fix: treat generateId "serial" as numeric ID and correct UUID column types across adapters (#5823)

packages/better-auth/src/__snapshots__/init.test.ts.snap

@@ -22,6 +22,7 @@ exports[`init > should match config 1`] = `
         "supportsDates": false,
         "supportsJSON": false,
         "supportsNumericIds": true,
+        "supportsUUIDs": false,
         "transaction": false,
         "usePlural": undefined,
       },

packages/better-auth/src/adapters/adapter-factory/index.ts

@@ -49,6 +49,7 @@ export const createAdapterFactory =
 			supportsJSON: cfg.supportsJSON ?? false,
 			adapterName: cfg.adapterName ?? cfg.adapterId,
 			supportsNumericIds: cfg.supportsNumericIds ?? true,
+			supportsUUIDs: cfg.supportsUUIDs ?? false,
 			transaction: cfg.transaction ?? false,
 			disableTransformInput: cfg.disableTransformInput ?? false,
 			disableTransformOutput: cfg.disableTransformOutput ?? false,
@@ -257,8 +258,22 @@ export const createAdapterFactory =
 			const useNumberId =
 				options.advanced?.database?.useNumberId ||
 				options.advanced?.database?.generateId === "serial";
-			const shouldGenerateId =
-				!config.disableIdGeneration && !useNumberId && !forceAllowId;
+			const useUUIDs = options.advanced?.database?.generateId === "uuid";
+
+			let shouldGenerateId: boolean = (() => {
+				if (config.disableIdGeneration) {
+					return false;
+				} else if (useNumberId && !forceAllowId) {
+					// if force allow is true, then we should be using their custom provided id.
+					return false;
+				} else if (useUUIDs && !config.supportsUUIDs) {
+					// should only generate UUIDs via JS if the database doesn't support natively generating UUIDs.
+					return true;
+				} else {
+					return true;
+				}
+			})();
+
 			const model = getDefaultModelName(customModelName ?? "id");
 			return {
 				type: useNumberId ? "number" : "string",
@@ -280,16 +295,75 @@ export const createAdapterFactory =
 										model,
 									});
 								}
-								if (generateId === "uuid") {
-									return crypto.randomUUID();
-								}
 								if (config.customIdGenerator) {
 									return config.customIdGenerator({ model });
 								}
+								if (generateId === "uuid") {
+									return crypto.randomUUID();
+								}
 								return defaultGenerateId();
 							},
 						}
 					: {}),
+				transform: {
+					input: (value) => {
+						// Uncomment if need to debug id transformation
+						// console.log(`transforming id: `, {
+						// 	id: value,
+						// 	...(useNumberId ? { useNumberId } : {}),
+						// 	...(useUUIDs ? { useUUIDs } : {}),
+						// 	...(forceAllowId ? { forceAllowId } : {}),
+						// });
+						if (!value) return undefined;
+
+						if (useNumberId) {
+							const numberValue = Number(value);
+							// if invalid number, fallback to DB generated number id.
+							if (isNaN(numberValue)) {
+								return undefined;
+							}
+							return numberValue;
+						}
+
+						if (useUUIDs) {
+							// if it's generated by us, then we should return the value as is.
+							if (shouldGenerateId && !forceAllowId) return value;
+							if (config.disableIdGeneration) return undefined;
+							// if DB will handle UUID generation, then we should return undefined.
+							if (config.supportsUUIDs) return undefined;
+							// if forceAllowId is true, it means we should be using the ID provided during the adapter call.
+							if (forceAllowId && typeof value === "string") {
+								const uuidRegex =
+									/^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
+								if (uuidRegex.test(value)) {
+									return value;
+								} else {
+									const err = new Error();
+									const stack = err.stack
+										?.split("\n")
+										.filter((_, i) => i !== 1)
+										.join("\n")
+										.replace("Error:", "");
+									logger.warn(
+										"[Adapter Factory] - Invalid UUID value for field `id` provided when `forceAllowId` is true. Generating a new UUID.",
+										stack,
+									);
+								}
+							}
+							// if the value is not a string, and the database doesn't support generating it's own UUIDs, then we should be generating the UUID.
+							if (typeof value !== "string" && !config.supportsUUIDs) {
+								return crypto.randomUUID();
+							}
+							return undefined;
+						}
+
+						return value;
+					},
+					output: (value) => {
+						if (!value) return undefined;
+						return String(value);
+					},
+				},
 			} satisfies DBFieldAttribute;
 		};
 
@@ -325,15 +399,13 @@ export const createAdapterFactory =
 			const fields = schema[defaultModelName]!.fields;
 
 			const newMappedKeys = config.mapKeysTransformInput ?? {};
-			if (
-				!config.disableIdGeneration &&
-				!options.advanced?.database?.useNumberId
-			) {
-				fields.id = idField({
-					customModelName: defaultModelName,
-					forceAllowId: forceAllowId && "id" in data,
-				});
-			}
+			const useNumberId =
+				options.advanced?.database?.useNumberId ||
+				options.advanced?.database?.generateId === "serial";
+			fields.id = idField({
+				customModelName: defaultModelName,
+				forceAllowId: forceAllowId && "id" in data,
+			});
 			for (const field in fields) {
 				let value = data[field];
 				const fieldAttributes = fields[field];
@@ -378,10 +450,7 @@ export const createAdapterFactory =
 					newValue = await fieldAttributes!.transform.input(newValue);
 				}
 
-				if (
-					fieldAttributes!.references?.field === "id" &&
-					options.advanced?.database?.useNumberId
-				) {
+				if (fieldAttributes!.references?.field === "id" && useNumberId) {
 					if (Array.isArray(newValue)) {
 						newValue = newValue.map((x) => (x !== null ? Number(x) : null));
 					} else {
@@ -412,7 +481,7 @@ export const createAdapterFactory =
 						action,
 						field: newFieldName,
 						fieldAttributes: fieldAttributes!,
-						model: defaultModelName,
+						model: getModelName(defaultModelName),
 						schema,
 						options,
 					});
@@ -495,7 +564,7 @@ export const createAdapterFactory =
 							field: newFieldName,
 							fieldAttributes: field,
 							select,
-							model: unsafe_model,
+							model: getModelName(unsafe_model),
 							schema,
 							options,
 						});
@@ -549,11 +618,15 @@ export const createAdapterFactory =
 					model: defaultModelName,
 				});
 
+				const useNumberId =
+					options.advanced?.database?.useNumberId ||
+					options.advanced?.database?.generateId === "serial";
+
 				if (
 					defaultFieldName === "id" ||
 					fieldAttr!.references?.field === "id"
 				) {
-					if (options.advanced?.database?.useNumberId) {
+					if (useNumberId) {
 						if (Array.isArray(value)) {
 							newValue = value.map(Number);
 						} else {
@@ -649,7 +722,16 @@ export const createAdapterFactory =
 				let thisTransactionId = transactionId;
 				const model = getModelName(unsafeModel);
 				unsafeModel = getDefaultModelName(unsafeModel);
-				if ("id" in unsafeData && !forceAllowId) {
+				if (
+					"id" in unsafeData &&
+					typeof unsafeData.id !== "undefined" &&
+					!forceAllowId
+				) {
+					// The reason why `forceAllowId` was introduced was because we used to handle
+					// id generation ourselves (eg adapter.create({ data: { id: "123" } }))
+					// This was bad as certain things (such as number ids) would not work as expected.
+					// Since then, we have introduced the `forceAllowId` parameter to allow users to
+					// bypass this check. Otherwise, we would throw a warning stating that the id will be ignored
 					logger.warn(
 						`[${config.adapterName}] - You are trying to create a record with an id. This is not allowed as we handle id generation for you, unless you pass in the \`forceAllowId\` parameter. The id will be ignored.`,
 					);

packages/better-auth/src/adapters/adapter-factory/types.ts

@@ -19,9 +19,6 @@ export type AdapterFactoryOptions = {
 	adapter: AdapterFactoryCustomizeAdapterCreator;
 };
 
-/**
- * @deprecated Use `DBAdapterFactoryConfig` from `@better-auth/core/db/adapter` instead.
- */
 export interface AdapterFactoryConfig
 	extends Omit<DBAdapterFactoryConfig<BetterAuthOptions>, "transaction"> {
 	/**

packages/better-auth/src/adapters/create-test-suite.ts

@@ -119,6 +119,7 @@ export const createTestSuite = <
 		 */
 		alwaysMigrate?: boolean | undefined;
 		prefixTests?: string | undefined;
+		customIdGenerator?: () => any | Promise<any> | undefined;
 	},
 	tests: (
 		helpers: {
@@ -305,8 +306,18 @@ export const createTestSuite = <
 				return newData;
 			};
 
+			const idGenerator = async () => {
+				if (config.customIdGenerator) {
+					return config.customIdGenerator();
+				}
+				if (helpers.customIdGenerator) {
+					return helpers.customIdGenerator();
+				}
+				return generateId();
+			};
+
 			const generateModel: GenerateFn = async (model: string) => {
-				const id = (await helpers.customIdGenerator?.()) || generateId();
+				const id = await idGenerator();
 				const randomDate = new Date(
 					Date.now() - Math.random() * 1000 * 60 * 60 * 24 * 365,
 				);

packages/better-auth/src/adapters/drizzle-adapter/drizzle-adapter.ts

@@ -453,6 +453,7 @@ export const drizzleAdapter = (db: DB, config: DrizzleAdapterConfig) => {
 			adapterName: "Drizzle Adapter",
 			usePlural: config.usePlural ?? false,
 			debugLogs: config.debugLogs ?? false,
+			supportsUUIDs: config.provider === "pg" ? true : false,
 			transaction:
 				(config.transaction ?? false)
 					? (cb) =>

packages/better-auth/src/adapters/drizzle-adapter/test/adapter.drizzle.mysql.test.ts

@@ -8,6 +8,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { drizzleAdapter } from "../drizzle-adapter";
 import { generateDrizzleSchema, resetGenerationCount } from "./generate-schema";
@@ -65,6 +66,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite(),
 	],
 	async onFinish() {
 		await mysqlDB.end();

packages/better-auth/src/adapters/drizzle-adapter/test/adapter.drizzle.pg.test.ts

@@ -7,6 +7,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { drizzleAdapter } from "../drizzle-adapter";
 import { generateDrizzleSchema, resetGenerationCount } from "./generate-schema";
@@ -61,6 +62,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite(),
 	],
 	async onFinish() {
 		await cleanupDatabase(true);

packages/better-auth/src/adapters/drizzle-adapter/test/adapter.drizzle.sqlite.test.ts

@@ -9,6 +9,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { drizzleAdapter } from "../drizzle-adapter";
 import {
@@ -65,6 +66,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite(),
 	],
 	async onFinish() {
 		clearSchemaCache();

packages/better-auth/src/adapters/kysely-adapter/kysely-adapter.ts

@@ -335,6 +335,7 @@ export const kyselyAdapter = (
 					? false
 					: true,
 			supportsJSON: false,
+			supportsUUIDs: config?.type === "postgres" ? true : false,
 			transaction: config?.transaction
 				? (cb) =>
 						db.transaction().execute((trx) => {

packages/better-auth/src/adapters/kysely-adapter/test/adapter.kysely.mssql.test.ts

@@ -9,6 +9,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { kyselyAdapter } from "../kysely-adapter";
 
@@ -307,6 +308,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite({ showDB }),
 		numberIdTestSuite(),
+		uuidTestSuite(),
 	],
 	async onFinish() {
 		kyselyDB.destroy();

packages/better-auth/src/adapters/kysely-adapter/test/adapter.kysely.mysql.test.ts

@@ -8,6 +8,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { kyselyAdapter } from "../kysely-adapter";
 
@@ -47,6 +48,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite(),
 	],
 	async onFinish() {
 		await mysqlDB.end();

packages/better-auth/src/adapters/kysely-adapter/test/adapter.kysely.pg.test.ts

@@ -8,6 +8,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { kyselyAdapter } from "../kysely-adapter";
 
@@ -35,7 +36,8 @@ const { execute } = await testAdapter({
 		const opts = Object.assign(betterAuthOptions, {
 			database: pgDB,
 		} satisfies BetterAuthOptions);
-		const { runMigrations } = await getMigrations(opts);
+		const { runMigrations, compileMigrations } = await getMigrations(opts);
+		// console.log(await compileMigrations());
 		await runMigrations();
 	},
 	tests: [
@@ -43,6 +45,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite({}),
 	],
 	async onFinish() {
 		await pgDB.end();

packages/better-auth/src/adapters/kysely-adapter/test/adapter.kysely.sqlite.test.ts

@@ -9,6 +9,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { kyselyAdapter } from "../kysely-adapter";
 
@@ -45,6 +46,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite({}),
 	],
 	async onFinish() {
 		database.close();

packages/better-auth/src/adapters/memory-adapter/adapter.memory.test.ts

@@ -4,8 +4,8 @@ import {
 	authFlowTestSuite,
 	normalTestSuite,
 	numberIdTestSuite,
-	performanceTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../tests";
 import { memoryAdapter } from "./memory-adapter";
 
@@ -29,7 +29,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite({ disableTests: { ALL: true } }),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
-		performanceTestSuite(),
+		uuidTestSuite(),
 	],
 	async onFinish() {},
 });

packages/better-auth/src/adapters/memory-adapter/memory-adapter.ts

@@ -26,11 +26,10 @@ export const memoryAdapter = (
 			usePlural: false,
 			debugLogs: config?.debugLogs || false,
 			customTransformInput(props) {
-				if (
-					props.options.advanced?.database?.useNumberId &&
-					props.field === "id" &&
-					props.action === "create"
-				) {
+				const useNumberId =
+					props.options.advanced?.database?.useNumberId ||
+					props.options.advanced?.database?.generateId === "serial";
+				if (useNumberId && props.field === "id" && props.action === "create") {
 					return db[props.model]!.length + 1;
 				}
 				return props.data;
@@ -49,7 +48,7 @@ export const memoryAdapter = (
 				}
 			},
 		},
-		adapter: ({ getFieldName, options, debugLog }) => {
+		adapter: ({ getFieldName, options, debugLog, getModelName }) => {
 			function convertWhereClause(where: CleanedWhere[], model: string) {
 				const table = db[model];
 				if (!table) {
@@ -117,9 +116,12 @@ export const memoryAdapter = (
 			}
 			return {
 				create: async ({ model, data }) => {
-					if (options.advanced?.database?.useNumberId) {
+					const useNumberId =
+						options.advanced?.database?.useNumberId ||
+						options.advanced?.database?.generateId === "serial";
+					if (useNumberId) {
 						// @ts-expect-error
-						data.id = db[model]!.length + 1;
+						data.id = db[getModelName(model)]!.length + 1;
 					}
 					if (!db[model]) {
 						db[model] = [];

packages/better-auth/src/adapters/mongodb-adapter/adapter.mongo-db.test.ts

@@ -30,7 +30,8 @@ const { execute } = await testAdapter({
 		normalTestSuite(),
 		authFlowTestSuite(),
 		transactionsTestSuite(),
-		// numberIdTestSuite(), // Mongo doesn't support number ids
+		// numberIdTestSuite(), // no support
+		// uuidTestSuite() // no support
 	],
 	customIdGenerator: () => new ObjectId().toHexString(),
 });

packages/better-auth/src/adapters/prisma-adapter/prisma-adapter.ts

@@ -264,6 +264,7 @@ export const prismaAdapter = (prisma: PrismaClient, config: PrismaConfig) => {
 			adapterName: "Prisma Adapter",
 			usePlural: config.usePlural ?? false,
 			debugLogs: config.debugLogs ?? false,
+			supportsUUIDs: config.provider === "postgresql" ? true : false,
 			transaction:
 				(config.transaction ?? false)
 					? (cb) =>

packages/better-auth/src/adapters/prisma-adapter/test/prisma.mysql.test.ts

@@ -6,6 +6,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { prismaAdapter } from "../prisma-adapter";
 import { generateAuthConfigFile } from "./generate-auth-config";
@@ -46,6 +47,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite(),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite(),
 	],
 	onFinish: async () => {},
 	prefixTests: dialect,

packages/better-auth/src/adapters/prisma-adapter/test/prisma.pg.test.ts

@@ -6,6 +6,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { prismaAdapter } from "../prisma-adapter";
 import { generateAuthConfigFile } from "./generate-auth-config";
@@ -44,6 +45,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite(),
 		authFlowTestSuite(),
 		numberIdTestSuite(),
+		uuidTestSuite({}),
 	],
 	onFinish: async () => {},
 	prefixTests: "pg",

packages/better-auth/src/adapters/prisma-adapter/test/prisma.sqlite.test.ts

@@ -7,6 +7,7 @@ import {
 	normalTestSuite,
 	numberIdTestSuite,
 	transactionsTestSuite,
+	uuidTestSuite,
 } from "../../tests";
 import { prismaAdapter } from "../prisma-adapter";
 import { generateAuthConfigFile } from "./generate-auth-config";
@@ -47,6 +48,7 @@ const { execute } = await testAdapter({
 		transactionsTestSuite(),
 		authFlowTestSuite(),
 		numberIdTestSuite({}),
+		uuidTestSuite(),
 	],
 	onFinish: async () => {},
 	prefixTests: dialect,

packages/better-auth/src/adapters/test.ts

@@ -1069,7 +1069,7 @@ export function runNumberIdAdapterTest(opts: NumberIdAdapterTestOptions) {
 		await opts.getAdapter({
 			advanced: {
 				database: {
-					useNumberId: true,
+					generateId: "serial",
 				},
 			},
 		});
@@ -1151,7 +1151,7 @@ export function runNumberIdAdapterTest(opts: NumberIdAdapterTestOptions) {
 				predefinedOptions: {
 					advanced: {
 						database: {
-							useNumberId: true,
+							generateId: "serial",
 						},
 					},
 				},

packages/better-auth/src/adapters/tests/index.ts

@@ -3,3 +3,4 @@ export * from "./normal";
 export * from "./number-id";
 export * from "./performance";
 export * from "./transactions";
+export * from "./uuid";

packages/better-auth/src/adapters/tests/normal.ts

@@ -11,7 +11,10 @@ export const normalTestSuite = createTestSuite("normal", {}, (helpers) => {
 	return {
 		"init - tests": async () => {
 			const opts = helpers.getBetterAuthOptions();
-			expect(opts.advanced?.database?.useNumberId).toBe(undefined);
+			expect(
+				!opts.advanced?.database?.useNumberId &&
+					opts.advanced?.database?.generateId !== "serial",
+			).toBeTruthy();
 		},
 		...tests,
 	};
@@ -37,12 +40,15 @@ export const getNormalTestSuiteTests = ({
 				forceAllowId: true,
 			});
 			const options = getBetterAuthOptions();
-			if (options.advanced?.database?.useNumberId) {
-				expect(typeof result.id).toEqual("string");
+			if (
+				options.advanced?.database?.useNumberId ||
+				options.advanced?.database?.generateId === "serial" ||
+				options.advanced?.database?.generateId === "uuid"
+			) {
 				user.id = result.id;
-			} else {
-				expect(typeof result.id).toEqual("string");
 			}
+
+			expect(typeof result.id).toEqual("string");
 			const transformed = transformGeneratedModel(user);
 			// console.log(`pre-transformed:`, user);
 			// console.log(`transformed:`, transformed);
@@ -295,9 +301,13 @@ export const getNormalTestSuiteTests = ({
 			expect(result).toEqual(session);
 		},
 		"findOne - should not throw on record not found": async () => {
+			const options = getBetterAuthOptions();
+			const useUUIDs = options.advanced?.database?.generateId === "uuid";
 			const result = await adapter.findOne<User>({
 				model: "user",
-				where: [{ field: "id", value: "100000" }],
+				where: [
+					{ field: "id", value: useUUIDs ? crypto.randomUUID() : "100000" },
+				],
 			});
 			expect(result).toBeNull();
 		},
@@ -422,9 +432,13 @@ export const getNormalTestSuiteTests = ({
 		},
 		"findMany - should return an empty array when no models are found":
 			async () => {
+				const options = getBetterAuthOptions();
+				const useUUIDs = options.advanced?.database?.generateId === "uuid";
 				const result = await adapter.findMany<User>({
 					model: "user",
-					where: [{ field: "id", value: "100000" }],
+					where: [
+						{ field: "id", value: useUUIDs ? crypto.randomUUID() : "100000" },
+					],
 				});
 				expect(result).toEqual([]);
 			},
@@ -859,7 +873,10 @@ export const getNormalTestSuiteTests = ({
 				throw error;
 			}
 			const options = getBetterAuthOptions();
-			if (options.advanced?.database?.useNumberId) {
+			if (
+				options.advanced?.database?.useNumberId ||
+				options.advanced?.database?.generateId === "serial"
+			) {
 				expect(Number(users[0]!.id)).not.toBeNaN();
 			}
 		},
@@ -1166,10 +1183,14 @@ export const getNormalTestSuiteTests = ({
 			expect(result).toBeNull();
 		},
 		"delete - should not throw on record not found": async () => {
+			const options = getBetterAuthOptions();
+			const useUUIDs = options.advanced?.database?.generateId === "uuid";
 			await expect(
 				adapter.delete({
 					model: "user",
-					where: [{ field: "id", value: "100000" }],
+					where: [
+						{ field: "id", value: useUUIDs ? crypto.randomUUID() : "100000" },
+					],
 				}),
 			).resolves.not.toThrow();
 		},

packages/better-auth/src/adapters/tests/number-id.ts

@@ -9,7 +9,7 @@ export const numberIdTestSuite = createTestSuite(
 		defaultBetterAuthOptions: {
 			advanced: {
 				database: {
-					useNumberId: true,
+					generateId: "serial",
 				},
 			},
 		},
@@ -23,7 +23,10 @@ export const numberIdTestSuite = createTestSuite(
 		return {
 			"init - tests": async () => {
 				const opts = helpers.getBetterAuthOptions();
-				expect(opts.advanced?.database?.useNumberId).toBe(true);
+				expect(
+					opts.advanced?.database?.useNumberId ||
+						opts.advanced?.database?.generateId === "serial",
+				).toBe(true);
 			},
 			"create - should return a number id": async () => {
 				const user = await helpers.generate("user");

packages/better-auth/src/adapters/tests/uuid.ts

@@ -0,0 +1,68 @@
+import { expect } from "vitest";
+import type { User } from "../../../../core/src/db/schema/user";
+import { createTestSuite } from "../create-test-suite";
+import { getNormalTestSuiteTests } from "./normal";
+
+export const uuidTestSuite = createTestSuite(
+	"uuid",
+	{
+		defaultBetterAuthOptions: {
+			advanced: {
+				database: {
+					generateId: "uuid",
+				},
+			},
+		},
+		prefixTests: "uuid",
+		alwaysMigrate: true,
+		// This is here to overwrite `generateId` functions to generate UUIDs instead of the default.
+		// Since existing tests often use generated IDs as well as `forceAllowId` to be true, this is needed to ensure the tests pass.
+		customIdGenerator() {
+			return crypto.randomUUID();
+		},
+	},
+	(helpers) => {
+		const { "create - should use generateId if provided": _, ...normalTests } =
+			getNormalTestSuiteTests(helpers);
+		return {
+			"init - tests": async () => {
+				const opts = helpers.getBetterAuthOptions();
+				expect(opts.advanced?.database?.generateId === "uuid").toBe(true);
+			},
+			"create - should return a uuid": async () => {
+				const user = await helpers.generate("user");
+				const res = await helpers.adapter.create<User>({
+					model: "user",
+					data: {
+						...user,
+						//@ts-expect-error - remove id from `user`
+						id: undefined,
+					},
+				});
+				expect(res).toHaveProperty("id");
+				expect(typeof res.id).toBe("string");
+				const uuidRegex =
+					/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+				expect(res.id).toMatch(uuidRegex);
+				console.log(res);
+			},
+			"findOne - should find a model using a uuid": async () => {
+				const { id: _, ...user } = await helpers.generate("user");
+				const res = await helpers.adapter.create<User>({
+					model: "user",
+					data: user,
+				});
+
+				const result = await helpers.adapter.findOne<User>({
+					model: "user",
+					where: [{ field: "id", value: res.id }],
+				});
+				const uuidRegex =
+					/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+				expect(result?.id).toMatch(uuidRegex);
+				expect(result).toEqual(res);
+			},
+			...normalTests,
+		};
+	},
+);

packages/better-auth/src/db/get-migration-schema.test.ts

@@ -213,8 +213,10 @@ describe.runIf(isPostgresAvailable)(
 					},
 				},
 			};
-			const { runMigrations } = await getMigrations(config);
+			const { runMigrations, compileMigrations } = await getMigrations(config);
 			await runMigrations();
+			const migrations = await compileMigrations();
+			console.log(migrations);
 			const auth = betterAuth(config);
 
 			const user = await auth.api.signUpEmail({
@@ -227,6 +229,12 @@ describe.runIf(isPostgresAvailable)(
 			const uuidRegex =
 				/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
 			expect(user.user.id).toMatch(uuidRegex);
+
+			// run migrations again to ensure no migrations are needed & no errors are thrown
+			const { compileMigrations: round2Migrations } =
+				await getMigrations(config);
+			const secondRoundOfMigrations = await round2Migrations();
+			expect(secondRoundOfMigrations).toEqual(";");
 		});
 	},
 );

packages/better-auth/src/db/get-migration.ts

@@ -317,15 +317,30 @@ export async function getMigrations(config: BetterAuthOptions) {
 			},
 			id: {
 				postgres: useNumberId ? "serial" : useUUIDs ? "uuid" : "text",
-				mysql: useNumberId ? "integer" : useUUIDs ? "uuid" : "varchar(36)",
-				mssql: useNumberId ? "integer" : useUUIDs ? "uuid" : "varchar(36)",
-
+				mysql: useNumberId
+					? "integer"
+					: useUUIDs
+						? "varchar(36)"
+						: "varchar(36)",
+				mssql: useNumberId
+					? "integer"
+					: useUUIDs
+						? "varchar(36)"
+						: "varchar(36)",
 				sqlite: useNumberId ? "integer" : "text",
 			},
 			foreignKeyId: {
 				postgres: useNumberId ? "integer" : useUUIDs ? "uuid" : "text",
-				mysql: useNumberId ? "integer" : useUUIDs ? "uuid" : "varchar(36)",
-				mssql: useNumberId ? "integer" : useUUIDs ? "uuid" : "varchar(36)",
+				mysql: useNumberId
+					? "integer"
+					: useUUIDs
+						? "varchar(36)"
+						: "varchar(36)",
+				mssql: useNumberId
+					? "integer"
+					: useUUIDs
+						? "varchar(36)" /* Should be using `UNIQUEIDENTIFIER` but Kysely doesn't support it */
+						: "varchar(36)",
 				sqlite: useNumberId ? "integer" : "text",
 			},
 		} as const;
@@ -399,21 +414,10 @@ export async function getMigrations(config: BetterAuthOptions) {
 
 	if (toBeCreated.length) {
 		for (const table of toBeCreated) {
-			let dbT = db.schema.createTable(table.table).addColumn(
-				"id",
-				useNumberId
-					? dbType === "postgres"
-						? "serial"
-						: "integer"
-					: useUUIDs
-						? dbType === "postgres" || dbType === "mysql" || dbType === "mssql"
-							? "uuid"
-							: "text"
-						: dbType === "mysql" || dbType === "mssql"
-							? "varchar(36)"
-							: "text",
-
-				(col) => {
+			const idType = getType({ type: useNumberId ? "number" : "string" }, "id");
+			let dbT = db.schema
+				.createTable(table.table)
+				.addColumn("id", idType, (col) => {
 					if (useNumberId) {
 						if (dbType === "postgres" || dbType === "sqlite") {
 							return col.primaryKey().notNull();
@@ -428,14 +432,11 @@ export async function getMigrations(config: BetterAuthOptions) {
 								.primaryKey()
 								.defaultTo(sql`pg_catalog.gen_random_uuid()`)
 								.notNull();
-						} else if (dbType === "mysql" || dbType === "mssql") {
-							return col.primaryKey().defaultTo(sql`uuid()`).notNull();
 						}
 						return col.primaryKey().notNull();
 					}
 					return col.primaryKey().notNull();
-				},
-			);
+				});
 
 			for (const [fieldName, field] of Object.entries(table.fields)) {
 				const type = getType(field, fieldName);

packages/cli/src/generators/drizzle.ts

@@ -52,7 +52,11 @@ export const generateDrizzleSchema: SchemaGenerator = async ({
 			}
 			name = convertToSnakeCase(name, adapter.options?.camelCase);
 			if (field.references?.field === "id") {
-				if (options.advanced?.database?.useNumberId) {
+				const useNumberId =
+					options.advanced?.database?.useNumberId ||
+					options.advanced?.database?.generateId === "serial";
+				const useUUIDs = options.advanced?.database?.generateId === "uuid";
+				if (useNumberId) {
 					if (databaseType === "pg") {
 						return `integer('${name}')`;
 					} else if (databaseType === "mysql") {
@@ -62,6 +66,9 @@ export const generateDrizzleSchema: SchemaGenerator = async ({
 						return `integer('${name}')`;
 					}
 				}
+				if (useUUIDs && databaseType === "pg") {
+					return `uuid('${name}')`;
+				}
 				if (field.references.field) {
 					if (databaseType === "mysql") {
 						return `varchar('${name}', { length: 36 })`;
@@ -144,7 +151,14 @@ export const generateDrizzleSchema: SchemaGenerator = async ({
 
 		let id: string = "";
 
-		if (options.advanced?.database?.useNumberId) {
+		const useNumberId =
+			options.advanced?.database?.useNumberId ||
+			options.advanced?.database?.generateId === "serial";
+		const useUUIDs = options.advanced?.database?.generateId === "uuid";
+
+		if (useUUIDs && databaseType === "pg") {
+			id = `uuid("id").default(sql\`pg_catalog.gen_random_uuid()\`).primaryKey()`;
+		} else if (useNumberId) {
 			if (databaseType === "pg") {
 				id = `serial("id").primaryKey()`;
 			} else if (databaseType === "sqlite") {
@@ -289,7 +303,11 @@ function generateImport({
 		if (hasJson && hasBigint) break;
 	}
 
-	const useNumberId = options.advanced?.database?.useNumberId;
+	const useNumberId =
+		options.advanced?.database?.useNumberId ||
+		options.advanced?.database?.generateId === "serial";
+
+	const useUUIDs = options.advanced?.database?.generateId === "uuid";
 
 	coreImports.push(`${databaseType}Table`);
 	coreImports.push(
@@ -328,6 +346,10 @@ function generateImport({
 			coreImports.push("mysqlEnum");
 		}
 	} else if (databaseType === "pg") {
+		if (useUUIDs) {
+			rootImports.push("sql");
+		}
+
 		// Only include integer for PG if actually needed
 		const hasNonBigintNumber = Object.values(tables).some((table) =>
 			Object.values(table.fields).some(
@@ -344,14 +366,22 @@ function generateImport({
 		// handles the references field with useNumberId
 		const needsInteger =
 			hasNonBigintNumber ||
-			(options.advanced?.database?.useNumberId && hasFkToId);
+			((options.advanced?.database?.useNumberId ||
+				options.advanced?.database?.generateId === "serial") &&
+				hasFkToId);
 		if (needsInteger) {
 			coreImports.push("integer");
 		}
 	} else {
 		coreImports.push("integer");
 	}
-	coreImports.push(useNumberId ? (databaseType === "pg" ? "serial" : "") : "");
+	if (databaseType === "pg") {
+		if (useNumberId) {
+			coreImports.push("serial");
+		} else if (useUUIDs) {
+			coreImports.push("uuid");
+		}
+	}
 
 	//handle json last on the import order
 	if (hasJson) {

packages/cli/src/generators/prisma.ts

@@ -124,12 +124,25 @@ export const generatePrismaSchema: SchemaGenerator = async ({
 						.attribute("id")
 						.attribute(`map("_id")`);
 				} else {
-					if (options.advanced?.database?.useNumberId) {
+					const useNumberId =
+						options.advanced?.database?.useNumberId ||
+						options.advanced?.database?.generateId === "serial";
+					const useUUIDs = options.advanced?.database?.generateId === "uuid";
+					if (useNumberId) {
 						builder
 							.model(modelName)
 							.field("id", "Int")
 							.attribute("id")
 							.attribute("default(autoincrement())");
+					} else if (useUUIDs && provider === "postgresql") {
+						builder
+							.model(modelName)
+							.field("id", "String")
+							.attribute("id")
+							.attribute("db.Uuid")
+							.attribute(
+								'default(dbgenerated("pg_catalog.gen_random_uuid()"))',
+							);
 					} else {
 						builder.model(modelName).field("id", "String").attribute("id");
 					}
@@ -149,10 +162,13 @@ export const generatePrismaSchema: SchemaGenerator = async ({
 						continue;
 					}
 				}
-
+				const useUUIDs = options.advanced?.database?.generateId === "uuid";
+				const useNumberId =
+					options.advanced?.database?.useNumberId ||
+					options.advanced?.database?.generateId === "serial";
 				const fieldBuilder = builder.model(modelName).field(
 					fieldName,
-					field === "id" && options.advanced?.database?.useNumberId
+					field === "id" && useNumberId
 						? getType({
 								isBigint: false,
 								isOptional: false,
@@ -163,7 +179,7 @@ export const generatePrismaSchema: SchemaGenerator = async ({
 								isOptional: !attr?.required,
 								type:
 									attr.references?.field === "id"
-										? options.advanced?.database?.useNumberId
+										? useNumberId
 											? "number"
 											: "string"
 										: attr.type,
@@ -202,6 +218,10 @@ export const generatePrismaSchema: SchemaGenerator = async ({
 				}
 
 				if (attr.references) {
+					if (useUUIDs && provider === "postgresql") {
+						fieldBuilder.attribute(`db.Uuid`);
+					}
+
 					const referencedOriginalModelName = attr.references.model;
 					const referencedCustomModelName =
 						tables[referencedOriginalModelName]?.modelName ||
@@ -212,17 +232,17 @@ export const generatePrismaSchema: SchemaGenerator = async ({
 					else if (attr.references.onDelete === "set default")
 						action = "SetDefault";
 					else if (attr.references.onDelete === "restrict") action = "Restrict";
+
+					const relationField = `relation(fields: [${fieldName}], references: [${attr.references.field}], onDelete: ${action})`;
 					builder
 						.model(modelName)
 						.field(
-							`${referencedCustomModelName.toLowerCase()}`,
+							referencedCustomModelName.toLowerCase(),
 							`${capitalizeFirstLetter(referencedCustomModelName)}${
 								!attr.required ? "?" : ""
 							}`,
 						)
-						.attribute(
-							`relation(fields: [${fieldName}], references: [${attr.references.field}], onDelete: ${action})`,
-						);
+						.attribute(relationField);
 				}
 				if (
 					!attr.unique &&
@@ -258,10 +278,11 @@ export const generatePrismaSchema: SchemaGenerator = async ({
 
 					let indexField = fieldName;
 					if (provider === "mysql" && field && field.type === "string") {
-						if (
-							field.references?.field === "id" &&
-							options.advanced?.database?.useNumberId
-						) {
+						const useNumberId =
+							options.advanced?.database?.useNumberId ||
+							options.advanced?.database?.generateId === "serial";
+						const useUUIDs = options.advanced?.database?.generateId === "uuid";
+						if (field.references?.field === "id" && (useNumberId || useUUIDs)) {
 							indexField = `${fieldName}`;
 						} else {
 							indexField = `${fieldName}(length: 191)`; // length of 191 because String in Prisma is varchar(191)

packages/cli/test/__snapshots__/auth-schema-mysql-uuid.txt

@@ -0,0 +1,99 @@
+import {
+  mysqlTable,
+  varchar,
+  text,
+  timestamp,
+  boolean,
+  index,
+} from "drizzle-orm/mysql-core";
+
+export const custom_user = mysqlTable("custom_user", {
+  id: varchar("id", { length: 36 }).primaryKey(),
+  name: varchar("name", { length: 255 }).notNull(),
+  email: varchar("email", { length: 255 }).notNull().unique(),
+  emailVerified: boolean("email_verified").default(false).notNull(),
+  image: text("image"),
+  createdAt: timestamp("created_at", { fsp: 3 }).defaultNow().notNull(),
+  updatedAt: timestamp("updated_at", { fsp: 3 })
+    .defaultNow()
+    .$onUpdate(() => /* @__PURE__ */ new Date())
+    .notNull(),
+  twoFactorEnabled: boolean("two_factor_enabled").default(false),
+  username: varchar("username", { length: 255 }).unique(),
+  displayUsername: text("display_username"),
+});
+
+export const custom_session = mysqlTable(
+  "custom_session",
+  {
+    id: varchar("id", { length: 36 }).primaryKey(),
+    expiresAt: timestamp("expires_at", { fsp: 3 }).notNull(),
+    token: varchar("token", { length: 255 }).notNull().unique(),
+    createdAt: timestamp("created_at", { fsp: 3 }).defaultNow().notNull(),
+    updatedAt: timestamp("updated_at", { fsp: 3 })
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+    ipAddress: text("ip_address"),
+    userAgent: text("user_agent"),
+    userId: varchar("user_id", { length: 36 })
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+  },
+  (table) => [index("custom_session_userId_idx").on(table.userId)],
+);
+
+export const custom_account = mysqlTable(
+  "custom_account",
+  {
+    id: varchar("id", { length: 36 }).primaryKey(),
+    accountId: text("account_id").notNull(),
+    providerId: text("provider_id").notNull(),
+    userId: varchar("user_id", { length: 36 })
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+    accessToken: text("access_token"),
+    refreshToken: text("refresh_token"),
+    idToken: text("id_token"),
+    accessTokenExpiresAt: timestamp("access_token_expires_at", { fsp: 3 }),
+    refreshTokenExpiresAt: timestamp("refresh_token_expires_at", { fsp: 3 }),
+    scope: text("scope"),
+    password: text("password"),
+    createdAt: timestamp("created_at", { fsp: 3 }).defaultNow().notNull(),
+    updatedAt: timestamp("updated_at", { fsp: 3 })
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+  },
+  (table) => [index("custom_account_userId_idx").on(table.userId)],
+);
+
+export const custom_verification = mysqlTable(
+  "custom_verification",
+  {
+    id: varchar("id", { length: 36 }).primaryKey(),
+    identifier: varchar("identifier", { length: 255 }).notNull(),
+    value: text("value").notNull(),
+    expiresAt: timestamp("expires_at", { fsp: 3 }).notNull(),
+    createdAt: timestamp("created_at", { fsp: 3 }).defaultNow().notNull(),
+    updatedAt: timestamp("updated_at", { fsp: 3 })
+      .defaultNow()
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+  },
+  (table) => [index("custom_verification_identifier_idx").on(table.identifier)],
+);
+
+export const twoFactor = mysqlTable(
+  "two_factor",
+  {
+    id: varchar("id", { length: 36 }).primaryKey(),
+    secret: varchar("secret", { length: 255 }).notNull(),
+    backupCodes: text("backup_codes").notNull(),
+    userId: varchar("user_id", { length: 36 })
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+  },
+  (table) => [
+    index("twoFactor_secret_idx").on(table.secret),
+    index("twoFactor_userId_idx").on(table.userId),
+  ],
+);

packages/cli/test/__snapshots__/auth-schema-pg-uuid.txt

@@ -0,0 +1,110 @@
+import { sql } from "drizzle-orm";
+import {
+  pgTable,
+  text,
+  timestamp,
+  boolean,
+  uuid,
+  index,
+} from "drizzle-orm/pg-core";
+
+export const custom_user = pgTable("custom_user", {
+  id: uuid("id")
+    .default(sql`pg_catalog.gen_random_uuid()`)
+    .primaryKey(),
+  name: text("name").notNull(),
+  email: text("email").notNull().unique(),
+  emailVerified: boolean("email_verified").default(false).notNull(),
+  image: text("image"),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at")
+    .defaultNow()
+    .$onUpdate(() => /* @__PURE__ */ new Date())
+    .notNull(),
+  twoFactorEnabled: boolean("two_factor_enabled").default(false),
+  username: text("username").unique(),
+  displayUsername: text("display_username"),
+});
+
+export const custom_session = pgTable(
+  "custom_session",
+  {
+    id: uuid("id")
+      .default(sql`pg_catalog.gen_random_uuid()`)
+      .primaryKey(),
+    expiresAt: timestamp("expires_at").notNull(),
+    token: text("token").notNull().unique(),
+    createdAt: timestamp("created_at").defaultNow().notNull(),
+    updatedAt: timestamp("updated_at")
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+    ipAddress: text("ip_address"),
+    userAgent: text("user_agent"),
+    userId: uuid("user_id")
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+  },
+  (table) => [index("custom_session_userId_idx").on(table.userId)],
+);
+
+export const custom_account = pgTable(
+  "custom_account",
+  {
+    id: uuid("id")
+      .default(sql`pg_catalog.gen_random_uuid()`)
+      .primaryKey(),
+    accountId: text("account_id").notNull(),
+    providerId: text("provider_id").notNull(),
+    userId: uuid("user_id")
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+    accessToken: text("access_token"),
+    refreshToken: text("refresh_token"),
+    idToken: text("id_token"),
+    accessTokenExpiresAt: timestamp("access_token_expires_at"),
+    refreshTokenExpiresAt: timestamp("refresh_token_expires_at"),
+    scope: text("scope"),
+    password: text("password"),
+    createdAt: timestamp("created_at").defaultNow().notNull(),
+    updatedAt: timestamp("updated_at")
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+  },
+  (table) => [index("custom_account_userId_idx").on(table.userId)],
+);
+
+export const custom_verification = pgTable(
+  "custom_verification",
+  {
+    id: uuid("id")
+      .default(sql`pg_catalog.gen_random_uuid()`)
+      .primaryKey(),
+    identifier: text("identifier").notNull(),
+    value: text("value").notNull(),
+    expiresAt: timestamp("expires_at").notNull(),
+    createdAt: timestamp("created_at").defaultNow().notNull(),
+    updatedAt: timestamp("updated_at")
+      .defaultNow()
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+  },
+  (table) => [index("custom_verification_identifier_idx").on(table.identifier)],
+);
+
+export const twoFactor = pgTable(
+  "two_factor",
+  {
+    id: uuid("id")
+      .default(sql`pg_catalog.gen_random_uuid()`)
+      .primaryKey(),
+    secret: text("secret").notNull(),
+    backupCodes: text("backup_codes").notNull(),
+    userId: uuid("user_id")
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+  },
+  (table) => [
+    index("twoFactor_secret_idx").on(table.secret),
+    index("twoFactor_userId_idx").on(table.userId),
+  ],
+);

packages/cli/test/__snapshots__/auth-schema-sqlite-uuid.txt

@@ -0,0 +1,109 @@
+import { sql } from "drizzle-orm";
+import { sqliteTable, text, integer, index } from "drizzle-orm/sqlite-core";
+
+export const custom_user = sqliteTable("custom_user", {
+  id: text("id").primaryKey(),
+  name: text("name").notNull(),
+  email: text("email").notNull().unique(),
+  emailVerified: integer("email_verified", { mode: "boolean" })
+    .default(false)
+    .notNull(),
+  image: text("image"),
+  createdAt: integer("created_at", { mode: "timestamp_ms" })
+    .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
+    .notNull(),
+  updatedAt: integer("updated_at", { mode: "timestamp_ms" })
+    .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
+    .$onUpdate(() => /* @__PURE__ */ new Date())
+    .notNull(),
+  twoFactorEnabled: integer("two_factor_enabled", { mode: "boolean" }).default(
+    false,
+  ),
+  username: text("username").unique(),
+  displayUsername: text("display_username"),
+});
+
+export const custom_session = sqliteTable(
+  "custom_session",
+  {
+    id: text("id").primaryKey(),
+    expiresAt: integer("expires_at", { mode: "timestamp_ms" }).notNull(),
+    token: text("token").notNull().unique(),
+    createdAt: integer("created_at", { mode: "timestamp_ms" })
+      .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
+      .notNull(),
+    updatedAt: integer("updated_at", { mode: "timestamp_ms" })
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+    ipAddress: text("ip_address"),
+    userAgent: text("user_agent"),
+    userId: text("user_id")
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+  },
+  (table) => [index("custom_session_userId_idx").on(table.userId)],
+);
+
+export const custom_account = sqliteTable(
+  "custom_account",
+  {
+    id: text("id").primaryKey(),
+    accountId: text("account_id").notNull(),
+    providerId: text("provider_id").notNull(),
+    userId: text("user_id")
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+    accessToken: text("access_token"),
+    refreshToken: text("refresh_token"),
+    idToken: text("id_token"),
+    accessTokenExpiresAt: integer("access_token_expires_at", {
+      mode: "timestamp_ms",
+    }),
+    refreshTokenExpiresAt: integer("refresh_token_expires_at", {
+      mode: "timestamp_ms",
+    }),
+    scope: text("scope"),
+    password: text("password"),
+    createdAt: integer("created_at", { mode: "timestamp_ms" })
+      .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
+      .notNull(),
+    updatedAt: integer("updated_at", { mode: "timestamp_ms" })
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+  },
+  (table) => [index("custom_account_userId_idx").on(table.userId)],
+);
+
+export const custom_verification = sqliteTable(
+  "custom_verification",
+  {
+    id: text("id").primaryKey(),
+    identifier: text("identifier").notNull(),
+    value: text("value").notNull(),
+    expiresAt: integer("expires_at", { mode: "timestamp_ms" }).notNull(),
+    createdAt: integer("created_at", { mode: "timestamp_ms" })
+      .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
+      .notNull(),
+    updatedAt: integer("updated_at", { mode: "timestamp_ms" })
+      .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
+      .$onUpdate(() => /* @__PURE__ */ new Date())
+      .notNull(),
+  },
+  (table) => [index("custom_verification_identifier_idx").on(table.identifier)],
+);
+
+export const twoFactor = sqliteTable(
+  "two_factor",
+  {
+    id: text("id").primaryKey(),
+    secret: text("secret").notNull(),
+    backupCodes: text("backup_codes").notNull(),
+    userId: text("user_id")
+      .notNull()
+      .references(() => custom_user.id, { onDelete: "cascade" }),
+  },
+  (table) => [
+    index("twoFactor_secret_idx").on(table.secret),
+    index("twoFactor_userId_idx").on(table.userId),
+  ],
+);

packages/cli/test/__snapshots__/schema-uuid.prisma

@@ -0,0 +1,89 @@
+
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+  url      = env("DATABASE_URL")
+}
+
+model User {
+  id               String      @id @db.Uuid @default(dbgenerated("pg_catalog.gen_random_uuid()"))
+  name             String
+  email            String
+  emailVerified    Boolean     @default(false)
+  image            String?
+  createdAt        DateTime    @default(now())
+  updatedAt        DateTime    @updatedAt
+  twoFactorEnabled Boolean?    @default(false)
+  username         String?
+  displayUsername  String?
+  sessions         Session[]
+  accounts         Account[]
+  twofactors       TwoFactor[]
+
+  @@unique([email])
+  @@unique([username])
+  @@map("user")
+}
+
+model Session {
+  id        String   @id @db.Uuid @default(dbgenerated("pg_catalog.gen_random_uuid()"))
+  expiresAt DateTime
+  token     String
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+  ipAddress String?
+  userAgent String?
+  userId    String   @db.Uuid
+  user      User     @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@unique([token])
+  @@index([userId])
+  @@map("session")
+}
+
+model Account {
+  id                    String    @id @db.Uuid @default(dbgenerated("pg_catalog.gen_random_uuid()"))
+  accountId             String
+  providerId            String
+  userId                String    @db.Uuid
+  user                  User      @relation(fields: [userId], references: [id], onDelete: Cascade)
+  accessToken           String?
+  refreshToken          String?
+  idToken               String?
+  accessTokenExpiresAt  DateTime?
+  refreshTokenExpiresAt DateTime?
+  scope                 String?
+  password              String?
+  createdAt             DateTime  @default(now())
+  updatedAt             DateTime  @updatedAt
+
+  @@index([userId])
+  @@map("account")
+}
+
+model Verification {
+  id         String   @id @db.Uuid @default(dbgenerated("pg_catalog.gen_random_uuid()"))
+  identifier String
+  value      String
+  expiresAt  DateTime
+  createdAt  DateTime @default(now())
+  updatedAt  DateTime @updatedAt
+
+  @@index([identifier])
+  @@map("verification")
+}
+
+model TwoFactor {
+  id          String @id @db.Uuid @default(dbgenerated("pg_catalog.gen_random_uuid()"))
+  secret      String
+  backupCodes String
+  userId      String @db.Uuid
+  user        User   @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@index([secret])
+  @@index([userId])
+  @@map("twoFactor")
+}

packages/cli/test/generate-all-db.test.ts

@@ -103,7 +103,7 @@ describe("generate drizzle schema for all databases", async () => {
 				plugins: [twoFactor(), username()],
 				advanced: {
 					database: {
-						useNumberId: true,
+						generateId: "serial",
 					},
 				},
 				user: {
@@ -124,6 +124,133 @@ describe("generate drizzle schema for all databases", async () => {
 			"./__snapshots__/auth-schema-mysql-number-id.txt",
 		);
 	});
+	it("should generate drizzle schema for MySQL with uuid id", async () => {
+		const schema = await generateDrizzleSchema({
+			file: "test.drizzle",
+			adapter: drizzleAdapter(
+				{},
+				{
+					provider: "mysql",
+					schema: {},
+				},
+			)({} as BetterAuthOptions),
+			options: {
+				database: drizzleAdapter(
+					{},
+					{
+						provider: "mysql",
+						schema: {},
+					},
+				),
+				plugins: [twoFactor(), username()],
+				advanced: {
+					database: {
+						generateId: "uuid",
+					},
+				},
+				user: {
+					modelName: "custom_user",
+				},
+				account: {
+					modelName: "custom_account",
+				},
+				session: {
+					modelName: "custom_session",
+				},
+				verification: {
+					modelName: "custom_verification",
+				},
+			},
+		});
+		expect(schema.code).toMatchFileSnapshot(
+			"./__snapshots__/auth-schema-mysql-uuid.txt",
+		);
+	});
+
+	it("should generate drizzle schema for PostgreSQL with uuid id", async () => {
+		const schema = await generateDrizzleSchema({
+			file: "test.drizzle",
+			adapter: drizzleAdapter(
+				{},
+				{
+					provider: "pg",
+					schema: {},
+				},
+			)({} as BetterAuthOptions),
+			options: {
+				database: drizzleAdapter(
+					{},
+					{
+						provider: "pg",
+						schema: {},
+					},
+				),
+				plugins: [twoFactor(), username()],
+				advanced: {
+					database: {
+						generateId: "uuid",
+					},
+				},
+				user: {
+					modelName: "custom_user",
+				},
+				account: {
+					modelName: "custom_account",
+				},
+				session: {
+					modelName: "custom_session",
+				},
+				verification: {
+					modelName: "custom_verification",
+				},
+			},
+		});
+		expect(schema.code).toMatchFileSnapshot(
+			"./__snapshots__/auth-schema-pg-uuid.txt",
+		);
+	});
+	it("should generate drizzle schema for SQLite with uuid id", async () => {
+		const schema = await generateDrizzleSchema({
+			file: "test.drizzle",
+			adapter: drizzleAdapter(
+				{},
+				{
+					provider: "sqlite",
+					schema: {},
+				},
+			)({} as BetterAuthOptions),
+			options: {
+				database: drizzleAdapter(
+					{},
+					{
+						provider: "sqlite",
+						schema: {},
+					},
+				),
+				plugins: [twoFactor(), username()],
+				advanced: {
+					database: {
+						generateId: "uuid",
+					},
+				},
+				user: {
+					modelName: "custom_user",
+				},
+				account: {
+					modelName: "custom_account",
+				},
+				session: {
+					modelName: "custom_session",
+				},
+				verification: {
+					modelName: "custom_verification",
+				},
+			},
+		});
+		expect(schema.code).toMatchFileSnapshot(
+			"./__snapshots__/auth-schema-sqlite-uuid.txt",
+		);
+	});
 
 	it("should generate drizzle schema for SQLite with number id", async () => {
 		const schema = await generateDrizzleSchema({
@@ -146,7 +273,7 @@ describe("generate drizzle schema for all databases", async () => {
 				plugins: [twoFactor(), username()],
 				advanced: {
 					database: {
-						useNumberId: true,
+						generateId: "serial",
 					},
 				},
 				user: {
@@ -305,7 +432,7 @@ describe("generate drizzle schema for all databases with passkey plugin", async
 				plugins: [passkey()],
 				advanced: {
 					database: {
-						useNumberId: true,
+						generateId: "serial",
 					},
 				},
 				user: {
@@ -348,7 +475,7 @@ describe("generate drizzle schema for all databases with passkey plugin", async
 				plugins: [passkey()],
 				advanced: {
 					database: {
-						useNumberId: true,
+						generateId: "serial",
 					},
 				},
 				user: {

packages/cli/test/generate.test.ts

@@ -52,7 +52,7 @@ describe("generate", async () => {
 				plugins: [twoFactor(), username()],
 				advanced: {
 					database: {
-						useNumberId: true,
+						generateId: "serial",
 					},
 				},
 			},
@@ -62,6 +62,35 @@ describe("generate", async () => {
 		);
 	});
 
+	it("should generate prisma schema with uuid id", async () => {
+		const schema = await generatePrismaSchema({
+			file: "test.prisma",
+			adapter: prismaAdapter(
+				{},
+				{
+					provider: "postgresql",
+				},
+			)({} as BetterAuthOptions),
+			options: {
+				database: prismaAdapter(
+					{},
+					{
+						provider: "postgresql",
+					},
+				),
+				plugins: [twoFactor(), username()],
+				advanced: {
+					database: {
+						generateId: "uuid",
+					},
+				},
+			},
+		});
+		expect(schema.code).toMatchFileSnapshot(
+			"./__snapshots__/schema-uuid.prisma",
+		);
+	});
+
 	it("should generate prisma schema for mongodb", async () => {
 		const schema = await generatePrismaSchema({
 			file: "test.prisma",
@@ -204,7 +233,7 @@ describe("generate", async () => {
 				plugins: [twoFactor(), username()],
 				advanced: {
 					database: {
-						useNumberId: true,
+						generateId: "serial",
 					},
 				},
 				user: {

packages/core/src/db/adapter/index.ts

@@ -82,6 +82,12 @@ export interface DBAdapterFactoryConfig<
 	 * @default true
 	 */
 	supportsNumericIds?: boolean | undefined;
+	/**
+	 * If the database supports natively generating UUIDs, set this to `true`.
+	 *
+	 * @default false
+	 */
+	supportsUUIDs?: boolean | undefined;
 	/**
 	 * If the database doesn't support JSON columns, set this to `false`.
 	 *
@@ -246,7 +252,7 @@ export interface DBAdapterFactoryConfig<
 	 *
 	 *
 	 * Notes:
-	 * - If the user enabled `useNumberId`, then this option will be ignored. Unless this adapter config has `supportsNumericIds` set to `false`.
+	 * - If the user enabled `useNumberId` or `generateId` set to `serial`, then this option will be ignored. Unless this adapter config has `supportsNumericIds` set to `false`.
 	 * - If `generateId` is `false` in the user's Better-Auth config, then this option will be ignored.
 	 * - If `generateId` is a function, then it will override this option.
 	 *

packages/telemetry/src/detectors/detect-auth-config.ts

@@ -117,7 +117,9 @@ export function getTelemetryAuthConfig(
 					options.advanced?.crossSubDomainCookies?.additionalCookies,
 			},
 			database: {
-				useNumberId: !!options.advanced?.database?.useNumberId,
+				useNumberId:
+					!!options.advanced?.database?.useNumberId ||
+					options.advanced?.database?.generateId === "serial",
 				generateId: options.advanced?.database?.generateId,
 				defaultFindManyLimit: options.advanced?.database?.defaultFindManyLimit,
 			},