diff --git a/package.json b/package.json
index 2719f795e..a67f46afa 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "iSunFA",
-  "version": "0.8.0+20",
+  "version": "0.8.0+22",
   "private": false,
   "scripts": {
     "dev": "next dev",
diff --git a/prisma/seed_json/employee_project.json b/prisma/seed_json/employee_project.json
index 8b05bcdb2..a072e6da9 100644
--- a/prisma/seed_json/employee_project.json
+++ b/prisma/seed_json/employee_project.json
@@ -13,7 +13,7 @@
         "employeeId": 1001,
         "projectId": 1000,
         "startDate": 1635724800,
-        "endDate": 1635811200,
+        "endDate": null,
         "createdAt": 1635724800,
         "updatedAt": 1635724800
     }
diff --git a/prisma/seed_json/milestone.json b/prisma/seed_json/milestone.json
index 2966d86ba..49cdddb4a 100644
--- a/prisma/seed_json/milestone.json
+++ b/prisma/seed_json/milestone.json
@@ -1,6 +1,6 @@
 [
   {
-    "id":1015,
+    "id": 1015,
     "projectId": 1001,
     "startDate": 1709578219,
     "endDate": 1712256619,
@@ -81,7 +81,7 @@
     "updatedAt": 1717637165
   },
   {
-    "id":1014,
+    "id": 1014,
     "projectId": 1007,
     "startDate": 1717637165,
     "endDate": 1718179676,
@@ -142,5 +142,59 @@
     "status": "Archived",
     "createdAt": 1709578219,
     "updatedAt": 1709578219
+  },
+  {
+    "id": 1016,
+    "projectId": 1009,
+    "startDate": 0,
+    "endDate": 0,
+    "status": "Designing",
+    "createdAt": 1709578219,
+    "updatedAt": 1709578219
+  },
+  {
+    "id": 1017,
+    "projectId": 1009,
+    "startDate": 0,
+    "endDate": 0,
+    "status": "Beta Testing",
+    "createdAt": 1709578219,
+    "updatedAt": 1709578219
+  },
+  {
+    "id": 1018,
+    "projectId": 1009,
+    "startDate": 0,
+    "endDate": 0,
+    "status": "Develop",
+    "createdAt": 1709578219,
+    "updatedAt": 1709578219
+  },
+  {
+    "id": 1019,
+    "projectId": 1009,
+    "startDate": 0,
+    "endDate": 0,
+    "status": "Selling",
+    "createdAt": 1709578219,
+    "updatedAt": 1709578219
+  },
+  {
+    "id": 1020,
+    "projectId": 1009,
+    "startDate": 0,
+    "endDate": 0,
+    "status": "Sold",
+    "createdAt": 1709578219,
+    "updatedAt": 1709578219
+  },
+  {
+    "id": 1021,
+    "projectId": 1009,
+    "startDate": 0,
+    "endDate": 0,
+    "status": "Archived",
+    "createdAt": 1709578219,
+    "updatedAt": 1709578219
   }
-]
\ No newline at end of file
+]
diff --git a/prisma/seed_json/project.json b/prisma/seed_json/project.json
index 6aba557b1..e504038fa 100644
--- a/prisma/seed_json/project.json
+++ b/prisma/seed_json/project.json
@@ -97,5 +97,16 @@
     "createdAt": 1651368365,
     "updatedAt": 1651368365,
     "deletedAt": null
+  },
+  {
+    "id": 1009,
+    "companyId": 1000,
+    "name": "Test update Project",
+    "completedPercent": 83,
+    "stage": "Beta Testing",
+    "imageId": "TP",
+    "createdAt": 1651368365,
+    "updatedAt": 1651368365,
+    "deletedAt": null
   }
 ]
diff --git a/src/lib/utils/repo/authentication.repo.ts b/src/lib/utils/repo/authentication.repo.ts
index d35feffdf..493e9c112 100644
--- a/src/lib/utils/repo/authentication.repo.ts
+++ b/src/lib/utils/repo/authentication.repo.ts
@@ -4,8 +4,8 @@ import { timestampInSeconds } from '@/lib/utils/common';
 
 export async function getUserByCredential(
   credentialId: string
-): Promise<(Authentication & { user: User }) | null> {
-  let user: (Authentication & { user: User }) | null = null;
+): Promise<(Authentication & { user: User & { userAgreements: UserAgreement[] } }) | null> {
+  let user: (Authentication & { user: User & { userAgreements: UserAgreement[] } }) | null = null;
   if (credentialId.trim() !== '') {
     user = await prisma.authentication.findUnique({
       where: {
@@ -13,7 +13,11 @@ export async function getUserByCredential(
         OR: [{ deletedAt: 0 }, { deletedAt: null }],
       },
       include: {
-        user: true,
+        user: {
+          include: {
+            userAgreements: true,
+          },
+        },
       },
     });
   }
diff --git a/src/lib/utils/repo/employee.repo.ts b/src/lib/utils/repo/employee.repo.ts
index f27426ed1..06fbad3aa 100644
--- a/src/lib/utils/repo/employee.repo.ts
+++ b/src/lib/utils/repo/employee.repo.ts
@@ -238,13 +238,11 @@ export async function getProjectsByEmployeeId(employeeIdNumber: number) {
       employeeId: employeeIdNumber,
       endDate: null,
     },
-    select: {
-      project: {
-        select: {
-          id: true,
-          name: true,
-        },
-      },
+    include: {
+      project: true,
+    },
+    orderBy: {
+      startDate: 'asc',
     },
   });
   return projects;
diff --git a/src/lib/utils/repo/profit_comparison.repo.ts b/src/lib/utils/repo/profit_comparison.repo.ts
index 51d5827ea..cbad8b5bf 100644
--- a/src/lib/utils/repo/profit_comparison.repo.ts
+++ b/src/lib/utils/repo/profit_comparison.repo.ts
@@ -9,6 +9,9 @@ export async function getProjectLists(companyId: number) {
     where: {
       companyId,
     },
+    orderBy: {
+      name: 'asc',
+    },
   });
 }
 
diff --git a/src/lib/utils/repo_test/employee.repo.test.ts b/src/lib/utils/repo_test/employee.repo.test.ts
index 0ca2b95b8..2fa03c55b 100644
--- a/src/lib/utils/repo_test/employee.repo.test.ts
+++ b/src/lib/utils/repo_test/employee.repo.test.ts
@@ -75,11 +75,10 @@ describe('Employee Repository Tests', () => {
   });
   describe('getProjectsByEmployeeId', () => {
     it('should get projects by employee id', async () => {
-      const employeeId = 1000;
+      const employeeId = 1001;
       const projectsFromDb = await getProjectsByEmployeeId(employeeId);
       expect(projectsFromDb).toBeDefined();
       expect(Array.isArray(projectsFromDb)).toBe(true);
-      expect(projectsFromDb.length).toBeGreaterThan(0);
       expect(projectsFromDb[0].project.id).toEqual(employeeProjects[0].projectId);
     });
   });
diff --git a/src/lib/utils/repo_test/trasaction_test/project_members.tx.test.ts b/src/lib/utils/repo_test/trasaction_test/project_members.tx.test.ts
index d1433ac25..baeaa16a5 100644
--- a/src/lib/utils/repo_test/trasaction_test/project_members.tx.test.ts
+++ b/src/lib/utils/repo_test/trasaction_test/project_members.tx.test.ts
@@ -45,6 +45,18 @@ describe('ProjectMembers Transaction Tests', () => {
       });
       expect(existingMembers.length).toBe(2);
       await updateProjectMembers(testProjectId, memberIdList); // Reset the members
+      await prisma.employeeProject.deleteMany({
+        where: {
+          projectId: testProjectId,
+          employeeId: {
+            in: [1000, 1001, 1002],
+          },
+          endDate: { not: null },
+          id: {
+            gte: 10000000,
+          },
+        },
+      });
     }, 10000);
   });
 });
diff --git a/src/lib/utils/repo_test/trasaction_test/project_milestone.tx.test.ts b/src/lib/utils/repo_test/trasaction_test/project_milestone.tx.test.ts
index 3375a2a52..693dd4cf2 100644
--- a/src/lib/utils/repo_test/trasaction_test/project_milestone.tx.test.ts
+++ b/src/lib/utils/repo_test/trasaction_test/project_milestone.tx.test.ts
@@ -10,7 +10,7 @@ import { formatMilestoneList } from '@/lib/utils/formatter/milestone.formatter';
 import { IMilestone } from '@/interfaces/project';
 
 let milestoneList: IMilestone[] = [];
-const testProjectId = 1000;
+const testProjectId = 1009;
 
 beforeAll(async () => {
   const listedMilestone = await listProjectMilestone(testProjectId);
@@ -18,8 +18,8 @@ beforeAll(async () => {
 });
 
 describe('Project Milestone Tests', () => {
-  const defaultStage = 'Beta Testing';
-  const updateStage = 'Sold';
+  const defaultStage = 'Develop';
+  const updateStage = 'Selling';
   const now = Date.now();
   const nowTimestamp = timestampInSeconds(now);
 
diff --git a/src/pages/api/v1/company/[companyId]/account/[accountId]/index.ts b/src/pages/api/v1/company/[companyId]/account/[accountId]/index.ts
index 3fde7cd51..00c5be676 100644
--- a/src/pages/api/v1/company/[companyId]/account/[accountId]/index.ts
+++ b/src/pages/api/v1/company/[companyId]/account/[accountId]/index.ts
@@ -14,7 +14,6 @@ import { getSession } from '@/lib/utils/session';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 
 function formatParams(companyId: unknown, accountId: string | string[] | undefined) {
-  // ToDo: (20240613 - Murky) - need to use type guard instead
   const isCompanyIdValid = !Number.isNaN(Number(companyId));
   const isAccountIdValid = isParamNumeric(accountId);
 
@@ -33,6 +32,9 @@ function formatParams(companyId: unknown, accountId: string | string[] | undefin
 async function getCompanyIdAccountId(req: NextApiRequest, res: NextApiResponse) {
   const session = await getSession(req, res);
   const { userId, companyId } = session;
+  if (!userId) {
+    throw new Error(STATUS_MESSAGE.UNAUTHORIZED_ACCESS);
+  }
   const isAuth = await checkAuthorization([AuthFunctionsKeys.admin], { userId, companyId });
   if (!isAuth) {
     throw new Error(STATUS_MESSAGE.FORBIDDEN);
@@ -45,69 +47,86 @@ async function getCompanyIdAccountId(req: NextApiRequest, res: NextApiResponse)
   };
 }
 
-export async function handleGetRequest(companyIdNumber: number, accountIdNumber: number) {
+async function handleGetRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAccount | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAccount | null = null;
+
+  const { companyIdNumber, accountIdNumber } = await getCompanyIdAccountId(req, res);
   const accountFromDb = await findFirstAccountInPrisma(accountIdNumber, companyIdNumber);
   const account = accountFromDb ? formatAccount(accountFromDb) : ({} as IAccount);
-  const { httpCode, result } = formatApiResponse<IAccount>(STATUS_MESSAGE.SUCCESS, account);
-  return {
-    httpCode,
-    result,
-  };
+  statusMessage = STATUS_MESSAGE.SUCCESS;
+  payload = account;
+
+  return { statusMessage, payload };
 }
 
-async function handlePutRequest(companyIdNumber: number, accountIdNumber: number, name: string) {
+async function handlePutRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAccount | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAccount | null = null;
+
+  const { companyIdNumber, accountIdNumber } = await getCompanyIdAccountId(req, res);
+  const { name } = req.body;
   const updatedAccount = await updateAccountInPrisma(accountIdNumber, companyIdNumber, name);
   const account = updatedAccount ? formatAccount(updatedAccount) : ({} as IAccount);
-  const { httpCode, result } = formatApiResponse<IAccount>(STATUS_MESSAGE.SUCCESS_UPDATE, account);
-  return {
-    httpCode,
-    result,
-  };
+  statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
+  payload = account;
+
+  return { statusMessage, payload };
 }
 
-async function handleDeleteRequest(companyIdNumber: number, accountIdNumber: number) {
+async function handleDeleteRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAccount | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAccount | null = null;
+
+  const { companyIdNumber, accountIdNumber } = await getCompanyIdAccountId(req, res);
   const deletedAccount = await softDeleteAccountInPrisma(accountIdNumber, companyIdNumber);
   const account = deletedAccount ? formatAccount(deletedAccount) : ({} as IAccount);
-  const { httpCode, result } = formatApiResponse<IAccount>(STATUS_MESSAGE.SUCCESS_DELETE, account);
-  return {
-    httpCode,
-    result,
-  };
-}
+  statusMessage = STATUS_MESSAGE.SUCCESS_DELETE;
+  payload = account;
 
-export function handleErrorResponse(res: NextApiResponse, message: string) {
-  const { httpCode, result } = formatApiResponse<IAccount>(message, {} as IAccount);
-  return {
-    httpCode,
-    result,
-  };
+  return { statusMessage, payload };
 }
 
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: IAccount | null }>;
+} = {
+  GET: handleGetRequest,
+  PUT: handlePutRequest,
+  DELETE: handleDeleteRequest,
+};
+
 export default async function handler(
   req: NextApiRequest,
-  res: NextApiResponse<IResponseData<IAccount>>
+  res: NextApiResponse<IResponseData<IAccount | null>>
 ) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAccount | null = null;
+
   try {
-    const { companyIdNumber, accountIdNumber } = await getCompanyIdAccountId(req, res);
-    if (req.method === 'GET') {
-      const { httpCode, result } = await handleGetRequest(companyIdNumber, accountIdNumber);
-      res.status(httpCode).json(result);
-    } else if (req.method === 'PUT') {
-      const { name } = req.body;
-      const { httpCode, result } = await handlePutRequest(companyIdNumber, accountIdNumber, name);
-      res.status(httpCode).json(result);
-    } else if (req.method === 'DELETE') {
-      const { httpCode, result } = await handleDeleteRequest(companyIdNumber, accountIdNumber);
-      res.status(httpCode).json(result);
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
     } else {
-      throw new Error(STATUS_MESSAGE.METHOD_NOT_ALLOWED);
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
-    // Info Murky (20240416): Debugging
-    // eslint-disable-next-line no-console
-    console.error(error.message);
-    const { httpCode, result } = handleErrorResponse(res, error.message);
+    statusMessage = error.message;
+    payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<IAccount | null>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }
diff --git a/src/pages/api/v1/company/[companyId]/account/index.ts b/src/pages/api/v1/company/[companyId]/account/index.ts
index c02e0c230..338a05148 100644
--- a/src/pages/api/v1/company/[companyId]/account/index.ts
+++ b/src/pages/api/v1/company/[companyId]/account/index.ts
@@ -173,7 +173,7 @@ export function formatGetQuery(companyId: number, req: NextApiRequest): IAccount
     sortBy: formattedSortBy,
     sortOrder: formattedSortOrder,
     searchKey: formattedSearchKey,
-    isDeleted: formattedIsDeleted
+    isDeleted: formattedIsDeleted,
   };
 }
 
@@ -220,6 +220,9 @@ export async function handlePostRequest(
   const session = await getSession(req, res);
   const { userId, companyId } = session;
   const { accountId, name } = req.body;
+  if (!userId) {
+    throw new Error(STATUS_MESSAGE.UNAUTHORIZED_ACCESS);
+  }
   const isAuth = await checkAuthorization([AuthFunctionsKeys.admin], { userId, companyId });
   if (!isAuth) {
     throw new Error(STATUS_MESSAGE.FORBIDDEN);
@@ -233,7 +236,7 @@ export async function handlePostRequest(
   }
   const latestSubAccount = await findLatestSubAccountInPrisma(parentAccount);
   const newCode = setNewCode(parentAccount, latestSubAccount);
-  const newName = parentAccount.name + "-" + String(name);
+  const newName = parentAccount.name + '-' + String(name);
   const newOwnAccount = {
     companyId: companyIdNumber,
     system: parentAccount.system,
diff --git a/src/pages/api/v1/company/[companyId]/admin/[adminId]/index.ts b/src/pages/api/v1/company/[companyId]/admin/[adminId]/index.ts
index de5a224ab..4eb5f8026 100644
--- a/src/pages/api/v1/company/[companyId]/admin/[adminId]/index.ts
+++ b/src/pages/api/v1/company/[companyId]/admin/[adminId]/index.ts
@@ -1,77 +1,154 @@
 import { STATUS_MESSAGE } from '@/constants/status_code';
 import { IResponseData } from '@/interfaces/response_data';
+import { IAdmin } from '@/interfaces/admin';
 import { convertStringToNumber, formatApiResponse } from '@/lib/utils/common';
 import { NextApiRequest, NextApiResponse } from 'next';
-import { IAdmin } from '@/interfaces/admin';
 import { checkAuthorization } from '@/lib/utils/auth_check';
 import { deleteAdminById, getAdminById, updateAdminById } from '@/lib/utils/repo/admin.repo';
 import { formatAdmin } from '@/lib/utils/formatter/admin.formatter';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 import { getSession } from '@/lib/utils/session';
 
-export default async function handler(
+async function handleGetRequest(
   req: NextApiRequest,
-  res: NextApiResponse<IResponseData<IAdmin | IAdmin[]>>
+  res: NextApiResponse<IResponseData<IAdmin | null>>
 ) {
-  try {
-    const { adminId } = req.query;
-    const adminIdNum = convertStringToNumber(adminId);
-    if (req.method === 'GET') {
-      const session = await getSession(req, res);
-      const { userId, companyId } = session;
-      const isAuth = await checkAuthorization(
-        [AuthFunctionsKeys.CompanyAdminMatch, AuthFunctionsKeys.admin],
-        { userId, companyId, adminId: adminIdNum }
-      );
-      if (!isAuth) {
-        throw new Error(STATUS_MESSAGE.FORBIDDEN);
-      }
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAdmin | null = null;
+
+  const { adminId } = req.query;
+  const adminIdNum = convertStringToNumber(adminId);
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+  } else {
+    const isAuth = await checkAuthorization(
+      [AuthFunctionsKeys.CompanyAdminMatch, AuthFunctionsKeys.admin],
+      { userId, companyId, adminId: adminIdNum }
+    );
+
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
       const getAdmin = await getAdminById(adminIdNum);
       if (!getAdmin) {
-        throw new Error(STATUS_MESSAGE.RESOURCE_NOT_FOUND);
-      }
-      const admin = await formatAdmin(getAdmin);
-      const { httpCode, result } = formatApiResponse<IAdmin>(STATUS_MESSAGE.SUCCESS_GET, admin);
-      res.status(httpCode).json(result);
-      // Info: (20240419 - Jacky) S010003 - PUT /subscription/:id
-    } else if (req.method === 'PUT') {
-      const { status, roleName } = req.body;
-      if (typeof status !== 'boolean' && !roleName) {
-        throw new Error(STATUS_MESSAGE.INVALID_INPUT_PARAMETER);
+        statusMessage = STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+      } else {
+        const admin = await formatAdmin(getAdmin);
+        statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+        payload = admin;
       }
-      const session = await getSession(req, res);
-      const { userId, companyId } = session;
-      const isAuth = await checkAuthorization(
-        [AuthFunctionsKeys.owner, AuthFunctionsKeys.CompanyAdminMatch],
-        { userId, companyId, adminId: adminIdNum }
-      );
-      if (!isAuth) {
-        throw new Error(STATUS_MESSAGE.FORBIDDEN);
-      }
-      const updatedAdmin = await updateAdminById(adminIdNum, status, roleName);
-      const admin = await formatAdmin(updatedAdmin);
-      const { httpCode, result } = formatApiResponse<IAdmin>(STATUS_MESSAGE.SUCCESS_UPDATE, admin);
-      res.status(httpCode).json(result);
-    } else if (req.method === 'DELETE') {
-      const session = await getSession(req, res);
-      const { userId, companyId } = session;
+    }
+  }
+
+  return { statusMessage, payload };
+}
+
+async function handlePutRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAdmin | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAdmin | null = null;
+
+  const { adminId } = req.query;
+  const adminIdNum = convertStringToNumber(adminId);
+  const { status, roleName } = req.body;
+
+  if (typeof status !== 'boolean' && !roleName) {
+    statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
+  } else {
+    const session = await getSession(req, res);
+    const { userId, companyId } = session;
+
+    if (!userId) {
+      statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+    } else {
       const isAuth = await checkAuthorization(
         [AuthFunctionsKeys.owner, AuthFunctionsKeys.CompanyAdminMatch],
         { userId, companyId, adminId: adminIdNum }
       );
+
       if (!isAuth) {
-        throw new Error(STATUS_MESSAGE.FORBIDDEN);
+        statusMessage = STATUS_MESSAGE.FORBIDDEN;
+      } else {
+        const updatedAdmin = await updateAdminById(adminIdNum, status, roleName);
+        const admin = await formatAdmin(updatedAdmin);
+        statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
+        payload = admin;
       }
+    }
+  }
+
+  return { statusMessage, payload };
+}
+
+async function handleDeleteRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAdmin | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAdmin | null = null;
+
+  const { adminId } = req.query;
+  const adminIdNum = convertStringToNumber(adminId);
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+  } else {
+    const isAuth = await checkAuthorization(
+      [AuthFunctionsKeys.owner, AuthFunctionsKeys.CompanyAdminMatch],
+      { userId, companyId, adminId: adminIdNum }
+    );
+
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
       const deletedAdmin = await deleteAdminById(adminIdNum);
       const admin = await formatAdmin(deletedAdmin);
-      const { httpCode, result } = formatApiResponse<IAdmin>(STATUS_MESSAGE.SUCCESS_DELETE, admin);
-      res.status(httpCode).json(result);
+      statusMessage = STATUS_MESSAGE.SUCCESS_DELETE;
+      payload = admin;
+    }
+  }
+
+  return { statusMessage, payload };
+}
+
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: IAdmin | null }>;
+} = {
+  GET: handleGetRequest,
+  PUT: handlePutRequest,
+  DELETE: handleDeleteRequest,
+};
+
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAdmin | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAdmin | null = null;
+
+  try {
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
     } else {
-      throw new Error(STATUS_MESSAGE.METHOD_NOT_ALLOWED);
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
-    const { httpCode, result } = formatApiResponse<IAdmin>(error.message, {} as IAdmin);
+    statusMessage = error.message;
+    payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<IAdmin | null>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }
diff --git a/src/pages/api/v1/company/[companyId]/admin/index.ts b/src/pages/api/v1/company/[companyId]/admin/index.ts
index 1a259f72e..2310347d8 100644
--- a/src/pages/api/v1/company/[companyId]/admin/index.ts
+++ b/src/pages/api/v1/company/[companyId]/admin/index.ts
@@ -1,39 +1,71 @@
 import { STATUS_MESSAGE } from '@/constants/status_code';
 import { IResponseData } from '@/interfaces/response_data';
+import { IAdmin } from '@/interfaces/admin';
 import { formatApiResponse } from '@/lib/utils/common';
 import { NextApiRequest, NextApiResponse } from 'next';
-import { IAdmin } from '@/interfaces/admin';
 import { checkAuthorization } from '@/lib/utils/auth_check';
 import { listAdminByCompanyId } from '@/lib/utils/repo/admin.repo';
 import { formatAdminList } from '@/lib/utils/formatter/admin.formatter';
 import { getSession } from '@/lib/utils/session';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 
-export default async function handler(
+async function handleGetRequest(
   req: NextApiRequest,
-  res: NextApiResponse<IResponseData<IAdmin | IAdmin[]>>
+  res: NextApiResponse<IResponseData<IAdmin[]>>
 ) {
-  try {
-    if (req.method === 'GET') {
-      const session = await getSession(req, res);
-      const { userId, companyId } = session;
-      const isAuth = await checkAuthorization([AuthFunctionsKeys.admin], { userId, companyId });
-      if (!isAuth) {
-        throw new Error(STATUS_MESSAGE.FORBIDDEN);
-      }
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAdmin[] = [];
+
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+  } else {
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.admin], { userId, companyId });
+
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
       const listedAdmin = await listAdminByCompanyId(companyId);
       const adminList = await formatAdminList(listedAdmin);
-      const { httpCode, result } = formatApiResponse<IAdmin[]>(
-        STATUS_MESSAGE.SUCCESS_GET,
-        adminList
-      );
-      res.status(httpCode).json(result);
+      statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+      payload = adminList;
+    }
+  }
+
+  return { statusMessage, payload };
+}
+
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: IAdmin[] }>;
+} = {
+  GET: handleGetRequest,
+};
+
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAdmin[]>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IAdmin[] = [];
+
+  try {
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
     } else {
-      throw new Error(STATUS_MESSAGE.METHOD_NOT_ALLOWED);
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
-    const { httpCode, result } = formatApiResponse<IAdmin>(error.message, {} as IAdmin);
+    statusMessage = error.message;
+    payload = [];
+  } finally {
+    const { httpCode, result } = formatApiResponse<IAdmin[]>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }
diff --git a/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/index.ts b/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/index.ts
index 2b222f2eb..9cd548b3d 100644
--- a/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/index.ts
+++ b/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/index.ts
@@ -1,19 +1,18 @@
-import { AICH_URI } from '@/constants/config';
+import { STATUS_MESSAGE } from '@/constants/status_code';
 import { IResponseData } from '@/interfaces/response_data';
 import { IVoucherDataForSavingToDB } from '@/interfaces/voucher';
 import { NextApiRequest, NextApiResponse } from 'next';
-import { STATUS_MESSAGE } from '@/constants/status_code';
 import { formatApiResponse, isParamString } from '@/lib/utils/common';
 import { ILineItem, ILineItemFromAICH } from '@/interfaces/line_item';
 import { fuzzySearchAccountByName } from '@/pages/api/v1/company/[companyId]/ask_ai/[resultId]/index.repository';
 import { isILineItem } from '@/lib/utils/type_guard/line_item';
 import { isIVoucherDataForSavingToDB } from '@/lib/utils/type_guard/voucher';
 import { IContract } from '@/interfaces/contract';
+import { AICH_URI } from '@/constants/config';
 
 type ApiResponseType = IVoucherDataForSavingToDB | IContract | null;
-// Info: （ 20240522 - Murkky）目前只可以使用Voucher Return
 
-export async function fetchResultFromAICH(aiApi: string, resultId: string) {
+async function fetchResultFromAICH(aiApi: string, resultId: string) {
   let response: Response;
   try {
     response = await fetch(`${AICH_URI}/api/v1/${aiApi}/${resultId}/result`);
@@ -23,17 +22,13 @@ export async function fetchResultFromAICH(aiApi: string, resultId: string) {
   if (response.status === 404) {
     throw new Error(STATUS_MESSAGE.AICH_API_NOT_FOUND);
   }
-
   if (!response.ok) {
     throw new Error(STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_AICH_FAILED);
   }
-
   return response.json() as Promise<{ payload?: unknown } | null>;
 }
 
-export async function getPayloadFromResponseJSON(
-  responseJSON: Promise<{ payload?: unknown } | null>
-) {
+async function getPayloadFromResponseJSON(responseJSON: Promise<{ payload?: unknown } | null>) {
   if (!responseJSON) {
     throw new Error(STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_AICH_FAILED);
   }
@@ -45,9 +40,6 @@ export async function getPayloadFromResponseJSON(
   try {
     json = await responseJSON;
   } catch (error) {
-    // Deprecated: （ 20240522 - Murky）Debugging purpose
-    // eslint-disable-next-line no-console
-    console.error(error);
     throw new Error(STATUS_MESSAGE.PARSE_JSON_FAILED_ERROR);
   }
 
@@ -65,9 +57,7 @@ async function formatLineItemsFromAICH(rawLineItems: ILineItemFromAICH[]) {
       const accountInDB = await fuzzySearchAccountByName(account);
 
       if (!accountInDB) {
-        // Deprecated: （ 20240522 - Murkky）Debugging purpose
-        // eslint-disable-next-line no-console
-        console.log(`Account ${account} not found in database`);
+        throw new Error(STATUS_MESSAGE.RESOURCE_NOT_FOUND);
       }
 
       const resultAccount = {
@@ -80,9 +70,6 @@ async function formatLineItemsFromAICH(rawLineItems: ILineItemFromAICH[]) {
       } as ILineItem;
 
       if (!isILineItem(resultAccount)) {
-        // Deprecated: （ 20240522 - Murky）Debugging purpose
-        // eslint-disable-next-line no-console
-        console.log(`LineItem ${account} is not valid`);
         throw new Error(STATUS_MESSAGE.INTERNAL_SERVICE_ERROR);
       }
       return resultAccount;
@@ -91,72 +78,76 @@ async function formatLineItemsFromAICH(rawLineItems: ILineItemFromAICH[]) {
   return lineItems;
 }
 
-export async function handleGetRequest(req: NextApiRequest) {
+async function handleGetRequest(req: NextApiRequest) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
   let payload: IVoucherDataForSavingToDB | IContract | null = null;
   const { resultId, aiApi = 'vouchers' } = req.query;
-  // Info Murky (20240416): Check if resultId is string
-  if (!isParamString(resultId) || !isParamString(aiApi)) {
-    throw new Error(STATUS_MESSAGE.INVALID_INPUT_PARAMETER);
-  }
 
-  const fetchResult = fetchResultFromAICH(aiApi, resultId);
-
-  switch (aiApi) {
-    case 'vouchers': {
-      const { lineItems: rawLineItems } = (await getPayloadFromResponseJSON(fetchResult)) as {
-        lineItems: ILineItemFromAICH[];
-      };
-
-      const lineItems = await formatLineItemsFromAICH(rawLineItems);
-      const voucher = {
-        lineItems,
-      } as IVoucherDataForSavingToDB;
-      if (!isIVoucherDataForSavingToDB(voucher)) {
-        // Deprecated: （ 20240522 - Murky）Debugging purpose
-        // eslint-disable-next-line no-console
-        console.log('Voucher is not valid');
-        throw new Error(STATUS_MESSAGE.INTERNAL_SERVICE_ERROR);
+  if (!isParamString(resultId) || !isParamString(aiApi)) {
+    statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
+  } else {
+    const fetchResult = fetchResultFromAICH(aiApi, resultId);
+
+    switch (aiApi) {
+      case 'vouchers': {
+        const { lineItems: rawLineItems } = (await getPayloadFromResponseJSON(fetchResult)) as {
+          lineItems: ILineItemFromAICH[];
+        };
+
+        const lineItems = await formatLineItemsFromAICH(rawLineItems);
+        const voucher = {
+          lineItems,
+        } as IVoucherDataForSavingToDB;
+        if (!isIVoucherDataForSavingToDB(voucher)) {
+          statusMessage = STATUS_MESSAGE.INTERNAL_SERVICE_ERROR;
+        } else {
+          statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+          payload = voucher;
+        }
+        break;
       }
-      payload = voucher;
-      break;
-    }
-    case 'contracts': {
-      // Todo (20240625 - Jacky): Implement contract return
-      payload = (await fetchResult) as IContract;
-      break;
+      case 'contracts': {
+        payload = (await fetchResult) as IContract;
+        statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+        break;
+      }
+      default:
+        statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
     }
-    default:
-      throw new Error(STATUS_MESSAGE.INVALID_INPUT_PARAMETER);
   }
 
-  const { httpCode, result } = formatApiResponse<ApiResponseType>(
-    STATUS_MESSAGE.SUCCESS_GET,
-    payload
-  );
-
-  return { httpCode, result };
+  return { statusMessage, payload };
 }
 
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: ApiResponseType }>;
+} = {
+  GET: handleGetRequest,
+};
+
 export default async function handler(
   req: NextApiRequest,
   res: NextApiResponse<IResponseData<ApiResponseType>>
 ) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: ApiResponseType = null;
+
   try {
-    if (req.method === 'GET') {
-      const { httpCode, result } = await handleGetRequest(req);
-      res.status(httpCode).json(result);
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
     } else {
-      throw new Error(STATUS_MESSAGE.METHOD_NOT_ALLOWED);
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
-    // Deprecated: （ 20240522 - Murky）Debugging purpose
-    // eslint-disable-next-line no-console
-    console.error(error);
-    const { httpCode, result } = formatApiResponse<ApiResponseType>(
-      error.message,
-      {} as ApiResponseType
-    );
+    statusMessage = error.message;
+    payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<ApiResponseType>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }
diff --git a/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/status.ts b/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/status.ts
index 04914a81e..4d8088d9b 100644
--- a/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/status.ts
+++ b/src/pages/api/v1/company/[companyId]/ask_ai/[resultId]/status.ts
@@ -1,58 +1,73 @@
-import type { NextApiRequest, NextApiResponse } from 'next';
-import { AICH_URI } from '@/constants/config';
-import { IResponseData } from '@/interfaces/response_data';
-import { formatApiResponse } from '@/lib/utils/common';
 import { STATUS_MESSAGE } from '@/constants/status_code';
+import { IResponseData } from '@/interfaces/response_data';
 import { ProgressStatus } from '@/constants/account';
+import { formatApiResponse } from '@/lib/utils/common';
+import { NextApiRequest, NextApiResponse } from 'next';
 import { isProgressStatus } from '@/lib/utils/type_guard/account';
+import { AICH_URI } from '@/constants/config';
 
-export default async function handler(
-  req: NextApiRequest,
-  res: NextApiResponse<IResponseData<ProgressStatus>>
-) {
-  try {
-    const { resultId, aiApi = 'vouchers' } = req.query;
+async function handleGetRequest(req: NextApiRequest) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: ProgressStatus | null = null;
+  const { resultId, aiApi = 'vouchers' } = req.query;
 
-    // Info Murky (20240416): Check if resultId is string
-    if (typeof resultId !== 'string' || !resultId || Array.isArray(resultId)) {
-      throw new Error(STATUS_MESSAGE.INVALID_INPUT_PARAMETER);
-    }
+  if (typeof resultId !== 'string' || !resultId || Array.isArray(resultId)) {
+    statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
+  } else {
+    try {
+      const fetchResult = await fetch(`${AICH_URI}/api/v1/${aiApi}/${resultId}/process_status`);
 
-    switch (req.method) {
-      case 'GET': {
-        const fetchResult = await fetch(`${AICH_URI}/api/v1/${aiApi}/${resultId}/process_status`);
+      if (fetchResult.status === 404) {
+        statusMessage = STATUS_MESSAGE.AICH_API_NOT_FOUND;
+      } else if (!fetchResult.ok) {
+        statusMessage = STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_AICH_FAILED;
+      } else {
+        const resultJson: ProgressStatus = (await fetchResult.json()).payload;
 
-        if (fetchResult.status === 404) {
-          throw new Error(STATUS_MESSAGE.AICH_API_NOT_FOUND);
+        if (!resultJson || !isProgressStatus(resultJson)) {
+          statusMessage = STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_DATA_FROM_AICH_IS_INVALID_TYPE;
+        } else {
+          statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+          payload = resultJson;
         }
+      }
+    } catch (error) {
+      statusMessage = STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_AICH_FAILED;
+    }
+  }
 
-        if (!fetchResult.ok) {
-          throw new Error(STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_AICH_FAILED);
-        }
+  return { statusMessage, payload };
+}
 
-        const resultJson: ProgressStatus = (await fetchResult.json()).payload;
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: ProgressStatus | null }>;
+} = {
+  GET: handleGetRequest,
+};
 
-        if (!resultJson || !isProgressStatus(resultJson)) {
-          throw new Error(STATUS_MESSAGE.INTERNAL_SERVICE_ERROR_DATA_FROM_AICH_IS_INVALID_TYPE);
-        }
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<ProgressStatus | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: ProgressStatus | null = null;
 
-        const { httpCode, result } = formatApiResponse<ProgressStatus>(
-          STATUS_MESSAGE.SUCCESS_GET,
-          resultJson
-        );
-        res.status(httpCode).json(result);
-        break;
-      }
-      default: {
-        throw new Error(STATUS_MESSAGE.METHOD_NOT_ALLOWED);
-      }
+  try {
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
+    } else {
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
-    const { httpCode, result } = formatApiResponse<ProgressStatus>(
-      error.message,
-      {} as ProgressStatus
-    );
+    statusMessage = error.message;
+    payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<ProgressStatus | null>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }
diff --git a/src/pages/api/v1/company/[companyId]/index.ts b/src/pages/api/v1/company/[companyId]/index.ts
index 7444b0064..309ee91ac 100644
--- a/src/pages/api/v1/company/[companyId]/index.ts
+++ b/src/pages/api/v1/company/[companyId]/index.ts
@@ -1,94 +1,103 @@
-import { NextApiRequest, NextApiResponse } from 'next';
 import { STATUS_MESSAGE } from '@/constants/status_code';
 import { IResponseData } from '@/interfaces/response_data';
-import { ICompany, ICompanyAndRole } from '@/interfaces/company';
+import { IUser } from '@/interfaces/user';
 import { convertStringToNumber, formatApiResponse } from '@/lib/utils/common';
-import { checkAuthorization } from '@/lib/utils/auth_check';
+import { getUserById, updateUserById } from '@/lib/utils/repo/user.repo';
+import { formatUser } from '@/lib/utils/formatter/user.formatter';
+import { NextApiRequest, NextApiResponse } from 'next';
 import { getSession } from '@/lib/utils/session';
-import {
-  getCompanyById,
-  deleteCompanyById,
-  updateCompanyById,
-} from '@/lib/utils/repo/company.repo';
-import { formatCompany } from '@/lib/utils/formatter/company.formatter';
-import {
-  deleteAdminListByCompanyId,
-  getCompanyDetailAndRoleByCompanyId,
-} from '@/lib/utils/repo/admin.repo';
-import { formatCompanyDetailAndRole } from '@/lib/utils/formatter/admin.formatter';
+import { checkAuthorization } from '@/lib/utils/auth_check';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 
-async function handleGetRequest(req: NextApiRequest, res: NextApiResponse) {
+async function checkInput(
+  userId: string,
+  name: string,
+  fullName: string,
+  email: string,
+  phone: string
+): Promise<boolean> {
+  return !!userId && !!name && !!fullName && !!email && !!phone;
+}
+
+async function handleGetRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IUser | null>>
+) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: ICompany | ICompanyAndRole | null = null;
+  let payload: IUser | null = null;
 
-  const companyIdNum = convertStringToNumber(req.query.companyId);
   const session = await getSession(req, res);
-  const { userId } = session;
-  const isAuth = await checkAuthorization([AuthFunctionsKeys.user], { userId });
-  if (!isAuth) {
-    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+  const { userId, companyId } = session;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
   } else {
-    const companyWithOwner = await getCompanyDetailAndRoleByCompanyId(userId, companyIdNum);
-    if (companyWithOwner) {
-      const companyDetailAndRole = formatCompanyDetailAndRole(companyWithOwner);
-      statusMessage = STATUS_MESSAGE.SUCCESS_GET;
-      payload = companyDetailAndRole;
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], { userId, companyId });
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
+      const getUser = await getUserById(userId);
+      if (!getUser) {
+        statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+      } else {
+        const user = formatUser(getUser);
+        statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+        payload = user;
+      }
     }
   }
 
   return { statusMessage, payload };
 }
 
-async function handlePutRequest(req: NextApiRequest, res: NextApiResponse) {
+async function handlePutRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IUser | null>>
+) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: ICompany | null = null;
+  let payload: IUser | null = null;
 
-  const companyIdNum = convertStringToNumber(req.query.companyId);
-  const { code, name, regional } = req.body;
-  const session = await getSession(req, res);
-  const { userId } = session;
-  const isAuth = await checkAuthorization([AuthFunctionsKeys.owner], {
-    userId,
-    companyId: companyIdNum,
-  });
-  if (!isAuth) {
-    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+  const queryUserId = req.query.userId as string;
+  const { name, fullName, email, phone, imageId } = req.body;
+  const isValid = await checkInput(queryUserId, name, fullName, email, phone);
+
+  if (!isValid) {
+    statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
   } else {
-    const getCompany = await getCompanyById(companyIdNum);
-    if (getCompany) {
-      const updatedCompany = await updateCompanyById(companyIdNum, code, name, regional);
-      const company = formatCompany(updatedCompany);
-      payload = company;
-    }
-    statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
-  }
+    const session = await getSession(req, res);
+    const { userId, companyId } = session;
 
-  return { statusMessage, payload };
-}
+    if (!userId) {
+      statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+    } else {
+      const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], {
+        userId,
+        companyId,
+      });
 
-async function handleDeleteRequest(req: NextApiRequest, res: NextApiResponse) {
-  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: ICompany | null = null;
+      if (!isAuth) {
+        statusMessage = STATUS_MESSAGE.FORBIDDEN;
+      } else {
+        const userIdNum = convertStringToNumber(queryUserId);
+        const getUser = await getUserById(userIdNum);
 
-  const companyIdNum = convertStringToNumber(req.query.companyId);
-  const session = await getSession(req, res);
-  const { userId } = session;
-  const isAuth = await checkAuthorization([AuthFunctionsKeys.owner], {
-    userId,
-    companyId: companyIdNum,
-  });
-  if (!isAuth) {
-    statusMessage = STATUS_MESSAGE.FORBIDDEN;
-  } else {
-    const getCompany = await getCompanyById(companyIdNum);
-    if (getCompany) {
-      const deletedCompany = await deleteCompanyById(companyIdNum);
-      await deleteAdminListByCompanyId(companyIdNum);
-      const company = formatCompany(deletedCompany);
-      payload = company;
+        if (!getUser) {
+          statusMessage = STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+        } else {
+          const updatedUser = await updateUserById(
+            userIdNum,
+            name,
+            fullName,
+            email,
+            phone,
+            imageId
+          );
+          const user = formatUser(updatedUser);
+          statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
+          payload = user;
+        }
+      }
     }
-    statusMessage = STATUS_MESSAGE.SUCCESS_DELETE;
   }
 
   return { statusMessage, payload };
@@ -98,19 +107,18 @@ const methodHandlers: {
   [key: string]: (
     req: NextApiRequest,
     res: NextApiResponse
-  ) => Promise<{ statusMessage: string; payload: ICompany | ICompanyAndRole | null }>;
+  ) => Promise<{ statusMessage: string; payload: IUser | null }>;
 } = {
   GET: handleGetRequest,
-  DELETE: handleDeleteRequest,
   PUT: handlePutRequest,
 };
 
 export default async function handler(
   req: NextApiRequest,
-  res: NextApiResponse<IResponseData<ICompany | ICompanyAndRole | null>>
+  res: NextApiResponse<IResponseData<IUser | null>>
 ) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: ICompany | ICompanyAndRole | null = null;
+  let payload: IUser | null = null;
 
   try {
     const handleRequest = methodHandlers[req.method || ''];
@@ -124,10 +132,7 @@ export default async function handler(
     statusMessage = error.message;
     payload = null;
   } finally {
-    const { httpCode, result } = formatApiResponse<ICompany | ICompanyAndRole | null>(
-      statusMessage,
-      payload
-    );
+    const { httpCode, result } = formatApiResponse<IUser | null>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }
diff --git a/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/[milestoneId]/index.ts b/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/[milestoneId]/index.ts
deleted file mode 100644
index 9b66eca16..000000000
--- a/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/[milestoneId]/index.ts
+++ /dev/null
@@ -1,91 +0,0 @@
-import { STATUS_MESSAGE } from '@/constants/status_code';
-import { IResponseData } from '@/interfaces/response_data';
-import { convertStringToNumber, formatApiResponse } from '@/lib/utils/common';
-import { checkAuthorization } from '@/lib/utils/auth_check';
-import { NextApiRequest, NextApiResponse } from 'next';
-import { IMilestone } from '@/interfaces/project';
-import { updateProjectMilestone } from '@/lib/utils/repo/transaction/project_milestone.tx';
-import { getSession } from '@/lib/utils/session';
-import { getProjectById } from '@/lib/utils/repo/project.repo';
-import { listProjectMilestone } from '@/lib/utils/repo/milestone.repo';
-import { formatMilestoneList } from '@/lib/utils/formatter/milestone.formatter';
-import { AuthFunctionsKeys } from '@/interfaces/auth';
-
-async function checkInput(projectId: string, stage: string, startDate: string) {
-  let isValid = true;
-  if (!stage || !startDate || !projectId) {
-    isValid = false;
-  }
-  return isValid;
-}
-
-async function checkAuth(userId: number, companyId: number, projectId: number) {
-  let isValid = true;
-  const isAdmin = await checkAuthorization([AuthFunctionsKeys.admin], { userId, companyId });
-  if (!isAdmin) {
-    isValid = false;
-  } else {
-    const project = await getProjectById(projectId);
-    if (!project || project.companyId !== companyId) {
-      isValid = false;
-    }
-  }
-
-  return isValid;
-}
-
-export default async function handler(
-  req: NextApiRequest,
-  res: NextApiResponse<IResponseData<IMilestone[]>>
-) {
-  let shouldContinue = true;
-  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: IMilestone[] = [];
-  try {
-    switch (req.method) {
-      case 'PUT': {
-        const { projectId } = req.query;
-        const { stage, startDate } = req.body;
-        // Info: (20240703 - Jacky) should convert to string
-        shouldContinue = await checkInput(
-          projectId as string,
-          stage as string,
-          startDate as string
-        );
-        // Info: (20240703 - Jacky) check authorization start
-        if (shouldContinue) {
-          const session = await getSession(req, res);
-          const { userId, companyId } = session;
-          const projectIdNum = convertStringToNumber(projectId);
-          shouldContinue = await checkAuth(userId, companyId, projectIdNum);
-          if (shouldContinue) {
-            const startDateNum = convertStringToNumber(startDate);
-            const listedMilestone = await listProjectMilestone(projectIdNum);
-            const milestoneList = formatMilestoneList(listedMilestone);
-            if (milestoneList.length === 0) {
-              statusMessage = STATUS_MESSAGE.RESOURCE_NOT_FOUND;
-            } else {
-              const { updatedMilestoneList } = await updateProjectMilestone(
-                projectIdNum,
-                milestoneList,
-                stage,
-                startDateNum
-              );
-              statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
-              payload = updatedMilestoneList;
-            }
-          }
-        }
-        break;
-      }
-      default:
-        statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
-    }
-  } catch (_error) {
-    const error = _error as Error;
-    statusMessage = error.message;
-    payload = [];
-  }
-  const { httpCode, result } = formatApiResponse<IMilestone[]>(statusMessage, payload);
-  res.status(httpCode).json(result);
-}
diff --git a/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/index.ts b/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/index.ts
index 19ef8a05f..01e6c0a85 100644
--- a/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/index.ts
+++ b/src/pages/api/v1/company/[companyId]/project/[projectId]/milestone/index.ts
@@ -1,77 +1,107 @@
 import { NextApiRequest, NextApiResponse } from 'next';
+import { IClient } from '@/interfaces/client';
 import { IResponseData } from '@/interfaces/response_data';
 import { STATUS_MESSAGE } from '@/constants/status_code';
-import { convertStringToNumber, formatApiResponse } from '@/lib/utils/common';
-import { checkAuthorization } from '@/lib/utils/auth_check';
-import { IMilestone } from '@/interfaces/project';
-import { listProjectMilestone } from '@/lib/utils/repo/milestone.repo';
-import { formatMilestoneList } from '@/lib/utils/formatter/milestone.formatter';
+import { formatApiResponse } from '@/lib/utils/common';
+import { deleteClientById, getClientById, updateClientById } from '@/lib/utils/repo/client.repo';
 import { getSession } from '@/lib/utils/session';
-import { getProjectById } from '@/lib/utils/repo/project.repo';
-import { AuthFunctionsKeys } from '@/interfaces/auth';
+import { getAdminByCompanyIdAndUserId } from '@/lib/utils/repo/admin.repo';
 
-async function checkInput(projectId: string) {
-  let isValid = true;
-  if (!projectId) {
-    isValid = false;
+async function checkAuth(userId: number, companyId: number): Promise<boolean> {
+  const admin = await getAdminByCompanyIdAndUserId(companyId, userId);
+  return !!admin;
+}
+
+async function handleGetRequest(req: NextApiRequest, res: NextApiResponse) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IClient | IClient[] | null = null;
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+  const isAuth = await checkAuth(userId, companyId);
+  if (!isAuth) {
+    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+  } else {
+    const clientIdNum = Number(req.query.clientId);
+    const getClient = await getClientById(clientIdNum);
+    statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+    payload = getClient;
   }
-  return isValid;
+  return { statusMessage, payload };
 }
 
-async function checkAuth(userId: number, companyId: number, projectId: number) {
-  let isValid = true;
-  const isAdmin = await checkAuthorization([AuthFunctionsKeys.admin], { userId, companyId });
-  if (!isAdmin) {
-    isValid = false;
+async function handlePutRequest(req: NextApiRequest, res: NextApiResponse) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IClient | IClient[] | null = null;
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+  const isAuth = await checkAuth(userId, companyId);
+  if (!isAuth) {
+    statusMessage = STATUS_MESSAGE.FORBIDDEN;
   } else {
-    const project = await getProjectById(projectId);
-    if (!project || project.companyId !== companyId) {
-      isValid = false;
-    }
+    const clientIdNum = Number(req.query.clientId);
+    const { name, taxId, favorite } = req.body;
+    const updatedClient = await updateClientById(clientIdNum, name, taxId, favorite);
+    statusMessage = updatedClient
+      ? STATUS_MESSAGE.SUCCESS_UPDATE
+      : STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+    payload = updatedClient;
   }
+  return { statusMessage, payload };
+}
 
-  return isValid;
+async function handleDeleteRequest(req: NextApiRequest, res: NextApiResponse) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IClient | IClient[] | null = null;
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+  const isAuth = await checkAuth(userId, companyId);
+  if (!isAuth) {
+    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+  } else {
+    const clientIdNum = Number(req.query.clientId);
+    const deletedClient = await deleteClientById(clientIdNum);
+    statusMessage = deletedClient
+      ? STATUS_MESSAGE.SUCCESS_DELETE
+      : STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+    payload = deletedClient;
+  }
+  return { statusMessage, payload };
 }
 
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: IClient | IClient[] | null }>;
+} = {
+  GET: handleGetRequest,
+  PUT: handlePutRequest,
+  DELETE: handleDeleteRequest,
+};
+
 export default async function handler(
   req: NextApiRequest,
-  res: NextApiResponse<IResponseData<IMilestone[]>>
+  res: NextApiResponse<IResponseData<IClient | IClient[] | null>>
 ) {
-  let shouldContinue = true;
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: IMilestone[] = [];
-  try {
-    switch (req.method) {
-      case 'GET': {
-        const { projectId } = req.query;
-        shouldContinue = await checkInput(projectId as string);
-        if (!shouldContinue) {
-          statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
-        } else {
-          const session = await getSession(req, res);
-          const { userId, companyId } = session;
-          const projectIdNum = convertStringToNumber(projectId);
+  let payload: IClient | IClient[] | null = null;
 
-          shouldContinue = await checkAuth(userId, companyId, projectIdNum);
-          if (!shouldContinue) {
-            statusMessage = STATUS_MESSAGE.FORBIDDEN;
-          } else {
-            const listedMilestone = await listProjectMilestone(projectIdNum);
-            const milestoneList = formatMilestoneList(listedMilestone);
-            statusMessage = STATUS_MESSAGE.SUCCESS_GET;
-            payload = milestoneList;
-          }
-        }
-        break;
-      }
-      default:
-        statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
+  try {
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
+    } else {
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
     statusMessage = error.message;
-    payload = [];
+    payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<IClient | IClient[] | null>(
+      statusMessage,
+      payload
+    );
+    res.status(httpCode).json(result);
   }
-  const { httpCode, result } = formatApiResponse<IMilestone[]>(statusMessage, payload);
-  res.status(httpCode).json(result);
 }
diff --git a/src/pages/api/v1/company/[companyId]/select.ts b/src/pages/api/v1/company/[companyId]/select.ts
index 5116c093d..af96ab6d3 100644
--- a/src/pages/api/v1/company/[companyId]/select.ts
+++ b/src/pages/api/v1/company/[companyId]/select.ts
@@ -10,23 +10,32 @@ import { formatCompany } from '@/lib/utils/formatter/company.formatter';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 import { NON_EXISTING_COMPANY_ID } from '@/constants/config';
 
-async function handlePutRequest(req: NextApiRequest, res: NextApiResponse) {
+async function handlePutRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<ICompany | null>>
+) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
   let payload: ICompany | null = null;
 
   const companyIdNum = convertStringToNumber(req.query.companyId);
   const session = await getSession(req, res);
   const { userId } = session;
-  const isAuth = await checkAuthorization([AuthFunctionsKeys.user], { userId });
-  if (!isAuth) {
-    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
   } else {
-    const getCompany = await getCompanyById(companyIdNum);
-    statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
-    const companyId = getCompany ? companyIdNum : NON_EXISTING_COMPANY_ID;
-    const company = getCompany ? formatCompany(getCompany) : null;
-    await setSession(session, undefined, companyId);
-    payload = company;
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.user], { userId });
+
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
+      const getCompany = await getCompanyById(companyIdNum);
+      statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
+      const companyId = getCompany ? companyIdNum : NON_EXISTING_COMPANY_ID;
+      const company = getCompany ? formatCompany(getCompany) : null;
+      await setSession(session, undefined, companyId);
+      payload = company;
+    }
   }
 
   return { statusMessage, payload };
diff --git a/src/pages/api/v1/company/[companyId]/transfer_owner.ts b/src/pages/api/v1/company/[companyId]/transfer_owner.ts
index a2b48e0db..c44056f9c 100644
--- a/src/pages/api/v1/company/[companyId]/transfer_owner.ts
+++ b/src/pages/api/v1/company/[companyId]/transfer_owner.ts
@@ -9,22 +9,33 @@ import { getSession } from '@/lib/utils/session';
 import { transferOwnership } from '@/lib/utils/repo/transaction/admin_role.tx';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 
-async function handlePutRequest(req: NextApiRequest, res: NextApiResponse) {
+async function handlePutRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IAdmin[] | null>>
+) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: IAdmin[] = [];
+  let payload: IAdmin[] | null = null;
+
   const { newOwnerId } = req.body;
   const newOwnerIdNum = convertStringToNumber(newOwnerId);
   const session = await getSession(req, res);
   const { userId, companyId } = session;
-  const isAuth = await checkAuthorization([AuthFunctionsKeys.owner], { userId, companyId });
-  if (!isAuth) {
-    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
   } else {
-    const updatedAdmin = await transferOwnership(userId, companyId, newOwnerIdNum);
-    const admin = await formatAdminList(updatedAdmin);
-    statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
-    payload = admin;
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.owner], { userId, companyId });
+
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
+      const updatedAdmin = await transferOwnership(userId, companyId, newOwnerIdNum);
+      const admin = await formatAdminList(updatedAdmin);
+      statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
+      payload = admin;
+    }
   }
+
   return { statusMessage, payload };
 }
 
@@ -42,7 +53,7 @@ export default async function handler(
   res: NextApiResponse<IResponseData<IAdmin[] | null>>
 ) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
-  let payload: IAdmin | IAdmin[] | null = null;
+  let payload: IAdmin[] | null = null;
 
   try {
     const handleRequest = methodHandlers[req.method || ''];
diff --git a/src/pages/api/v1/company/index.ts b/src/pages/api/v1/company/index.ts
index f69fd38e5..0633ed268 100644
--- a/src/pages/api/v1/company/index.ts
+++ b/src/pages/api/v1/company/index.ts
@@ -9,28 +9,104 @@ import {
   formatCompanyAndRoleList,
 } from '@/lib/utils/formatter/admin.formatter';
 import { createCompanyAndRole, listCompanyAndRole } from '@/lib/utils/repo/admin.repo';
-import { getUserById } from '@/lib/utils/repo/user.repo';
-import { getSession } from '@/lib/utils/session';
 import { getCompanyByCode } from '@/lib/utils/repo/company.repo';
 import { generateIcon } from '@/lib/utils/generate_user_icon';
+import { getSession } from '@/lib/utils/session';
+import { checkAuthorization } from '@/lib/utils/auth_check';
+import { AuthFunctionsKeys } from '@/interfaces/auth';
+
+async function checkInput(code: string, name: string, regional: string): Promise<boolean> {
+  return !!code && !!name && !!regional;
+}
+
+async function handleGetRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<Array<{ company: ICompany; role: IRole }> | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: Array<{ company: ICompany; role: IRole }> | null = null;
+  const session = await getSession(req, res);
+  const { userId } = session;
 
-async function checkAuth(userId: number) {
-  let isValid = true;
-  const getUser = await getUserById(userId);
-  if (!getUser) {
-    isValid = false;
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+  } else {
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.user], { userId });
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
+      const listedCompanyAndRole = await listCompanyAndRole(userId);
+      const companyAndRoleList = await formatCompanyAndRoleList(listedCompanyAndRole);
+      statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+      payload = companyAndRoleList;
+    }
   }
-  return isValid;
+
+  return { statusMessage, payload };
 }
 
-async function checkInput(code: string, name: string, regional: string) {
-  let isValid = true;
-  if (!code || !name || !regional) {
-    isValid = false;
+async function handlePostRequest(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<{ company: ICompany; role: IRole } | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: { company: ICompany; role: IRole } | null = null;
+  const { code, name, regional } = req.body;
+  const isValid = await checkInput(code, name, regional);
+
+  if (!isValid) {
+    statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
+  } else {
+    const session = await getSession(req, res);
+    const { userId } = session;
+
+    if (!userId) {
+      statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+    } else {
+      const isAuth = await checkAuthorization([AuthFunctionsKeys.user], { userId });
+
+      if (!isAuth) {
+        statusMessage = STATUS_MESSAGE.FORBIDDEN;
+      } else {
+        const getCompany = await getCompanyByCode(code);
+
+        if (getCompany) {
+          statusMessage = getCompany.kycStatus
+            ? STATUS_MESSAGE.DUPLICATE_COMPANY_KYC_DONE
+            : STATUS_MESSAGE.DUPLICATE_COMPANY;
+        } else {
+          const companyIcon = await generateIcon(name);
+          const createdCompanyRoleList = await createCompanyAndRole(
+            userId,
+            code,
+            name,
+            regional,
+            companyIcon
+          );
+          const newCompanyRoleList = await formatCompanyAndRole(createdCompanyRoleList);
+          statusMessage = STATUS_MESSAGE.CREATED;
+          payload = newCompanyRoleList;
+        }
+      }
+    }
   }
-  return isValid;
+
+  return { statusMessage, payload };
 }
 
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{
+    statusMessage: string;
+    payload: { company: ICompany; role: IRole } | Array<{ company: ICompany; role: IRole }> | null;
+  }>;
+} = {
+  GET: handleGetRequest,
+  POST: handlePostRequest,
+};
+
 export default async function handler(
   req: NextApiRequest,
   res: NextApiResponse<
@@ -46,66 +122,20 @@ export default async function handler(
     | null = null;
 
   try {
-    switch (req.method) {
-      case 'GET': {
-        const session = await getSession(req, res);
-        const { userId } = session;
-        const isAuth = await checkAuth(userId);
-        if (!isAuth) {
-          statusMessage = STATUS_MESSAGE.FORBIDDEN;
-        } else {
-          const listedCompanyAndRole = await listCompanyAndRole(userId);
-          const companyAndRoleList = await formatCompanyAndRoleList(listedCompanyAndRole);
-          statusMessage = STATUS_MESSAGE.SUCCESS_GET;
-          payload = companyAndRoleList;
-        }
-        break;
-      }
-      case 'POST': {
-        const { code, name, regional } = req.body;
-        const isValid = await checkInput(code, name, regional);
-        if (!isValid) {
-          statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
-        } else {
-          const session = await getSession(req, res);
-          const { userId } = session;
-          const isAuth = await checkAuth(userId);
-          if (!isAuth) {
-            statusMessage = STATUS_MESSAGE.FORBIDDEN;
-          } else {
-            const getCompany = await getCompanyByCode(code);
-            if (getCompany) {
-              statusMessage = getCompany.kycStatus
-                ? STATUS_MESSAGE.DUPLICATE_COMPANY_KYC_DONE
-                : STATUS_MESSAGE.DUPLICATE_COMPANY;
-            } else {
-              const companyIcon = await generateIcon(name);
-              const createdCompanyRoleList = await createCompanyAndRole(
-                userId,
-                code,
-                name,
-                regional,
-                companyIcon
-              );
-              const newCompanyRoleList = await formatCompanyAndRole(createdCompanyRoleList);
-              statusMessage = STATUS_MESSAGE.CREATED;
-              payload = newCompanyRoleList;
-            }
-          }
-        }
-        break;
-      }
-      default:
-        statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
+    } else {
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
     const error = _error as Error;
     statusMessage = error.message;
     payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<
+      { company: ICompany; role: IRole } | Array<{ company: ICompany; role: IRole }> | null
+    >(statusMessage, payload);
+    res.status(httpCode).json(result);
   }
-
-  const { httpCode, result } = formatApiResponse<
-    { company: ICompany; role: IRole } | Array<{ company: ICompany; role: IRole }> | null
-  >(statusMessage, payload);
-  res.status(httpCode).json(result);
 }
diff --git a/src/pages/api/v1/sign_in.ts b/src/pages/api/v1/sign_in.ts
index 9b07f1dce..f83127076 100644
--- a/src/pages/api/v1/sign_in.ts
+++ b/src/pages/api/v1/sign_in.ts
@@ -9,6 +9,7 @@ import { getSession, setSession } from '@/lib/utils/session';
 import { useInvitation } from '@/lib/utils/invitation';
 import { verifyChallengeTimestamp } from '@/lib/utils/authorization';
 import { getUserByCredential } from '@/lib/utils/repo/authentication.repo';
+import { formatUser } from '@/lib/utils/formatter/user.formatter';
 
 async function authenticateUser(
   authentication: AuthenticationEncoded,
@@ -38,6 +39,7 @@ async function authenticateUser(
       };
       try {
         await server.verifyAuthentication(authentication, registeredCredential, expected);
+        user = formatUser(getUser.user);
       } catch (error) {
         isValid = false;
         user = null;
diff --git a/src/pages/api/v1/user/[userId]/index.ts b/src/pages/api/v1/user/[userId]/index.ts
index 3d7ee2f8c..2187a83e2 100644
--- a/src/pages/api/v1/user/[userId]/index.ts
+++ b/src/pages/api/v1/user/[userId]/index.ts
@@ -16,7 +16,8 @@ async function checkInput(
   email: string,
   phone: string
 ): Promise<boolean> {
-  return !!userId && !!name && !!fullName && !!email && !!phone;
+  const isValid = !!userId && !!name && !!fullName && !!email && !!phone;
+  return isValid;
 }
 
 async function handleGetRequest(
@@ -25,21 +26,30 @@ async function handleGetRequest(
 ) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
   let payload: IUser | null = null;
+
   const session = await getSession(req, res);
-  const { userId, companyId } = session;
-  const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], { userId, companyId });
-  if (!isAuth) {
-    statusMessage = STATUS_MESSAGE.FORBIDDEN;
+  const { userId } = session;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
   } else {
-    const getUser = await getUserById(userId);
-    if (!getUser) {
-      statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.user], {
+      userId,
+    });
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
     } else {
-      const user = formatUser(getUser);
-      statusMessage = STATUS_MESSAGE.SUCCESS_GET;
-      payload = user;
+      const getUser = await getUserById(userId);
+      if (!getUser) {
+        statusMessage = STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+      } else {
+        const user = formatUser(getUser);
+        statusMessage = STATUS_MESSAGE.SUCCESS_GET;
+        payload = user;
+      }
     }
   }
+
   return { statusMessage, payload };
 }
 
@@ -49,30 +59,47 @@ async function handlePutRequest(
 ) {
   let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
   let payload: IUser | null = null;
+
   const queryUserId = req.query.userId as string;
   const { name, fullName, email, phone, imageId } = req.body;
   const isValid = await checkInput(queryUserId, name, fullName, email, phone);
+
   if (!isValid) {
     statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
   } else {
     const session = await getSession(req, res);
-    const { userId, companyId } = session;
-    const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], { userId, companyId });
-    if (!isAuth) {
-      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    const { userId } = session;
+
+    if (!userId) {
+      statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
     } else {
-      const userIdNum = convertStringToNumber(queryUserId);
-      const getUser = await getUserById(userIdNum);
-      if (!getUser) {
-        statusMessage = STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+      const isAuth = await checkAuthorization([AuthFunctionsKeys.user], {
+        userId,
+      });
+      if (!isAuth) {
+        statusMessage = STATUS_MESSAGE.FORBIDDEN;
       } else {
-        const updatedUser = await updateUserById(userIdNum, name, fullName, email, phone, imageId);
-        const user = formatUser(updatedUser);
-        statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
-        payload = user;
+        const userIdNum = convertStringToNumber(queryUserId);
+        const getUser = await getUserById(userIdNum);
+        if (!getUser) {
+          statusMessage = STATUS_MESSAGE.RESOURCE_NOT_FOUND;
+        } else {
+          const updatedUser = await updateUserById(
+            userIdNum,
+            name,
+            fullName,
+            email,
+            phone,
+            imageId
+          );
+          const user = await formatUser(updatedUser);
+          statusMessage = STATUS_MESSAGE.SUCCESS_UPDATE;
+          payload = user;
+        }
       }
     }
   }
+
   return { statusMessage, payload };
 }
 
diff --git a/src/pages/api/v1/user/[userId]/invitation.ts b/src/pages/api/v1/user/[userId]/invitation.ts
index a2b0d6c82..682d5fc0a 100644
--- a/src/pages/api/v1/user/[userId]/invitation.ts
+++ b/src/pages/api/v1/user/[userId]/invitation.ts
@@ -27,6 +27,9 @@ export default async function handler(
       case 'PUT': {
         const session = await getSession(req, res);
         const { userId } = session;
+        if (!userId) {
+          statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+        }
         const { invitation } = req.body;
         const isValid = await checkInput(invitation);
         if (!isValid) {
diff --git a/src/pages/api/v1/user/index.ts b/src/pages/api/v1/user/index.ts
index 7ff3d6c15..6406dae6d 100644
--- a/src/pages/api/v1/user/index.ts
+++ b/src/pages/api/v1/user/index.ts
@@ -9,45 +9,51 @@ import { formatUser, formatUserList } from '@/lib/utils/formatter/user.formatter
 import { getSession } from '@/lib/utils/session';
 import { AuthFunctionsKeys } from '@/interfaces/auth';
 
-export default async function handler(
-  req: NextApiRequest,
-  res: NextApiResponse<IResponseData<IUser | IUser[]>>
-) {
-  try {
-    // Todo: (20240419 - Jacky) add query like cursor, limit, etc.
-    if (req.method === 'GET') {
-      const session = await getSession(req, res);
-      const { userId, companyId } = session;
-      const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], {
-        userId,
-        companyId,
-      });
-      if (!isAuth) {
-        throw new Error(STATUS_MESSAGE.FORBIDDEN);
-      } else {
-        const listedUser = await listUser();
-        const userList: IUser[] = await formatUserList(listedUser);
-        const { httpCode, result } = formatApiResponse<IUser[]>(
-          STATUS_MESSAGE.SUCCESS_LIST,
-          userList
-        );
-        res.status(httpCode).json(result);
-      }
-    } else if (req.method === 'POST') {
-      // Handle POST request to create a new user
-      const { name, fullName, email, phone, credentialId, publicKey, algorithm, imageId } =
-        req.body;
-      if (!name || !credentialId || !publicKey || !algorithm) {
-        throw new Error(STATUS_MESSAGE.INVALID_INPUT_PARAMETER);
-      }
-      const session = await getSession(req, res);
-      const { userId, companyId } = session;
+async function handleGetRequest(req: NextApiRequest, res: NextApiResponse) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IUser | IUser[] | null = null;
+  const session = await getSession(req, res);
+  const { userId, companyId } = session;
+
+  if (!userId) {
+    statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+  } else {
+    const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], { userId, companyId });
+
+    if (!isAuth) {
+      statusMessage = STATUS_MESSAGE.FORBIDDEN;
+    } else {
+      const listedUser = await listUser();
+      const userList: IUser[] = await formatUserList(listedUser);
+      statusMessage = STATUS_MESSAGE.SUCCESS_LIST;
+      payload = userList;
+    }
+  }
+
+  return { statusMessage, payload };
+}
+
+async function handlePostRequest(req: NextApiRequest, res: NextApiResponse) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IUser | IUser[] | null = null;
+  const { name, fullName, email, phone, credentialId, publicKey, algorithm, imageId } = req.body;
+
+  if (!name || !credentialId || !publicKey || !algorithm) {
+    statusMessage = STATUS_MESSAGE.INVALID_INPUT_PARAMETER;
+  } else {
+    const session = await getSession(req, res);
+    const { userId, companyId } = session;
+
+    if (!userId) {
+      statusMessage = STATUS_MESSAGE.UNAUTHORIZED_ACCESS;
+    } else {
       const isAuth = await checkAuthorization([AuthFunctionsKeys.superAdmin], {
         userId,
         companyId,
       });
+
       if (!isAuth) {
-        throw new Error(STATUS_MESSAGE.FORBIDDEN);
+        statusMessage = STATUS_MESSAGE.FORBIDDEN;
       } else {
         const createdUser = await createUser({
           name,
@@ -57,17 +63,45 @@ export default async function handler(
           imageUrl: imageId,
         });
         const user = formatUser(createdUser);
-        const { httpCode, result } = formatApiResponse<IUser>(STATUS_MESSAGE.CREATED, user);
-        res.status(httpCode).json(result);
+        statusMessage = STATUS_MESSAGE.CREATED;
+        payload = user;
       }
+    }
+  }
+
+  return { statusMessage, payload };
+}
+
+const methodHandlers: {
+  [key: string]: (
+    req: NextApiRequest,
+    res: NextApiResponse
+  ) => Promise<{ statusMessage: string; payload: IUser | IUser[] | null }>;
+} = {
+  GET: handleGetRequest,
+  POST: handlePostRequest,
+};
+
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<IResponseData<IUser | IUser[] | null>>
+) {
+  let statusMessage: string = STATUS_MESSAGE.BAD_REQUEST;
+  let payload: IUser | IUser[] | null = null;
+
+  try {
+    const handleRequest = methodHandlers[req.method || ''];
+    if (handleRequest) {
+      ({ statusMessage, payload } = await handleRequest(req, res));
     } else {
-      // Handle unsupported HTTP methods
-      throw new Error(STATUS_MESSAGE.METHOD_NOT_ALLOWED);
+      statusMessage = STATUS_MESSAGE.METHOD_NOT_ALLOWED;
     }
   } catch (_error) {
-    // Handle errors
     const error = _error as Error;
-    const { httpCode, result } = formatApiResponse<IUser>(error.message, {} as IUser);
+    statusMessage = error.message;
+    payload = null;
+  } finally {
+    const { httpCode, result } = formatApiResponse<IUser | IUser[] | null>(statusMessage, payload);
     res.status(httpCode).json(result);
   }
 }