diff --git a/packages/core/package.json b/packages/core/package.json
index 4c5721ac5..bef60d062 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -13,18 +13,20 @@
   },
   "dependencies": {
     "@logto/essentials": "^1.0.5",
-    "@logto/schemas": "^1.0.1",
+    "@logto/schemas": "^1.0.3",
     "dayjs": "^1.10.5",
     "dotenv": "^10.0.0",
     "got": "^11.8.2",
     "koa": "^2.13.1",
+    "koa-body": "^4.2.0",
     "koa-logger": "^3.2.1",
     "koa-mount": "^4.0.0",
     "koa-router": "^10.0.0",
     "module-alias": "^2.2.2",
     "oidc-provider": "^7.4.1",
     "slonik": "^23.8.1",
-    "slonik-interceptor-preset": "^1.2.10"
+    "slonik-interceptor-preset": "^1.2.10",
+    "zod": "^3.2.0"
   },
   "devDependencies": {
     "@commitlint/cli": "^12.1.4",
diff --git a/packages/core/src/consts.ts b/packages/core/src/consts.ts
index 8aa908d72..f0c46b673 100644
--- a/packages/core/src/consts.ts
+++ b/packages/core/src/consts.ts
@@ -1,3 +1,3 @@
-import { assertEnv } from './utils';
+import { assertEnv } from '@/utils/env';
 
-export const signInRoute = assertEnv('SIGN_IN_ROUTE');
+export const signInRoute = assertEnv('UI_SIGN_IN_ROUTE');
diff --git a/packages/core/src/database/pool.ts b/packages/core/src/database/pool.ts
index 09d3f3e82..cdd826b93 100644
--- a/packages/core/src/database/pool.ts
+++ b/packages/core/src/database/pool.ts
@@ -1,6 +1,6 @@
 import { createPool } from 'slonik';
 import { createInterceptors } from 'slonik-interceptor-preset';
-import { getEnv } from '@/utils';
+import { getEnv } from '@/utils/env';
 
 const interceptors = [...createInterceptors()];
 
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 304e09120..77f47cd8c 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -5,7 +5,7 @@ dotenv.config();
 
 import Koa from 'koa';
 import initApp from './init';
-import { getEnv } from './utils';
+import { getEnv } from './utils/env';
 
 const app = new Koa();
 const port = Number(getEnv('PORT', '3001'));
diff --git a/packages/core/src/init/index.ts b/packages/core/src/init/index.ts
index 5688dd3b6..2b6fd92c6 100644
--- a/packages/core/src/init/index.ts
+++ b/packages/core/src/init/index.ts
@@ -6,8 +6,9 @@ import initRouter from './router';
 
 export default async function initApp(app: Koa, port: number): Promise<void> {
   app.use(logger());
-  await initOidc(app, port);
-  initRouter(app);
+
+  const provider = await initOidc(app, port);
+  initRouter(app, provider);
 
   app.listen(port, () => {
     console.log(`App is listening on port ${port}`);
diff --git a/packages/core/src/init/oidc.ts b/packages/core/src/init/oidc.ts
index a8195aacc..c499ea497 100644
--- a/packages/core/src/init/oidc.ts
+++ b/packages/core/src/init/oidc.ts
@@ -5,11 +5,11 @@ import { Provider } from 'oidc-provider';
 import postgresAdapter from '@/oidc/adapter';
 
 import { fromKeyLike } from 'jose/jwk/from_key_like';
-import { getEnv } from '@/utils';
+import { getEnv } from '@/utils/env';
 import { findUserById } from '@/queries/user';
 import { signInRoute } from '@/consts';
 
-export default async function initOidc(app: Koa, port: number): Promise<void> {
+export default async function initOidc(app: Koa, port: number): Promise<Provider> {
   const privateKey = crypto.createPrivateKey(
     Buffer.from(getEnv('OIDC_PROVIDER_PRIVATE_KEY_BASE64'), 'base64')
   );
@@ -41,7 +41,7 @@ export default async function initOidc(app: Koa, port: number): Promise<void> {
       devInteractions: { enabled: false },
     },
     interactions: {
-      url: (_, interaction) => `${signInRoute}?uid=${interaction.uid}`,
+      url: (_) => signInRoute,
     },
     clientBasedCORS: (_, origin) => {
       console.log('origin', origin);
@@ -63,4 +63,5 @@ export default async function initOidc(app: Koa, port: number): Promise<void> {
     },
   });
   app.use(mount('/oidc', oidc.app));
+  return oidc;
 }
diff --git a/packages/core/src/init/router.ts b/packages/core/src/init/router.ts
index fbe8a995d..379548630 100644
--- a/packages/core/src/init/router.ts
+++ b/packages/core/src/init/router.ts
@@ -1,19 +1,20 @@
-import got from 'got';
 import Koa from 'koa';
 import Router from 'koa-router';
-import { promisify } from 'util';
-import stream from 'stream';
-import { signInRoute } from '@/consts';
-import { getEnv } from '@/utils';
+import { Provider } from 'oidc-provider';
+import createSignInRoutes from '@/routes/sign-in';
+import createUIRoutes from '@/routes/ui';
 
-const pipeline = promisify(stream.pipeline);
-const router = new Router();
+const createRouter = (provider: Provider): Router => {
+  const router = new Router();
 
-router.get(new RegExp(`^${signInRoute}(?:/|$)`), async (ctx) => {
-  // CAUTION: this is for dev purpose only, add a switch if needed
-  await pipeline(got.stream.get(getEnv('PLAYGROUND_URL')), ctx.res);
-});
+  router.use('/api', createSignInRoutes());
+  router.use(createUIRoutes(provider));
 
-export default function initRouter(app: Koa): void {
+  return router;
+};
+
+export default function initRouter(app: Koa, provider: Provider): Router {
+  const router = createRouter(provider);
   app.use(router.routes()).use(router.allowedMethods());
+  return router;
 }
diff --git a/packages/core/src/routes/sign-in.ts b/packages/core/src/routes/sign-in.ts
new file mode 100644
index 000000000..87312973b
--- /dev/null
+++ b/packages/core/src/routes/sign-in.ts
@@ -0,0 +1,30 @@
+import assert from 'assert';
+import Router from 'koa-router';
+import koaBody from 'koa-body';
+import { object, string } from 'zod';
+import { encryptPassword } from '@/utils/password';
+import { findUserById } from '@/queries/user';
+
+export default function createSignInRoutes() {
+  const router = new Router();
+
+  router.post('/sign-in', koaBody(), async (ctx) => {
+    const SignInBody = object({
+      id: string().min(1),
+      password: string().min(1),
+    });
+    const { id, password } = SignInBody.parse(ctx.request.body);
+    const { passwordEncrypted, passwordEncryptionMethod, passwordEncryptionSalt } =
+      await findUserById(id);
+
+    assert(passwordEncrypted && passwordEncryptionMethod && passwordEncryptionSalt);
+    assert(
+      encryptPassword(id, password, passwordEncryptionSalt, passwordEncryptionMethod) ===
+        passwordEncrypted
+    );
+
+    ctx.status = 204;
+  });
+
+  return router.routes();
+}
diff --git a/packages/core/src/routes/ui.ts b/packages/core/src/routes/ui.ts
new file mode 100644
index 000000000..29a490b25
--- /dev/null
+++ b/packages/core/src/routes/ui.ts
@@ -0,0 +1,20 @@
+import got from 'got';
+import Router from 'koa-router';
+import { promisify } from 'util';
+import stream from 'stream';
+import { signInRoute } from '@/consts';
+import { getEnv } from '@/utils/env';
+import { Provider } from 'oidc-provider';
+
+export default function createUIRoutes(provider: Provider) {
+  const pipeline = promisify(stream.pipeline);
+  const router = new Router();
+
+  router.get(new RegExp(`^${signInRoute}(?:/|$)`), async (ctx) => {
+    const details = await provider.interactionDetails(ctx.req, ctx.res);
+    console.log('details', details);
+    // CAUTION: this is for dev purpose only, add a switch if needed
+    await pipeline(got.stream.get(getEnv('UI_PLAYGROUND_URL')), ctx.res);
+  });
+  return router.routes();
+}
diff --git a/packages/core/src/utils.ts b/packages/core/src/utils/env.ts
similarity index 100%
rename from packages/core/src/utils.ts
rename to packages/core/src/utils/env.ts
diff --git a/packages/core/src/utils/password.ts b/packages/core/src/utils/password.ts
new file mode 100644
index 000000000..ced5b1c83
--- /dev/null
+++ b/packages/core/src/utils/password.ts
@@ -0,0 +1,39 @@
+import assert from 'assert';
+import { createHash } from 'crypto';
+import { PasswordEncryptionMethod } from '@logto/schemas';
+import { number, string } from 'zod';
+import { assertEnv } from './env';
+
+const peppers = string()
+  .array()
+  .parse(JSON.parse(assertEnv('PASSWORD_PEPPERS')));
+const iterationCount = number()
+  .min(100)
+  .parse(Number(assertEnv('PASSWORD_INTERATION_COUNT')));
+
+export const encryptPassword = (
+  id: string,
+  password: string,
+  salt: string,
+  method: PasswordEncryptionMethod
+): string => {
+  assert(
+    method === PasswordEncryptionMethod.SaltAndPepper,
+    'Unsupported password encryption method'
+  );
+
+  const sum = [...id].reduce((acc, current) => acc + current.charCodeAt(0), 0);
+  const pepper = peppers[sum % peppers.length];
+
+  assert(pepper, 'Password pepper not found');
+
+  let result = password;
+
+  for (let i = 0; i < iterationCount; ++i) {
+    result = createHash('sha256')
+      .update(salt + result + pepper)
+      .digest('hex');
+  }
+
+  return result;
+};
diff --git a/packages/core/yarn.lock b/packages/core/yarn.lock
index 97ed8d583..e2e35032c 100644
--- a/packages/core/yarn.lock
+++ b/packages/core/yarn.lock
@@ -396,10 +396,10 @@
     lodash.orderby "^4.6.0"
     lodash.pick "^4.4.0"
 
-"@logto/schemas@^1.0.1":
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/@logto/schemas/-/schemas-1.0.1.tgz#786866a280568b275b9c55c2b884b5864dc42a06"
-  integrity sha512-SwAz/rOE61RDBU3TzsDqO30vkLRgD/Jcc3H3tC40gl39wTfxWiTrXgGtWTxAhrhdTwstEMa5+5ozczP/LvopwQ==
+"@logto/schemas@^1.0.3":
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/@logto/schemas/-/schemas-1.0.3.tgz#6a596bb9d1b99460857eaec5d643040ae384e037"
+  integrity sha512-inCo/PQUQl9OZFkjehjcB/4PBzYBW9FVn/3nZ2CPr/+3dJKDF3B0qxu8gyQICGJuWYx1BZPygc/NvV0F1klR3g==
 
 "@mrmlnc/readdir-enhanced@^2.2.1":
   version "2.2.1"
@@ -538,6 +538,13 @@
     "@types/qs" "*"
     "@types/serve-static" "*"
 
+"@types/formidable@^1.0.31":
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/@types/formidable/-/formidable-1.2.2.tgz#e690d60732ee9d3f0a441bc572c17409785b283c"
+  integrity sha512-8RDAMnMHOh7QrY1xuQ7s6/Xre9pMvJ2zT2VgATiz5cIE71Q/6N3+P8sr3z/dNWNmvX5/aX9x8uJlG0MZiMZXoA==
+  dependencies:
+    "@types/node" "*"
+
 "@types/glob@^7.1.1":
   version "7.1.3"
   resolved "https://registry.yarnpkg.com/@types/glob/-/glob-7.1.3.tgz#e6ba80f36b7daad2c685acd9266382e68985c183"
@@ -1276,6 +1283,16 @@ clone-response@^1.0.2:
   dependencies:
     mimic-response "^1.0.0"
 
+co-body@^5.1.1:
+  version "5.2.0"
+  resolved "https://registry.yarnpkg.com/co-body/-/co-body-5.2.0.tgz#5a0a658c46029131e0e3a306f67647302f71c124"
+  integrity sha512-sX/LQ7LqUhgyaxzbe7IqwPeTr2yfpfUIQ/dgpKo6ZI4y4lpQA0YxAomWIY+7I7rHWcG02PG+OuPREzMW/5tszQ==
+  dependencies:
+    inflation "^2.0.0"
+    qs "^6.4.0"
+    raw-body "^2.2.0"
+    type-is "^1.6.14"
+
 co@^4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/co/-/co-4.6.0.tgz#6ea6bdf3d853ae54ccb8e47bfa0bf3f9031fb184"
@@ -2374,6 +2391,11 @@ for-in@^1.0.2:
   resolved "https://registry.yarnpkg.com/for-in/-/for-in-1.0.2.tgz#81068d295a8142ec0ac726c6e2200c30fb6d5e80"
   integrity sha1-gQaNKVqBQuwKxybG4iAMMPttXoA=
 
+formidable@^1.1.1:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/formidable/-/formidable-1.2.2.tgz#bf69aea2972982675f00865342b982986f6b8dd9"
+  integrity sha512-V8gLm+41I/8kguQ4/o1D3RIHRmhYFG4pnNyonvua+40rqcEmT4+V71yaZ3B457xbbgCsCfjSPi65u/W6vK1U5Q==
+
 fragment-cache@^0.2.1:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/fragment-cache/-/fragment-cache-0.2.1.tgz#4290fad27f13e89be7f33799c6bc5a0abfff0d19"
@@ -2814,6 +2836,11 @@ indent-string@^4.0.0:
   resolved "https://registry.yarnpkg.com/indent-string/-/indent-string-4.0.0.tgz#624f8f4497d619b2d9768531d58f4122854d7251"
   integrity sha512-EdDDZu4A2OyIK7Lr/2zG+w5jmbuk1DVBnEwREQvBzspBJkCEbRa8GxU1lghYcaGJCnRWibjDXlq779X1/y5xwg==
 
+inflation@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/inflation/-/inflation-2.0.0.tgz#8b417e47c28f925a45133d914ca1fd389107f30f"
+  integrity sha1-i0F+R8KPklpFEz2RTKH9OJEH8w8=
+
 inflight@^1.0.4:
   version "1.0.6"
   resolved "https://registry.yarnpkg.com/inflight/-/inflight-1.0.6.tgz#49bd6331d7d02d0c09bc910a1075ba8165b56df9"
@@ -3375,6 +3402,15 @@ kind-of@^6.0.0, kind-of@^6.0.2, kind-of@^6.0.3:
   resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-6.0.3.tgz#07c05034a6c349fa06e24fa35aa76db4580ce4dd"
   integrity sha512-dcS1ul+9tmeD95T+x28/ehLgd9mENa3LsvDTtzm3vyBEO7RPptvAD+t44WVXaUjTBRcrpFeFlC8WCruUR456hw==
 
+koa-body@^4.2.0:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/koa-body/-/koa-body-4.2.0.tgz#37229208b820761aca5822d14c5fc55cee31b26f"
+  integrity sha512-wdGu7b9amk4Fnk/ytH8GuWwfs4fsB5iNkY8kZPpgQVb04QZSv85T0M8reb+cJmvLE8cjPYvBzRikD3s6qz8OoA==
+  dependencies:
+    "@types/formidable" "^1.0.31"
+    co-body "^5.1.1"
+    formidable "^1.1.1"
+
 koa-compose@^3.0.0:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/koa-compose/-/koa-compose-3.2.1.tgz#a85ccb40b7d986d8e5a345b3a1ace8eabcf54de7"
@@ -3882,7 +3918,7 @@ object-hash@^2.0.3:
   resolved "https://registry.yarnpkg.com/object-hash/-/object-hash-2.2.0.tgz#5ad518581eefc443bd763472b8ff2e9c2c0d54a5"
   integrity sha512-gScRMn0bS5fH+IuwyIFgnh9zBdo4DV+6GhygmWM9HyNJSgS0hScp1f5vjtm7oIIOiT9trXrShAkLFSc2IqKNgw==
 
-object-inspect@^1.10.3:
+object-inspect@^1.10.3, object-inspect@^1.9.0:
   version "1.10.3"
   resolved "https://registry.yarnpkg.com/object-inspect/-/object-inspect-1.10.3.tgz#c2aa7d2d09f50c99375704f7a0adf24c5782d369"
   integrity sha512-e5mCJlSH7poANfC8z8S9s9S2IN5/4Zb3aZ33f5s8YqoazCFzNLloLU8r5VCG+G7WoqLvAAZoVMcy3tp/3X0Plw==
@@ -4486,6 +4522,13 @@ q@^1.5.1:
   resolved "https://registry.yarnpkg.com/q/-/q-1.5.1.tgz#7e32f75b41381291d04611f1bf14109ac00651d7"
   integrity sha1-fjL3W0E4EpHQRhHxvxQQmsAGUdc=
 
+qs@^6.4.0:
+  version "6.10.1"
+  resolved "https://registry.yarnpkg.com/qs/-/qs-6.10.1.tgz#4931482fa8d647a5aab799c5271d2133b981fb6a"
+  integrity sha512-M528Hph6wsSVOBiYUnGf+K/7w0hNshs/duGsNXPUCLH5XAqjEtiPGwNONLV0tBH8NoGb0mvD5JubnUTrujKDTg==
+  dependencies:
+    side-channel "^1.0.4"
+
 queue-microtask@^1.2.2:
   version "1.2.3"
   resolved "https://registry.yarnpkg.com/queue-microtask/-/queue-microtask-1.2.3.tgz#4929228bbc724dfac43e0efb058caf7b6cfb6243"
@@ -4501,7 +4544,7 @@ quick-lru@^5.1.1:
   resolved "https://registry.yarnpkg.com/quick-lru/-/quick-lru-5.1.1.tgz#366493e6b3e42a3a6885e2e99d18f80fb7a8c932"
   integrity sha512-WuyALRjWPDGtt/wzJiadO5AXY+8hZ80hVpe6MyivgraREW751X3SbhRvG3eLKOYN+8VEvqLcf3wdnt44Z4S4SA==
 
-raw-body@^2.4.1:
+raw-body@^2.2.0, raw-body@^2.4.1:
   version "2.4.1"
   resolved "https://registry.yarnpkg.com/raw-body/-/raw-body-2.4.1.tgz#30ac82f98bb5ae8c152e67149dac8d55153b168c"
   integrity sha512-9WmIKF6mkvA0SLmA2Knm9+qj89e+j1zqgyn8aXGd7+nAduPoqgI9lO57SAZNn/Byzo5P7JhXTyg9PzaJbH73bA==
@@ -4863,6 +4906,15 @@ shell-quote@^1.7.2:
   resolved "https://registry.yarnpkg.com/shell-quote/-/shell-quote-1.7.2.tgz#67a7d02c76c9da24f99d20808fcaded0e0e04be2"
   integrity sha512-mRz/m/JVscCrkMyPqHc/bczi3OQHkLTqXHEFu0zDhK/qfv3UcOA4SVmRCLmos4bhjr9ekVQubj/R7waKapmiQg==
 
+side-channel@^1.0.4:
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/side-channel/-/side-channel-1.0.4.tgz#efce5c8fdc104ee751b25c58d4290011fa5ea2cf"
+  integrity sha512-q5XPytqFEIKHkGdiMIrY10mvLRvnQh42/+GoBlFW3b2LXLE2xxJpZFdm94we0BaoV3RwJyGqg5wS7epxTv0Zvw==
+  dependencies:
+    call-bind "^1.0.0"
+    get-intrinsic "^1.0.2"
+    object-inspect "^1.9.0"
+
 signal-exit@^3.0.2, signal-exit@^3.0.3:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/signal-exit/-/signal-exit-3.0.3.tgz#a1410c2edd8f077b08b4e253c8eacfcaf057461c"
@@ -5452,7 +5504,7 @@ type-fest@^0.8.0, type-fest@^0.8.1:
   resolved "https://registry.yarnpkg.com/type-fest/-/type-fest-0.8.1.tgz#09e249ebde851d3b1e48d27c105444667f17b83d"
   integrity sha512-4dbzIzqvjtgiM5rw1k5rEHtBANKmdudhGyBEajN01fEyhaAIhsoKNy6y7+IN93IfpFtwY9iqi7kD+xwKhQsNJA==
 
-type-is@^1.6.16:
+type-is@^1.6.14, type-is@^1.6.16:
   version "1.6.18"
   resolved "https://registry.yarnpkg.com/type-is/-/type-is-1.6.18.tgz#4e552cd05df09467dcbc4ef739de89f2cf37c131"
   integrity sha512-TkRKr9sUTxEH8MdfuCSP7VizJyzRNMjj2J2do2Jr3Kym598JVdEksuzPQCnlFPW4ky9Q+iA+ma9BGm06XQBy8g==
@@ -5792,3 +5844,8 @@ yocto-queue@^0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/yocto-queue/-/yocto-queue-0.1.0.tgz#0294eb3dee05028d31ee1a5fa2c556a6aaf10a1b"
   integrity sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q==
+
+zod@^3.2.0:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/zod/-/zod-3.2.0.tgz#4f06fac3c74e56902eae43a47a1687bf49c9b70b"
+  integrity sha512-yvcO3FZ8URR+LliMGqaW7tlVOOTzmup3vzKEe9Ds7twyJtdhvYa7dIYr0FbD1wVfWC1OuS83vZfHtCKslPuRhA==