From 2d8c66186c0c37228f11fbdf878961d2d9c1bdef Mon Sep 17 00:00:00 2001
From: tdgao <mr.trumgao@gmail.com>
Date: Fri, 17 Apr 2026 16:54:44 -0600
Subject: [PATCH] feat: implement under 13 DOB guard and email/password
 validation route

---
 .../src/components/ui/auth/CreateAccount.vue  | 87 +++++++++++++++----
 .../src/components/ui/auth/SignUp.vue         | 53 +----------
 apps/frontend/src/pages/auth/sign-up.vue      | 57 ++++++++++--
 .../src/modules/labrinth/auth/v2.ts           | 16 ++++
 .../api-client/src/modules/labrinth/types.ts  |  6 ++
 5 files changed, 146 insertions(+), 73 deletions(-)

diff --git a/apps/frontend/src/components/ui/auth/CreateAccount.vue b/apps/frontend/src/components/ui/auth/CreateAccount.vue
index 288d1ab5c0..67e318f49e 100644
--- a/apps/frontend/src/components/ui/auth/CreateAccount.vue
+++ b/apps/frontend/src/components/ui/auth/CreateAccount.vue
@@ -15,25 +15,29 @@
 			<input
 				id="create-account-dob"
 				v-model="dateOfBirthModel"
-				class="scheme-dark w-full border-0 bg-surface-4 text-lg text-contrast outline-none [color-scheme:dark]"
+				class="scheme-dark w-full border-0 bg-surface-4 text-lg text-primary outline-none [color-scheme:dark]"
 				type="date"
 				:max="maxBirthDate"
 			/>
-			<div>You must be over 13 years old to use Modrinth.</div>
-			<Admonition type="info">
-				<div class="flex flex-col gap-1.5 leading-normal">
-					<div>
-						{{ formatMessage(messages.infoPanelText) }}
+			<div>
+				{{ formatMessage(messages.over13HelperText) }}
+			</div>
+			<Admonition :type="'info'">
+				<template #header>
+					<div class="-mb-2 flex flex-col gap-1.5 font-normal leading-normal">
+						<div>
+							{{ formatMessage(messages.infoPanelText) }}
+						</div>
+						<a
+							class="w-fit text-link underline"
+							:href="sourceCodeUrl"
+							target="_blank"
+							rel="noopener noreferrer"
+						>
+							{{ formatMessage(messages.relevantSourceCodeText) }}
+						</a>
 					</div>
-					<a
-						class="w-fit text-link"
-						:href="sourceCodeUrl"
-						target="_blank"
-						rel="noopener noreferrer"
-					>
-						{{ formatMessage(messages.relevantSourceCodeText) }}
-					</a>
-				</div>
+				</template>
 			</Admonition>
 		</section>
 
@@ -71,7 +75,7 @@
 			<button
 				class="!w-full font-bold"
 				:disabled="globals?.captcha_enabled ? !tokenModel : false"
-				@click="onCompleteSignUp()"
+				@click="onCompleteSignUpClick"
 			>
 				{{ formatMessage(messages.completeSignUpButton) }}
 			</button>
@@ -85,6 +89,7 @@ import {
 	ButtonStyled,
 	Checkbox,
 	defineMessages,
+	injectNotificationManager,
 	StyledInput,
 	useVIntl,
 } from '@modrinth/ui'
@@ -120,7 +125,7 @@ const props = defineProps({
 	sourceCodeUrl: {
 		type: String,
 		default:
-			'https://github.com/modrinth/labrinth/blob/main/apps/labrinth/src/routes/internal/flows.rs',
+			'https://github.com/modrinth/code/blob/main/apps/frontend/src/components/ui/auth/CreateAccount.vue',
 	},
 	onCompleteSignUp: {
 		type: Function,
@@ -165,8 +170,40 @@ const maxBirthDate = computed(() => {
 	return date.toISOString().slice(0, 10)
 })
 
+const isDateOfBirthMissing = computed(() => props.requiresDob && dateOfBirthModel.value === '')
+
+const isUnder13 = computed(
+	() =>
+		props.requiresDob &&
+		dateOfBirthModel.value !== '' &&
+		dateOfBirthModel.value > maxBirthDate.value,
+)
+
+const { addNotification } = injectNotificationManager()
 const { formatMessage } = useVIntl()
 
+function onCompleteSignUpClick() {
+	if (isDateOfBirthMissing.value) {
+		addNotification({
+			title: formatMessage(messages.dateOfBirthRequiredTitle),
+			text: formatMessage(messages.dateOfBirthRequiredText),
+			type: 'warning',
+		})
+		return
+	}
+
+	if (isUnder13.value) {
+		addNotification({
+			title: formatMessage(messages.ageRequirementWarningTitle),
+			text: formatMessage(messages.under13HelperText),
+			type: 'error',
+		})
+		return
+	}
+
+	props.onCompleteSignUp()
+}
+
 const messages = defineMessages({
 	title: {
 		id: 'auth.create-account.title',
@@ -176,10 +213,26 @@ const messages = defineMessages({
 		id: 'auth.create-account.date-of-birth.label',
 		defaultMessage: 'Date of birth',
 	},
+	dateOfBirthRequiredTitle: {
+		id: 'auth.create-account.date-of-birth.required.title',
+		defaultMessage: 'Date of birth required',
+	},
+	dateOfBirthRequiredText: {
+		id: 'auth.create-account.date-of-birth.required.text',
+		defaultMessage: 'Please enter your date of birth before continuing.',
+	},
 	over13HelperText: {
 		id: 'auth.create-account.date-of-birth.over13-helper',
 		defaultMessage: 'You must be over 13 years old to use Modrinth.',
 	},
+	under13HelperText: {
+		id: 'auth.create-account.date-of-birth.under13-helper',
+		defaultMessage: 'You cannot create an account at Modrinth unless you are 13 years old.',
+	},
+	ageRequirementWarningTitle: {
+		id: 'auth.create-account.age-requirement.warning-title',
+		defaultMessage: 'Age requirement',
+	},
 	infoPanelText: {
 		id: 'auth.create-account.info-panel.text',
 		defaultMessage:
diff --git a/apps/frontend/src/components/ui/auth/SignUp.vue b/apps/frontend/src/components/ui/auth/SignUp.vue
index 9b46aca712..e12ebd14b1 100644
--- a/apps/frontend/src/components/ui/auth/SignUp.vue
+++ b/apps/frontend/src/components/ui/auth/SignUp.vue
@@ -79,13 +79,6 @@
 				wrapper-class="w-full"
 			/>
 
-			<Checkbox
-				v-model="subscribeModel"
-				class="subscribe-btn"
-				:label="formatMessage(messages.subscribeLabel)"
-				:description="formatMessage(messages.subscribeLabel)"
-			/>
-
 			<p v-if="!routeQuery.launcher">
 				<IntlFormatted :message-id="messages.legalDisclaimer">
 					<template #terms-link="{ children }">
@@ -101,17 +94,11 @@
 				</IntlFormatted>
 			</p>
 
-			<HCaptcha
-				v-if="globals?.captcha_enabled && emailModel && passwordModel"
-				:ref="onSetCaptchaRef"
-				v-model="tokenModel"
-			/>
-
 			<ButtonStyled color="brand">
 				<button
 					class="!w-full"
-					:disabled="globals?.captcha_enabled ? !tokenModel : false"
-					@click="onCreateAccount()"
+					:disabled="!emailModel || !passwordModel"
+					@click="onContinueWithEmail()"
 				>
 					{{ formatMessage(messages.continueWithEmail) }} <RightArrowIcon />
 				</button>
@@ -147,7 +134,6 @@ import {
 } from '@modrinth/assets'
 import {
 	ButtonStyled,
-	Checkbox,
 	commonMessages,
 	defineMessages,
 	IntlFormatted,
@@ -156,7 +142,6 @@ import {
 } from '@modrinth/ui'
 import { computed } from 'vue'
 
-import HCaptcha from '@/components/ui/auth/HCaptcha.vue'
 import { getAuthUrl } from '@/composables/auth.ts'
 
 const props = defineProps({
@@ -172,10 +157,6 @@ const props = defineProps({
 		type: Object,
 		default: () => ({}),
 	},
-	globals: {
-		type: Object,
-		default: null,
-	},
 	email: {
 		type: String,
 		default: '',
@@ -184,29 +165,17 @@ const props = defineProps({
 		type: String,
 		default: '',
 	},
-	token: {
-		type: String,
-		default: '',
-	},
-	subscribe: {
-		type: Boolean,
-		default: false,
-	},
 	onToggleOtherOptions: {
 		type: Function,
 		default: () => {},
 	},
-	onCreateAccount: {
+	onContinueWithEmail: {
 		type: Function,
 		default: () => {},
 	},
-	onSetCaptchaRef: {
-		type: Function,
-		default: undefined,
-	},
 })
 
-const emit = defineEmits(['update:email', 'update:password', 'update:token', 'update:subscribe'])
+const emit = defineEmits(['update:email', 'update:password'])
 
 const emailModel = computed({
 	get: () => props.email,
@@ -218,16 +187,6 @@ const passwordModel = computed({
 	set: (value) => emit('update:password', value),
 })
 
-const tokenModel = computed({
-	get: () => props.token,
-	set: (value) => emit('update:token', value),
-})
-
-const subscribeModel = computed({
-	get: () => props.subscribe,
-	set: (value) => emit('update:subscribe', value),
-})
-
 const { formatMessage } = useVIntl()
 
 const messages = defineMessages({
@@ -239,10 +198,6 @@ const messages = defineMessages({
 		id: 'auth.continue-with-provider',
 		defaultMessage: 'Continue with {provider}',
 	},
-	subscribeLabel: {
-		id: 'auth.sign-up.subscribe.label',
-		defaultMessage: 'Subscribe to updates about Modrinth',
-	},
 	legalDisclaimer: {
 		id: 'auth.sign-up.legal-dislaimer',
 		defaultMessage:
diff --git a/apps/frontend/src/pages/auth/sign-up.vue b/apps/frontend/src/pages/auth/sign-up.vue
index 5e18477b15..398232da5c 100644
--- a/apps/frontend/src/pages/auth/sign-up.vue
+++ b/apps/frontend/src/pages/auth/sign-up.vue
@@ -1,15 +1,22 @@
 <template>
 	<SignUpView
+		v-if="!isCreateAccountStep"
 		v-model:email="email"
 		v-model:password="password"
-		v-model:token="token"
-		v-model:subscribe="subscribe"
 		:redirect-target="redirectTarget"
 		:show-other-options="showOtherOptions"
 		:route-query="route.query"
-		:globals="globals"
 		:on-toggle-other-options="toggleOtherOptions"
-		:on-create-account="createAccount"
+		:on-continue-with-email="continueWithEmail"
+	/>
+	<CreateAccountView
+		v-else
+		v-model:date-of-birth="dateOfBirth"
+		v-model:username="username"
+		v-model:token="token"
+		v-model:subscribe="subscribe"
+		:globals="globals"
+		:on-complete-sign-up="createAccount"
 		:on-set-captcha-ref="setCaptchaRef"
 	/>
 </template>
@@ -24,6 +31,7 @@ import {
 } from '@modrinth/ui'
 import { useQuery } from '@tanstack/vue-query'
 
+import CreateAccountView from '@/components/ui/auth/CreateAccount.vue'
 import SignUpView from '@/components/ui/auth/SignUp.vue'
 
 const client = injectModrinthClient()
@@ -35,6 +43,14 @@ const messages = defineMessages({
 		id: 'auth.sign-up.title',
 		defaultMessage: 'Sign Up',
 	},
+	ageRequirementWarningTitle: {
+		id: 'auth.sign-up.age-requirement.warning-title',
+		defaultMessage: 'Age requirement',
+	},
+	under13HelperText: {
+		id: 'auth.create-account.date-of-birth.under13-helper',
+		defaultMessage: 'You cannot create an account at Modrinth unless you are 13 years old.',
+	},
 })
 
 useHead({
@@ -46,6 +62,7 @@ const route = useNativeRoute()
 
 const redirectTarget = route.query.redirect
 const showOtherOptions = ref(false)
+const isCreateAccountStep = ref(false)
 
 if (auth.value.user) {
 	await navigateTo('/dashboard')
@@ -73,12 +90,38 @@ const { data: globals } = useQuery({
 
 const email = ref('')
 const password = ref('')
+const dateOfBirth = ref('')
+const username = ref('')
 const token = ref('')
 const subscribe = ref(false)
 
+async function continueWithEmail() {
+	startLoading()
+	try {
+		const generatedUsername = generateUsernameFromEmail(email.value)
+
+		await client.labrinth.auth_v2.validateCreateAccount({
+			username: generatedUsername,
+			password: password.value,
+			email: email.value,
+		})
+
+		token.value = ''
+		username.value = generatedUsername
+		isCreateAccountStep.value = true
+	} catch (err) {
+		addNotification({
+			title: formatMessage(commonMessages.errorNotificationTitle),
+			text: err.data ? err.data.description : err,
+			type: 'error',
+		})
+	}
+	stopLoading()
+}
+
 function generateUsernameFromEmail(emailAddress) {
-	const [localPart = '', domainPart = ''] = emailAddress.trim().toLowerCase().split('@')
-	const sanitized = `${localPart}_${domainPart}`
+	const [localPart = ''] = emailAddress.trim().toLowerCase().split('@')
+	const sanitized = localPart
 		.replace(/[^a-zA-Z0-9_-]/g, '_')
 		.replace(/_+/g, '_')
 		.replace(/^_+|_+$/g, '')
@@ -90,7 +133,7 @@ async function createAccount() {
 	startLoading()
 	try {
 		const res = await client.labrinth.auth_v2.createAccount({
-			username: generateUsernameFromEmail(email.value),
+			username: username.value.trim() || generateUsernameFromEmail(email.value),
 			password: password.value,
 			email: email.value,
 			challenge: token.value,
diff --git a/packages/api-client/src/modules/labrinth/auth/v2.ts b/packages/api-client/src/modules/labrinth/auth/v2.ts
index 53c9b2669e..e1829d7726 100644
--- a/packages/api-client/src/modules/labrinth/auth/v2.ts
+++ b/packages/api-client/src/modules/labrinth/auth/v2.ts
@@ -57,6 +57,22 @@ export class LabrinthAuthV2Module extends AbstractModule {
 		})
 	}
 
+	/**
+	 * Validate email/password inputs for account creation without creating an account.
+	 *
+	 * @param data - Prospective account credentials
+	 */
+	public async validateCreateAccount(
+		data: Labrinth.Auth.v2.ValidateCreateAccountRequest,
+	): Promise<void> {
+		return this.client.request(`/auth/create/validate`, {
+			api: 'labrinth',
+			version: 2,
+			method: 'POST',
+			body: data,
+		})
+	}
+
 	/**
 	 * Create a new account from an OAuth callback flow state
 	 *
diff --git a/packages/api-client/src/modules/labrinth/types.ts b/packages/api-client/src/modules/labrinth/types.ts
index 1e03777162..78b84b0cac 100644
--- a/packages/api-client/src/modules/labrinth/types.ts
+++ b/packages/api-client/src/modules/labrinth/types.ts
@@ -278,6 +278,12 @@ export namespace Labrinth {
 				session: string
 			}
 
+			export type ValidateCreateAccountRequest = {
+				username: string
+				password: string
+				email: string
+			}
+
 			export type CreateOAuthAccountRequest = {
 				username: string
 				state: string