diff --git a/packages/core/src/database/insert.ts b/packages/core/src/database/insert.ts
new file mode 100644
index 000000000..b9b6eb50f
--- /dev/null
+++ b/packages/core/src/database/insert.ts
@@ -0,0 +1,87 @@
+import assert from 'assert';
+import RequestError from '@/errors/RequestError';
+import { SchemaLike, GeneratedSchema } from '@logto/schemas';
+import { DatabasePoolType, IdentifierSqlTokenType, sql } from 'slonik';
+import {
+  conditionalSql,
+  convertToIdentifiers,
+  convertToPrimitive,
+  excludeAutoSetFields,
+  OmitAutoSetFields,
+} from './utils';
+
+const setExcluded = (...fields: IdentifierSqlTokenType[]) =>
+  sql.join(
+    fields.map((field) => sql`${field}=excluded.${field}`),
+    sql`, `
+  );
+
+type OnConflict = {
+  fields: IdentifierSqlTokenType[];
+  setExcludedFields: IdentifierSqlTokenType[];
+};
+
+type InsertIntoConfigReturning = {
+  returning: true;
+  onConflict?: OnConflict;
+};
+
+type InsertIntoConfig = {
+  returning?: false;
+  onConflict?: OnConflict;
+};
+
+interface BuildInsertInto {
+  <Schema extends SchemaLike<string>>(
+    pool: DatabasePoolType,
+    { fieldKeys, ...rest }: GeneratedSchema<Schema>,
+    config: InsertIntoConfigReturning
+  ): (data: OmitAutoSetFields<Schema>) => Promise<Schema>;
+  <Schema extends SchemaLike<string>>(
+    pool: DatabasePoolType,
+    { fieldKeys, ...rest }: GeneratedSchema<Schema>,
+    config?: InsertIntoConfig
+  ): (data: OmitAutoSetFields<Schema>) => Promise<void>;
+}
+
+export const buildInsertInto: BuildInsertInto = <Schema extends SchemaLike<string>>(
+  pool: DatabasePoolType,
+  { fieldKeys, ...rest }: GeneratedSchema<Schema>,
+  config?: InsertIntoConfig | InsertIntoConfigReturning
+) => {
+  const { table, fields } = convertToIdentifiers(rest);
+  const keys = excludeAutoSetFields(fieldKeys);
+  const returning = Boolean(config?.returning);
+  const onConflict = config?.onConflict;
+
+  return async (data: OmitAutoSetFields<Schema>): Promise<Schema | void> => {
+    const result = await pool.query<Schema>(sql`
+    insert into ${table} (${sql.join(
+      keys.map((key) => fields[key]),
+      sql`, `
+    )})
+    values (${sql.join(
+      keys.map((key) => convertToPrimitive(data[key] ?? null)),
+      sql`, `
+    )})
+    ${conditionalSql(returning, () => sql`returning *`)}
+    ${conditionalSql(
+      onConflict,
+      ({ fields, setExcludedFields }) => sql`
+      on conflict (${sql.join(fields, sql`, `)}) do update
+      set ${setExcluded(...setExcludedFields)}
+    `
+    )}
+    `);
+
+    const {
+      rows: [entry],
+    } = result;
+
+    assert(
+      !returning || entry,
+      new RequestError({ code: 'entity.create_failed', name: rest.tableSingular })
+    );
+    return entry;
+  };
+};
diff --git a/packages/core/src/database/types.ts b/packages/core/src/database/types.ts
new file mode 100644
index 000000000..f47a8f0ca
--- /dev/null
+++ b/packages/core/src/database/types.ts
@@ -0,0 +1,6 @@
+import { IdentifierSqlTokenType } from 'slonik';
+
+export type Table = { table: string; fields: Record<string, string> };
+export type FieldIdentifiers<Key extends string | number | symbol> = {
+  [key in Key]: IdentifierSqlTokenType;
+};
diff --git a/packages/core/src/database/utils.ts b/packages/core/src/database/utils.ts
index 59a048c38..6dde30ea8 100644
--- a/packages/core/src/database/utils.ts
+++ b/packages/core/src/database/utils.ts
@@ -1,13 +1,51 @@
-import { IdentifierSqlTokenType, sql } from 'slonik';
+import { Falsy, notFalsy } from '@logto/essentials';
+import { SchemaValuePrimitive, SchemaValue } from '@logto/schemas';
+import { sql, SqlSqlTokenType } from 'slonik';
+import { FieldIdentifiers, Table } from './types';
 
-type Table = { table: string; fields: Record<string, string> };
-type FieldIdentifiers<Key extends string | number | symbol> = {
-  [key in Key]: IdentifierSqlTokenType;
+export const conditionalSql = <T>(
+  value: T,
+  buildSql: (value: Exclude<T, Falsy>) => SqlSqlTokenType
+) => (notFalsy(value) ? buildSql(value) : sql``);
+
+export const autoSetFields = Object.freeze(['createdAt', 'updatedAt'] as const);
+// `Except` type will require omit fields to be the key of given type
+// eslint-disable-next-line @typescript-eslint/ban-types
+export type OmitAutoSetFields<T> = Omit<T, typeof autoSetFields[number]>;
+export type ExcludeAutoSetFields<T> = Exclude<T, typeof autoSetFields[number]>;
+export const excludeAutoSetFields = <T extends string>(fields: readonly T[]) =>
+  Object.freeze(
+    fields.filter(
+      (field): field is ExcludeAutoSetFields<T> =>
+        !(autoSetFields as readonly string[]).includes(field)
+    )
+  );
+
+/**
+ * Note `undefined` is removed from the acceptable list,
+ * since you should NOT call this function if ignoring the field is the desired behavior.
+ * Calling this function with `null` means an explicit `null` setting in database is expected.
+ * @param value The value to convert.
+ * @returns A primitive that can be saved into database.
+ */
+export const convertToPrimitive = (
+  value: NonNullable<SchemaValue> | null
+): NonNullable<SchemaValuePrimitive> | null => {
+  if (value === null) {
+    return null;
+  }
+
+  if (typeof value === 'object') {
+    return JSON.stringify(value);
+  }
+
+  if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
+    return value;
+  }
+
+  throw new Error(`Cannot convert to primitive from ${typeof value}`);
 };
 
-const convertToPrimitive = <T>(value: T) =>
-  value !== null && typeof value === 'object' ? JSON.stringify(value) : value;
-
 export const convertToIdentifiers = <T extends Table>(
   { table, fields }: T,
   withPrefix = false
@@ -22,24 +60,3 @@ export const convertToIdentifiers = <T extends Table>(
     {} as FieldIdentifiers<keyof T['fields']>
   ),
 });
-
-export const insertInto = <Type, Key extends keyof Type = keyof Type>(
-  table: IdentifierSqlTokenType,
-  fields: FieldIdentifiers<Key>,
-  fieldKeys: readonly Key[],
-  value: { [key in Key]?: Type[key] }
-) => sql`
-  insert into ${table} (${sql.join(
-  fieldKeys.map((key) => fields[key]),
-  sql`, `
-)})
-  values (${sql.join(
-    fieldKeys.map((key) => convertToPrimitive(value[key] ?? null)),
-    sql`, `
-  )})`;
-
-export const setExcluded = (...fields: IdentifierSqlTokenType[]) =>
-  sql.join(
-    fields.map((field) => sql`${field}=excluded.${field}`),
-    sql`, `
-  );
diff --git a/packages/core/src/errors/RequestError/index.ts b/packages/core/src/errors/RequestError/index.ts
index d3992240b..5517d840e 100644
--- a/packages/core/src/errors/RequestError/index.ts
+++ b/packages/core/src/errors/RequestError/index.ts
@@ -10,8 +10,12 @@ export default class RequestError extends Error {
   data: unknown;
 
   constructor(input: RequestErrorMetadata | LogtoErrorCode, data?: unknown) {
-    const { code, status = 400 } = typeof input === 'string' ? { code: input } : input;
-    const message = i18next.t<string, LogtoErrorI18nKey>(`errors:${code}`);
+    const {
+      code,
+      status = 400,
+      ...interpolation
+    } = typeof input === 'string' ? { code: input } : input;
+    const message = i18next.t<string, LogtoErrorI18nKey>(`errors:${code}`, interpolation);
 
     super(message);
 
diff --git a/packages/core/src/oidc/adapter.ts b/packages/core/src/oidc/adapter.ts
index fcd1b6fa2..c671e1ad7 100644
--- a/packages/core/src/oidc/adapter.ts
+++ b/packages/core/src/oidc/adapter.ts
@@ -9,6 +9,7 @@ import {
 } from '@/queries/oidc-model-instance';
 import { findApplicationById } from '@/queries/application';
 import { ApplicationDBEntry } from '@logto/schemas';
+import dayjs from 'dayjs';
 
 export default function postgresAdapter(modelName: string): ReturnType<AdapterFactory> {
   if (modelName === 'Client') {
@@ -32,7 +33,13 @@ export default function postgresAdapter(modelName: string): ReturnType<AdapterFa
   }
 
   return {
-    upsert: async (id, payload, expiresIn) => upsertInstance(modelName, id, payload, expiresIn),
+    upsert: async (id, payload, expiresIn) =>
+      upsertInstance({
+        modelName,
+        id,
+        payload,
+        expiresAt: dayjs().add(expiresIn, 'second').unix(),
+      }),
     find: async (id) => findPayloadById(modelName, id),
     findByUserCode: async (userCode) => findPayloadByPayloadField(modelName, 'userCode', userCode),
     findByUid: async (uid) => findPayloadByPayloadField(modelName, 'uid', uid),
diff --git a/packages/core/src/oidc/utils.ts b/packages/core/src/oidc/utils.ts
new file mode 100644
index 000000000..8b6827531
--- /dev/null
+++ b/packages/core/src/oidc/utils.ts
@@ -0,0 +1,6 @@
+import { OidcClientMetadata } from '@logto/schemas';
+
+export const generateOidcClientMetadata = (): OidcClientMetadata => ({
+  redirect_uris: [],
+  post_logout_redirect_uris: [],
+});
diff --git a/packages/core/src/queries/application.ts b/packages/core/src/queries/application.ts
index fdc7df5db..29ecdc95b 100644
--- a/packages/core/src/queries/application.ts
+++ b/packages/core/src/queries/application.ts
@@ -1,3 +1,4 @@
+import { buildInsertInto } from '@/database/insert';
 import pool from '@/database/pool';
 import { convertToIdentifiers } from '@/database/utils';
 import { ApplicationDBEntry, Applications } from '@logto/schemas';
@@ -11,3 +12,7 @@ export const findApplicationById = async (id: string) =>
   from ${table}
   where ${fields.id}=${id}
 `);
+
+export const insertApplication = buildInsertInto<ApplicationDBEntry>(pool, Applications, {
+  returning: true,
+});
diff --git a/packages/core/src/queries/oidc-model-instance.ts b/packages/core/src/queries/oidc-model-instance.ts
index 35addb5cf..35f820d22 100644
--- a/packages/core/src/queries/oidc-model-instance.ts
+++ b/packages/core/src/queries/oidc-model-instance.ts
@@ -1,5 +1,6 @@
+import { buildInsertInto } from '@/database/insert';
 import pool from '@/database/pool';
-import { convertToIdentifiers, insertInto, setExcluded } from '@/database/utils';
+import { convertToIdentifiers } from '@/database/utils';
 import { conditional } from '@logto/essentials';
 import {
   OidcModelInstanceDBEntry,
@@ -22,30 +23,12 @@ const withConsumed = <T>(data: T, consumedAt?: number): WithConsumed<T> => ({
 const convertResult = (result: QueryResult | null) =>
   conditional(result && withConsumed(result.payload, result.consumedAt));
 
-export const upsertInstance = async (
-  modelName: string,
-  id: string,
-  payload: OidcModelInstancePayload,
-  expiresIn: number
-) => {
-  await pool.query(
-    sql`
-      ${insertInto<OidcModelInstanceDBEntry>(
-        table,
-        fields,
-        ['modelName', 'id', 'payload', 'expiresAt'],
-        {
-          modelName,
-          id,
-          payload,
-          expiresAt: dayjs().add(expiresIn, 'second').unix(),
-        }
-      )}
-      on conflict (${fields.modelName}, ${fields.id}) do update
-      set ${setExcluded(fields.payload, fields.expiresAt)}
-    `
-  );
-};
+export const upsertInstance = buildInsertInto<OidcModelInstanceDBEntry>(pool, OidcModelInstances, {
+  onConflict: {
+    fields: [fields.modelName, fields.id],
+    setExcludedFields: [fields.payload, fields.expiresAt],
+  },
+});
 
 const findByModel = (modelName: string) => sql`
   select ${fields.payload}, ${fields.consumedAt}
diff --git a/packages/core/src/queries/user.ts b/packages/core/src/queries/user.ts
index cc33cccfe..ed462b161 100644
--- a/packages/core/src/queries/user.ts
+++ b/packages/core/src/queries/user.ts
@@ -1,7 +1,8 @@
 import { UserDBEntry, Users } from '@logto/schemas';
 import { sql } from 'slonik';
 import pool from '@/database/pool';
-import { convertToIdentifiers, insertInto } from '@/database/utils';
+import { convertToIdentifiers } from '@/database/utils';
+import { buildInsertInto } from '@/database/insert';
 
 const { table, fields } = convertToIdentifiers(Users);
 
@@ -33,5 +34,4 @@ export const hasUserWithId = async (id: string) =>
   where ${fields.id}=${id}
 `);
 
-export const insertUser = async (user: UserDBEntry) =>
-  pool.query(insertInto(table, fields, Users.fieldKeys, user));
+export const insertUser = buildInsertInto<UserDBEntry>(pool, Users, { returning: true });
diff --git a/packages/core/src/routes/application.ts b/packages/core/src/routes/application.ts
index fa916e838..5c4a28d7f 100644
--- a/packages/core/src/routes/application.ts
+++ b/packages/core/src/routes/application.ts
@@ -2,6 +2,11 @@ import Router from 'koa-router';
 import { nativeEnum, object, string } from 'zod';
 import { ApplicationType } from '@logto/schemas';
 import koaGuard from '@/middleware/koa-guard';
+import { insertApplication } from '@/queries/application';
+import { buildIdGenerator } from '@/utils/id';
+import { generateOidcClientMetadata } from '@/oidc/utils';
+
+const applicationId = buildIdGenerator(21);
 
 export default function applicationRoutes<StateT, ContextT>(router: Router<StateT, ContextT>) {
   router.post(
@@ -15,7 +20,12 @@ export default function applicationRoutes<StateT, ContextT>(router: Router<State
     async (ctx, next) => {
       const { name, type } = ctx.guard.body;
 
-      ctx.body = { name, type };
+      ctx.body = await insertApplication({
+        id: applicationId(),
+        type,
+        name,
+        oidcClientMetadata: generateOidcClientMetadata(),
+      });
       return next();
     }
   );
diff --git a/packages/core/src/routes/user.ts b/packages/core/src/routes/user.ts
index 1d1a0af7f..3b5b1df90 100644
--- a/packages/core/src/routes/user.ts
+++ b/packages/core/src/routes/user.ts
@@ -2,13 +2,13 @@ import Router from 'koa-router';
 import { object, string } from 'zod';
 import { encryptPassword } from '@/utils/password';
 import { hasUser, hasUserWithId, insertUser } from '@/queries/user';
-import { customAlphabet, nanoid } from 'nanoid';
+import { nanoid } from 'nanoid';
 import { PasswordEncryptionMethod } from '@logto/schemas';
 import koaGuard from '@/middleware/koa-guard';
 import RequestError from '@/errors/RequestError';
+import { buildIdGenerator } from '@/utils/id';
 
-const alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
-const userId = customAlphabet(alphabet, 12);
+const userId = buildIdGenerator(12);
 
 const generateUserId = async (maxRetries = 500) => {
   for (let i = 0; i < maxRetries; ++i) {
@@ -48,15 +48,13 @@ export default function userRoutes(router: Router) {
         passwordEncryptionMethod
       );
 
-      await insertUser({
+      ctx.body = await insertUser({
         id,
         username,
         passwordEncrypted,
         passwordEncryptionMethod,
         passwordEncryptionSalt,
       });
-
-      ctx.body = { id };
       return next();
     }
   );
diff --git a/packages/core/src/utils/id.ts b/packages/core/src/utils/id.ts
new file mode 100644
index 000000000..5072c37ee
--- /dev/null
+++ b/packages/core/src/utils/id.ts
@@ -0,0 +1,5 @@
+import { customAlphabet } from 'nanoid';
+
+export const alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
+
+export const buildIdGenerator = (size: number) => customAlphabet(alphabet, size);
diff --git a/packages/phrases/src/locales/en.ts b/packages/phrases/src/locales/en.ts
index 7598e447f..eb7872cb9 100644
--- a/packages/phrases/src/locales/en.ts
+++ b/packages/phrases/src/locales/en.ts
@@ -37,6 +37,9 @@ const errors = {
   swagger: {
     invalid_zod_type: 'Invalid Zod type, please check route guard config.',
   },
+  entity: {
+    create_failed: 'Failed to create {{name}}.',
+  },
 };
 
 const en = Object.freeze({
diff --git a/packages/phrases/src/locales/zh-cn.ts b/packages/phrases/src/locales/zh-cn.ts
index 52785c233..02520a113 100644
--- a/packages/phrases/src/locales/zh-cn.ts
+++ b/packages/phrases/src/locales/zh-cn.ts
@@ -39,6 +39,9 @@ const errors = {
   swagger: {
     invalid_zod_type: '无效的 Zod 类型，请检查路由 guard 配置。',
   },
+  entity: {
+    create_failed: '创建{{name}}失败。',
+  },
 };
 
 const zhCN: typeof en = Object.freeze({
diff --git a/packages/schemas/src/api/error.ts b/packages/schemas/src/api/error.ts
index 147583635..ab5cb9c5f 100644
--- a/packages/schemas/src/api/error.ts
+++ b/packages/schemas/src/api/error.ts
@@ -1,6 +1,6 @@
 import { LogtoErrorCode } from '@logto/phrases';
 
-export type RequestErrorMetadata = {
+export type RequestErrorMetadata = Record<string, unknown> & {
   code: LogtoErrorCode;
   status?: number;
 };
diff --git a/packages/schemas/src/db-entries/application.ts b/packages/schemas/src/db-entries/application.ts
index f7be7c6b7..b4a3fbffd 100644
--- a/packages/schemas/src/db-entries/application.ts
+++ b/packages/schemas/src/db-entries/application.ts
@@ -1,6 +1,6 @@
 // THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
 
-import { OidcClientMetadata } from '../foundations';
+import { OidcClientMetadata, GeneratedSchema } from '../foundations';
 
 import { ApplicationType } from './custom-types';
 
@@ -12,8 +12,9 @@ export type ApplicationDBEntry = {
   createdAt: number;
 };
 
-export const Applications = Object.freeze({
+export const Applications: GeneratedSchema<ApplicationDBEntry> = Object.freeze({
   table: 'applications',
+  tableSingular: 'application',
   fields: {
     id: 'id',
     name: 'name',
@@ -22,4 +23,4 @@ export const Applications = Object.freeze({
     createdAt: 'created_at',
   },
   fieldKeys: ['id', 'name', 'type', 'oidcClientMetadata', 'createdAt'],
-} as const);
+});
diff --git a/packages/schemas/src/db-entries/oidc-model-instance.ts b/packages/schemas/src/db-entries/oidc-model-instance.ts
index 683952733..fcc6a71cf 100644
--- a/packages/schemas/src/db-entries/oidc-model-instance.ts
+++ b/packages/schemas/src/db-entries/oidc-model-instance.ts
@@ -1,6 +1,6 @@
 // THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
 
-import { OidcModelInstancePayload } from '../foundations';
+import { OidcModelInstancePayload, GeneratedSchema } from '../foundations';
 
 export type OidcModelInstanceDBEntry = {
   modelName: string;
@@ -10,8 +10,9 @@ export type OidcModelInstanceDBEntry = {
   consumedAt?: number;
 };
 
-export const OidcModelInstances = Object.freeze({
+export const OidcModelInstances: GeneratedSchema<OidcModelInstanceDBEntry> = Object.freeze({
   table: 'oidc_model_instances',
+  tableSingular: 'oidc_model_instance',
   fields: {
     modelName: 'model_name',
     id: 'id',
@@ -20,4 +21,4 @@ export const OidcModelInstances = Object.freeze({
     consumedAt: 'consumed_at',
   },
   fieldKeys: ['modelName', 'id', 'payload', 'expiresAt', 'consumedAt'],
-} as const);
+});
diff --git a/packages/schemas/src/db-entries/user.ts b/packages/schemas/src/db-entries/user.ts
index 370fad704..071f0f866 100644
--- a/packages/schemas/src/db-entries/user.ts
+++ b/packages/schemas/src/db-entries/user.ts
@@ -1,5 +1,7 @@
 // THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
 
+import { GeneratedSchema } from '../foundations';
+
 import { PasswordEncryptionMethod } from './custom-types';
 
 export type UserDBEntry = {
@@ -12,8 +14,9 @@ export type UserDBEntry = {
   passwordEncryptionSalt?: string;
 };
 
-export const Users = Object.freeze({
+export const Users: GeneratedSchema<UserDBEntry> = Object.freeze({
   table: 'users',
+  tableSingular: 'user',
   fields: {
     id: 'id',
     username: 'username',
@@ -32,4 +35,4 @@ export const Users = Object.freeze({
     'passwordEncryptionMethod',
     'passwordEncryptionSalt',
   ],
-} as const);
+});
diff --git a/packages/schemas/src/foundations.ts b/packages/schemas/src/foundations.ts
index fff2b7000..b6dae9b90 100644
--- a/packages/schemas/src/foundations.ts
+++ b/packages/schemas/src/foundations.ts
@@ -1,5 +1,21 @@
-export type OidcModelInstancePayload = {
-  [key: string]: unknown;
+export type SchemaValuePrimitive = string | number | boolean | undefined;
+export type SchemaValue = SchemaValuePrimitive | Record<string, unknown>;
+export type SchemaLike<Key extends string> = {
+  [key in Key]: SchemaValue;
+};
+
+export type GeneratedSchema<Schema extends SchemaLike<string>> = keyof Schema extends string
+  ? Readonly<{
+      table: string;
+      tableSingular: string;
+      fields: {
+        [key in keyof Schema]: string;
+      };
+      fieldKeys: ReadonlyArray<keyof Schema>;
+    }>
+  : never;
+
+export type OidcModelInstancePayload = Record<string, unknown> & {
   userCode?: string;
   uid?: string;
   grantId?: string;
diff --git a/packages/schemas/src/gen/index.ts b/packages/schemas/src/gen/index.ts
index 2ea9962b6..f33d0c34f 100644
--- a/packages/schemas/src/gen/index.ts
+++ b/packages/schemas/src/gen/index.ts
@@ -184,6 +184,10 @@ const generate = async () => {
         }),
       }));
 
+      if (tableWithTypes.length > 0) {
+        tsTypes.push('GeneratedSchema');
+      }
+
       const importTsTypes = conditionalString(
         tsTypes.length > 0 &&
           [
@@ -211,9 +215,13 @@ const generate = async () => {
         importTsTypes +
         importTypes +
         tableWithTypes
-          .map(({ name, fields }) =>
-            [
-              `export type ${pluralize(camelcase(name, { pascalCase: true }), 1)}DBEntry = {`,
+          .map(({ name, fields }) => {
+            const databaseEntryType = `${pluralize(
+              camelcase(name, { pascalCase: true }),
+              1
+            )}DBEntry`;
+            return [
+              `export type ${databaseEntryType} = {`,
               ...fields.map(
                 ({ name, type, isArray, required }) =>
                   `  ${camelcase(name)}${conditionalString(
@@ -222,17 +230,20 @@ const generate = async () => {
               ),
               '};',
               '',
-              `export const ${camelcase(name, { pascalCase: true })} = Object.freeze({`,
+              `export const ${camelcase(name, {
+                pascalCase: true,
+              })}: GeneratedSchema<${databaseEntryType}> = Object.freeze({`,
               `  table: '${name}',`,
+              `  tableSingular: '${pluralize(name, 1)}',`,
               '  fields: {',
               ...fields.map(({ name }) => `    ${camelcase(name)}: '${name}',`),
               '  },',
               '  fieldKeys: [',
               ...fields.map(({ name }) => `    '${camelcase(name)}',`),
               '  ],',
-              '} as const);',
-            ].join('\n')
-          )
+              '});',
+            ].join('\n');
+          })
           .join('\n') +
         '\n';
       await fs.writeFile(path.join(generatedDirectory, getOutputFileName(file) + '.ts'), content);