diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cc24903..463577f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,3 +26,5 @@ jobs:
           JWT_SECRET: "ci-placeholder-jwt-secret-min-32-chars"
           DATABASE_URL: "postgresql://placeholder:placeholder@localhost:5432/placeholder"
           DIRECT_URL: "postgresql://placeholder:placeholder@localhost:5432/placeholder"
+          ADMIN_USERNAME: "ci-admin-user"
+          ADMIN_PASSWORD: "ci-placeholder-admin-password-min-8-chars"
diff --git a/.jules/sentinel.md b/.jules/sentinel.md
new file mode 100644
index 0000000..fe20748
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,5 @@
+
+## 2024-05-24 - [CRITICAL] Fix Hardcoded Admin Credentials in Authentication Logic
+**Vulnerability:** Found hardcoded `ADMIN_USERNAME` and `ADMIN_PASSWORD` in `packages/web/src/lib/server/admin-auth.ts`.
+**Learning:** Hardcoding credentials in source code exposes them to anyone with read access to the repository and makes it impossible to securely manage or rotate these secrets across different environments.
+**Prevention:** Always use environment variables for secrets and credentials. Use tools like `zod` to validate their presence at runtime (e.g., in `env.ts`) and ensure proper placeholder values are added to `.env.example` and CI workflows to prevent build regressions.
diff --git a/packages/web/.env.example b/packages/web/.env.example
index e99d51e..c139f14 100644
--- a/packages/web/.env.example
+++ b/packages/web/.env.example
@@ -4,3 +4,7 @@ AUTH_SECRET=replace-with-min-32-char-random-string
 DATABASE_URL="postgresql://postgres.[project]:[password]@aws-0-ap-northeast-1.pooler.supabase.com:6543/postgres?pgbouncer=true"
 DIRECT_URL="postgresql://postgres.[project]:[password]@db.uwxfseowdzuuepeeudrx.supabase.co:5432/postgres"
 JWT_SECRET="replace-with-32-char-minimum-random-string"
+
+# Admin credentials
+ADMIN_USERNAME=admin
+ADMIN_PASSWORD=replace-with-secure-admin-password
diff --git a/packages/web/src/app/api/admin/login/route.ts b/packages/web/src/app/api/admin/login/route.ts
index dbf5d2e..24fabdb 100644
--- a/packages/web/src/app/api/admin/login/route.ts
+++ b/packages/web/src/app/api/admin/login/route.ts
@@ -20,7 +20,7 @@ const AdminLoginSchema = z.object({
 export async function POST(req: Request) {
   try {
     const input = AdminLoginSchema.parse(await req.json())
-    if (!verifyAdminCredentials(input)) {
+    if (!(await verifyAdminCredentials(input))) {
       return NextResponse.json({ error: 'Invalid username or password' }, { status: 401 })
     }
 
diff --git a/packages/web/src/lib/server/admin-auth.ts b/packages/web/src/lib/server/admin-auth.ts
index 5390fa4..4658ef9 100644
--- a/packages/web/src/lib/server/admin-auth.ts
+++ b/packages/web/src/lib/server/admin-auth.ts
@@ -1,19 +1,37 @@
 import 'server-only'
 
-import { createHmac, randomBytes, timingSafeEqual } from 'crypto'
+import { createHmac, randomBytes, timingSafeEqual, pbkdf2Sync, pbkdf2 } from 'crypto'
+import { promisify } from 'util'
 import { cookies } from 'next/headers'
 import { NextRequest, NextResponse } from 'next/server'
 
 import { env } from './env'
 
-export const ADMIN_USERNAME = 'admin'
-export const ADMIN_PASSWORD = 'og9oRajx7h88v1RIj3eDgdrh9jgLYVV3'
+export const ADMIN_USERNAME = env.ADMIN_USERNAME
+export const ADMIN_PASSWORD = env.ADMIN_PASSWORD
 
 const ADMIN_SESSION_COOKIE = 'argos_admin_session'
 const ADMIN_SESSION_TTL_MS = 12 * 60 * 60 * 1000
 const ADMIN_IMPERSONATION_TTL_MS = 60 * 1000
 const ADMIN_IMPERSONATION_PREFIX = 'argos_imp'
 
+const pbkdf2Async = promisify(pbkdf2)
+
+// PBKDF2 parameters for secure password hashing
+const HASH_SALT = 'argos_admin_salt'
+const HASH_ITERATIONS = 100000
+const HASH_KEYLEN = 64
+const HASH_DIGEST = 'sha512'
+
+// Pre-compute the target hash of the admin password at module initialization
+const TARGET_PASSWORD_HASH = pbkdf2Sync(
+  ADMIN_PASSWORD,
+  HASH_SALT,
+  HASH_ITERATIONS,
+  HASH_KEYLEN,
+  HASH_DIGEST
+)
+
 function safeEqual(a: string, b: string): boolean {
   const aHash = createHmac('sha256', env.JWT_SECRET).update(a).digest()
   const bHash = createHmac('sha256', env.JWT_SECRET).update(b).digest()
@@ -24,14 +42,24 @@ function sign(payload: string): string {
   return createHmac('sha256', env.JWT_SECRET).update(payload).digest('base64url')
 }
 
-export function verifyAdminCredentials(input: {
+export async function verifyAdminCredentials(input: {
   username: string
   password: string
-}): boolean {
-  return (
-    safeEqual(input.username, ADMIN_USERNAME) &&
-    safeEqual(input.password, ADMIN_PASSWORD)
+}): Promise<boolean> {
+  if (!safeEqual(input.username, ADMIN_USERNAME)) {
+    return false
+  }
+
+  // Hash the incoming password asynchronously to avoid blocking the event loop
+  const inputPasswordHash = await pbkdf2Async(
+    input.password,
+    HASH_SALT,
+    HASH_ITERATIONS,
+    HASH_KEYLEN,
+    HASH_DIGEST
   )
+
+  return timingSafeEqual(inputPasswordHash, TARGET_PASSWORD_HASH)
 }
 
 export function createAdminSessionCookieValue(): string {
diff --git a/packages/web/src/lib/server/env.ts b/packages/web/src/lib/server/env.ts
index 86ed9a3..6bdf299 100644
--- a/packages/web/src/lib/server/env.ts
+++ b/packages/web/src/lib/server/env.ts
@@ -5,6 +5,8 @@ const EnvSchema = z.object({
   DATABASE_URL: z.string().min(1),
   DIRECT_URL: z.string().min(1),
   JWT_SECRET: z.string().min(32),
+  ADMIN_USERNAME: z.string().trim().min(1),
+  ADMIN_PASSWORD: z.string().trim().min(8),
 })
 
 export const env = EnvSchema.parse(process.env)