Invite email addresses to rooms

crates/email/src/mailer.rs

@@ -1,3 +1,4 @@
+// Copyright 2025, 2026 Element Creations Ltd.
 // Copyright 2024, 2025 New Vector Ltd.
 // Copyright 2022-2024 The Matrix.org Foundation C.I.C.
 //
@@ -10,7 +11,9 @@ use lettre::{
     AsyncTransport, Message,
     message::{Mailbox, MessageBuilder, MultiPart},
 };
-use mas_templates::{EmailRecoveryContext, EmailVerificationContext, Templates, WithLanguage};
+use mas_templates::{
+    EmailInviteContext, EmailRecoveryContext, EmailVerificationContext, Templates, WithLanguage,
+};
 use thiserror::Error;
 
 use crate::MailTransport;
@@ -102,6 +105,28 @@ impl Mailer {
         Ok(message)
     }
 
+    fn prepare_invite_email(
+        &self,
+        to: Mailbox,
+        context: &WithLanguage<EmailInviteContext>,
+    ) -> Result<Message, Error> {
+        let plain = self.templates.render_email_invite_txt(context)?;
+
+        let html = self.templates.render_email_invite_html(context)?;
+
+        let multipart = MultiPart::alternative_plain_html(plain, html);
+
+        let subject = self.templates.render_email_invite_subject(context)?;
+
+        let message = self
+            .base_message()
+            .subject(subject.trim())
+            .to(to)
+            .multipart(multipart)?;
+
+        Ok(message)
+    }
+
     /// Send the verification email to a user
     ///
     /// # Errors
@@ -150,6 +175,29 @@ impl Mailer {
         Ok(())
     }
 
+    /// Send an invite email
+    ///
+    /// # Errors
+    ///
+    /// Will return `Err` if the email failed rendering or failed sending
+    #[tracing::instrument(
+        name = "email.invite.send",
+        skip_all,
+        fields(
+            email.to = %to,
+            email.language = %context.language(),
+        ),
+    )]
+    pub async fn send_invite_email(
+        &self,
+        to: Mailbox,
+        context: &WithLanguage<EmailInviteContext>,
+    ) -> Result<(), Error> {
+        let message = self.prepare_invite_email(to, context)?;
+        self.transport.send(message).await?;
+        Ok(())
+    }
+
     /// Test the connetion to the mail server
     ///
     /// # Errors

crates/handlers/src/admin/mod.rs

@@ -24,7 +24,7 @@ use mas_axum_utils::InternalError;
 use mas_data_model::{AppVersion, BoxRng, SiteConfig};
 use mas_http::CorsLayerExt;
 use mas_matrix::HomeserverConnection;
-use mas_policy::PolicyFactory;
+use mas_policy::{Policy, PolicyFactory};
 use mas_router::{
     ApiDoc, ApiDocCallback, OAuth2AuthorizationEndpoint, OAuth2TokenEndpoint, Route, SimpleRoute,
     UrlBuilder,
@@ -167,6 +167,7 @@ where
     PasswordManager: FromRef<S>,
     BoxRng: FromRequestParts<S>,
     CallContext: FromRequestParts<S>,
+    Policy: FromRequestParts<S>,
     Templates: FromRef<S>,
     UrlBuilder: FromRef<S>,
     Arc<PolicyFactory>: FromRef<S>,

crates/handlers/src/admin/model.rs

@@ -647,6 +647,10 @@ pub struct UserRegistrationToken {
     /// identity is then established by verifying their email address.
     passwordless: bool,
 
+    /// A room opened once the user has registered or signed in through the
+    /// token's link. If null, the link opens no room.
+    room_id: Option<String>,
+
     /// Maximum number of times this token can be used
     usage_limit: Option<u32>,
 
@@ -684,6 +688,7 @@ impl UserRegistrationToken {
             username: token.username,
             email: token.email,
             passwordless: token.passwordless,
+            room_id: token.room_id,
             usage_limit: token.usage_limit,
             times_used: token.times_used,
             created_at: token.created_at,
@@ -715,6 +720,7 @@ impl UserRegistrationToken {
                 username: None,
                 email: None,
                 passwordless: false,
+                room_id: None,
                 usage_limit: Some(10),
                 times_used: 5,
                 created_at: DateTime::default(),
@@ -730,6 +736,7 @@ impl UserRegistrationToken {
                 username: None,
                 email: None,
                 passwordless: false,
+                room_id: None,
                 usage_limit: None,
                 times_used: 0,
                 created_at: DateTime::default(),

crates/handlers/src/admin/v1/mod.rs

@@ -14,7 +14,7 @@ use aide::axum::{
 use axum::extract::{FromRef, FromRequestParts};
 use mas_data_model::{AppVersion, BoxRng, SiteConfig};
 use mas_matrix::HomeserverConnection;
-use mas_policy::PolicyFactory;
+use mas_policy::{Policy, PolicyFactory};
 use mas_router::UrlBuilder;
 
 use super::call_context::CallContext;
@@ -45,6 +45,7 @@ where
     UrlBuilder: FromRef<S>,
     BoxRng: FromRequestParts<S>,
     CallContext: FromRequestParts<S>,
+    Policy: FromRequestParts<S>,
 {
     ApiRouter::<S>::new()
         .api_route(
@@ -210,6 +211,13 @@ where
                 self::user_registration_tokens::add_doc,
             ),
         )
+        .api_route(
+            "/user-registration-tokens/invite-emails",
+            post_with(
+                self::user_registration_tokens::invite_emails,
+                self::user_registration_tokens::invite_emails_doc,
+            ),
+        )
         .api_route(
             "/user-registration-tokens/{id}",
             get_with(