessages.added_by,
+         'string.guid': 'Added by must be a valid UUID',
+      }),
+});
+
+export const validateCreateFlag = async (
+   req: Request,
+   res: Response,
+   next: NextFunction,
+) => {
+   try {
+      await createFlagValidator.validateAsync(req.body);
+      next();
+   } catch (error: unknown) {
+      if (error instanceof Error) {
+         res.status(400).json({ error: error.message });
+      } else {
+         res.status(400).json({ error: 'An unknown error occurred' });
+      }
+   }
+};
diff --git a/src/models/flags.ts b/src/models/flags.ts
index 1761eee..090dd9b 100644
--- a/src/models/flags.ts
+++ b/src/models/flags.ts
@@ -19,3 +19,44 @@ export const getAllFlags = async (): Promise<IFlag[]> => {
       added_by: flag.added_by,
    }));
 };
+
+export const createFlag = async (flag: IFlag): Promise<IFlag> => {
+   const createdFlag = await prisma.flag.create({
+      data: {
+         name: flag.name,
+         description: flag.description,
+         key: flag.key,
+         project_id: flag.project_id,
+         environment_id: flag.environment_id,
+         is_active: flag.is_active,
+         expires_at: flag.expires_at,
+         added_by: flag.added_by,
+      },
+   });
+   return {
+      id: createdFlag.id,
+      name: createdFlag.name,
+      description: createdFlag.description,
+      key: createdFlag.key,
+      project_id: createdFlag.project_id,
+      environment_id: createdFlag.environment_id,
+      is_active: createdFlag.is_active,
+      expires_at: createdFlag.expires_at,
+      created_at: createdFlag.created_at.toISOString(),
+      updated_at: createdFlag.updated_at.toISOString(),
+      added_by: createdFlag.added_by,
+   };
+};
+
+export const checkDuplicateKey = async (
+   key: string,
+   project_id: string,
+): Promise<boolean> => {
+   const flag = await prisma.flag.findFirst({
+      where: {
+         key,
+         project_id,
+      },
+   });
+   return flag !== null;
+};
diff --git a/src/routes/flags.ts b/src/routes/flags.ts
index 91d90ff..c6e5b3f 100644
--- a/src/routes/flags.ts
+++ b/src/routes/flags.ts
@@ -1,6 +1,8 @@
-import { getFlagsController } from '../controllers/flags';
+import { getFlagsController, createFlagController } from '../controllers/flags';
 import express from 'express';
+import { validateCreateFlag } from '../middlewares/flags';
 
 export default (router: express.Router) => {
    router.get('/flags', getFlagsController);
+   router.post('/flags', validateCreateFlag, createFlagController);
 };