feat: enable email otp login

src/plugins.ts

@@ -1,5 +1,6 @@
 import type { BetterAuthPlugin } from "better-auth";
-import { captcha, haveIBeenPwned, openAPI } from "better-auth/plugins";
+import { captcha, emailOTP, haveIBeenPwned, openAPI } from "better-auth/plugins";
+import { buildAuthEmail, sendEmail } from "./email";
 import type { Env } from "./env";
 
 export function createAuthPlugins(env: Env): BetterAuthPlugin[] {
@@ -8,6 +9,17 @@ export function createAuthPlugins(env: Env): BetterAuthPlugin[] {
     haveIBeenPwned({
       customPasswordCompromisedMessage: "This password has appeared in a data breach.",
     }),
+    emailOTP({
+      otpLength: 6,
+      expiresIn: 300,
+      allowedAttempts: 3,
+      storeOTP: "hashed",
+      sendVerificationOnSignUp: true,
+      overrideDefaultEmailVerification: false,
+      sendVerificationOTP: async ({ email, otp }) => {
+        await sendEmail(env, buildAuthEmail({ kind: "email-otp", to: email, otp }));
+      },
+    }),
   ];
 
   if (env.CAPTCHA_PROVIDER === "cloudflare-turnstile" && env.CAPTCHA_SECRET_KEY) {

tests/auth-config.test.ts

@@ -90,4 +90,12 @@ describe("auth plugins", () => {
     });
     expect(plugins.map((plugin) => plugin.id)).toContain("captcha");
   });
+
+  it("enables email otp plugin by default", () => {
+    const plugins = createAuthPlugins({
+      BETTER_AUTH_URL: "http://localhost:8788",
+      TRUSTED_ORIGINS: "http://localhost:8787",
+    });
+    expect(plugins.map((plugin) => plugin.id)).toContain("email-otp");
+  });
 });