refactor: Update logic for checking if a username is available

changelog.d/+85568e80.feature.md

@@ -1 +0,0 @@
-Added support for Matrix 1.16's `state_after` feature, allowing clients which understand it to sync room state changes more reliably. Contributed by @ginger.

changelog.d/917.bugfix.md

@@ -1 +0,0 @@
-Adjusted legacy sync logic to no longer use the `roomsynctoken_shortstatehash` database column. Once this change has been confirmed to be stable and reliable, a future update will remove it entirely, significantly decreasing database sizes. Contributed by @ginger.

conduwuit-example.toml

@@ -1793,9 +1793,11 @@
 #stream_amplification = 1024
 
 # Number of sender task workers; determines sender parallelism. Default is
-# core count. Override by setting a different value.
+# '0' which means the value is determined internally, likely matching the
+# number of tokio worker-threads or number of cores, etc. Override by
+# setting a non-zero value.
 #
-#sender_workers = core count
+#sender_workers = 0
 
 # Enables listener sockets; can be set to false to disable listening. This
 # option is intended for developer/diagnostic purposes only.

src/api/admin/rooms/ban.rs

@@ -13,7 +13,7 @@ pub(crate) async fn ban_room(
 	State(services): State<crate::State>,
 	body: Ruma<rooms::ban::v1::Request>,
 ) -> Result<rooms::ban::v1::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if !services.users.is_admin(sender_user).await {
 		return Err!(Request(Forbidden("Only server administrators can use this endpoint")));
 	}

src/api/admin/rooms/list.rs

@@ -13,7 +13,7 @@ pub(crate) async fn list_rooms(
 	State(services): State<crate::State>,
 	body: Ruma<rooms::list::v1::Request>,
 ) -> Result<rooms::list::v1::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if !services.users.is_admin(sender_user).await {
 		return Err!(Request(Forbidden("Only server administrators can use this endpoint")));
 	}

src/api/client/account/mod.rs

@@ -27,7 +27,7 @@ use ruma::{
 use service::{mailer::messages, uiaa::UiaaInitiator, users::HashedPassword};
 
 use super::{DEVICE_ID_LENGTH, TOKEN_LENGTH};
-use crate::Ruma;
+use crate::{Ruma, router::ClientIdentity};
 
 pub(crate) mod register;
 pub(crate) mod threepid;
@@ -49,41 +49,16 @@ pub(crate) async fn get_register_available_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_username_availability::v3::Request>,
 ) -> Result<get_username_availability::v3::Response> {
-	// Validate user id
-	let user_id =
-		match UserId::parse_with_server_name(&body.username, services.globals.server_name()) {
-			| Ok(user_id) => {
-				if let Err(e) = user_id.validate_strict() {
-					return Err!(Request(InvalidUsername(debug_warn!(
-						"Username {} contains disallowed characters or spaces: {e}",
-						body.username
-					))));
-				}
-
-				user_id
-			},
-			| Err(e) => {
-				return Err!(Request(InvalidUsername(debug_warn!(
-					"Username {} is not valid: {e}",
-					body.username
-				))));
-			},
-		};
-
-	// Check if username is creative enough
-	if services.users.exists(&user_id).await {
-		return Err!(Request(UserInUse("User ID is not available.")));
-	}
-
-	if let Some(ref info) = body.appservice_info {
-		if !info.is_user_match(&user_id) {
-			return Err!(Request(Exclusive("Username is not in an appservice namespace.")));
-		}
-	}
-
-	if services.appservice.is_exclusive_user_id(&user_id).await {
-		return Err!(Request(Exclusive("Username is reserved by an appservice.")));
-	}
+	let _ = services
+		.users
+		.determine_registration_user_id(
+			Some(body.username.clone()),
+			None,
+			body.identity
+				.as_ref()
+				.and_then(ClientIdentity::appservice_info),
+		)
+		.await?;
 
 	Ok(get_username_availability::v3::Response::new(true))
 }
@@ -111,7 +86,7 @@ pub(crate) async fn change_password_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<change_password::v3::Request>,
 ) -> Result<change_password::v3::Response> {
-	let identity = if let Some(ref user_id) = body.sender_user {
+	let identity = if let Some(identity) = body.identity.as_ref() {
 		// A signed-in user is trying to change their password, prompt them for their
 		// existing one
 
@@ -121,7 +96,7 @@ pub(crate) async fn change_password_route(
 				&body.auth,
 				vec![AuthFlow::new(vec![AuthType::Password])],
 				Box::default(),
-				Some(UiaaInitiator::new(user_id, body.sender_device())),
+				Some(UiaaInitiator::new(identity.sender_user(), identity.sender_device())),
 			)
 			.await?
 	} else {
@@ -157,7 +132,12 @@ pub(crate) async fn change_password_route(
 		services
 			.users
 			.all_device_ids(&sender_user)
-			.ready_filter(|id| *id != body.sender_device())
+			.ready_filter(|id| {
+				body.identity
+					.as_ref()
+					.and_then(|identity| identity.sender_device())
+					.is_none_or(|sender_device| sender_device != *id)
+			})
 			.for_each(async |id| services.users.remove_device(&sender_user, &id).await)
 			.await;
 
@@ -173,7 +153,12 @@ pub(crate) async fn change_password_route(
 					.await
 					.ok()
 					.as_ref()
-					.is_some_and(|pusher_device| pusher_device != body.sender_device())
+					.is_some_and(|pusher_device| {
+						body.identity
+							.as_ref()
+							.and_then(|identity| identity.sender_device())
+							.is_none_or(|sender_device| sender_device != *pusher_device)
+					})
 					.then_some(pushkey)
 			})
 			.for_each(async |pushkey| {
@@ -241,9 +226,11 @@ pub(crate) async fn whoami_route(
 	State(_): State<crate::State>,
 	body: Ruma<whoami::v3::Request>,
 ) -> Result<whoami::v3::Response> {
-	Ok(assign!(whoami::v3::Response::new(body.sender_user().to_owned(), false), {
-		device_id: body.sender_device,
-	}))
+	Ok(
+		assign!(whoami::v3::Response::new(body.identity.sender_user().to_owned(), false), {
+			device_id: body.identity.sender_device().map(ToOwned::to_owned),
+		}),
+	)
 }
 
 /// # `POST /_matrix/client/r0/account/deactivate`
@@ -265,11 +252,13 @@ pub(crate) async fn deactivate_route(
 ) -> Result<deactivate::v3::Response> {
 	// Authentication for this endpoint is technically optional,
 	// but we require the user to be logged in
-	let sender_user = body
-		.sender_user
+	let identity = body
+		.identity
 		.as_ref()
 		.ok_or_else(|| err!(Request(MissingToken("Missing access token."))))?;
 
+	let sender_user = identity.sender_user();
+
 	if !services.config.allow_deactivation {
 		return Err!(Request(Unauthorized(
 			"You may not deactivate your own account. Contact your server's administrator for \
@@ -280,7 +269,7 @@ pub(crate) async fn deactivate_route(
 	// Prompt the user to confirm with their password using UIAA
 	let _ = services
 		.uiaa
-		.authenticate_password(&body.auth, sender_user, body.sender_device(), None)
+		.authenticate_password(&body.auth, sender_user, identity.sender_device(), None)
 		.await?;
 
 	// Remove profile pictures and display name

src/api/client/account/register.rs

@@ -48,7 +48,7 @@ pub(crate) async fn register_route(
 	let allow_registration =
 		services.config.allow_registration || services.firstrun.is_first_run();
 
-	if !allow_registration && body.appservice_info.is_none() {
+	if !allow_registration && body.identity.is_none() {
 		info!(
 			?body.username,
 			?body.initial_device_display_name,
@@ -61,7 +61,7 @@ pub(crate) async fn register_route(
 	}
 
 	let user_id = if body.body.login_type == Some(LoginType::ApplicationService) {
-		let Some(appservice_info) = &body.appservice_info else {
+		let Some(appservice_info) = &body.identity else {
 			return Err!(Request(Forbidden(
 				"Only appservices can use the appservice login type."
 			)));

src/api/client/account/threepid.rs

@@ -13,7 +13,7 @@ use ruma::{
 };
 use service::mailer::messages;
 
-use crate::Ruma;
+use crate::{Ruma, router::ClientIdentity};
 
 /// # `GET _matrix/client/v3/account/3pid`
 ///
@@ -22,7 +22,7 @@ pub(crate) async fn third_party_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_3pids::v3::Request>,
 ) -> Result<get_3pids::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let mut threepids = vec![];
 
 	if let Some(email) = services
@@ -53,6 +53,14 @@ pub(crate) async fn request_3pid_management_token_via_email_route(
 	State(services): State<crate::State>,
 	body: Ruma<request_3pid_management_token_via_email::v3::Request>,
 ) -> Result<request_3pid_management_token_via_email::v3::Response> {
+	// Authentication for this endpoint is technically optional,
+	// but we require the user to be logged in
+	let sender_user = body
+		.identity
+		.as_ref()
+		.map(ClientIdentity::sender_user)
+		.ok_or_else(|| err!(Request(MissingToken("Missing access token."))))?;
+
 	if !services.threepid.email_requirement().may_change() {
 		return Err!(Request(Forbidden("You may not change your email address.")));
 	}
@@ -76,7 +84,7 @@ pub(crate) async fn request_3pid_management_token_via_email_route(
 			Mailbox::new(None, email),
 			|verification_link| messages::ChangeEmail {
 				server_name: services.config.server_name.as_str(),
-				user_id: body.sender_user.as_deref(),
+				user_id: Some(sender_user),
 				verification_link,
 			},
 			&body.client_secret,
@@ -107,8 +115,6 @@ pub(crate) async fn add_3pid_route(
 	State(services): State<crate::State>,
 	body: Ruma<add_3pid::v3::Request>,
 ) -> Result<add_3pid::v3::Response> {
-	let sender_user = body.sender_user();
-
 	if !services.threepid.email_requirement().may_change() {
 		return Err!(Request(Forbidden("You may not change your email address.")));
 	}
@@ -116,7 +122,12 @@ pub(crate) async fn add_3pid_route(
 	// Require password auth to add an email
 	let _ = services
 		.uiaa
-		.authenticate_password(&body.auth, sender_user, body.sender_device(), None)
+		.authenticate_password(
+			&body.auth,
+			body.identity.sender_user(),
+			body.identity.sender_device(),
+			None,
+		)
 		.await?;
 
 	let email = services
@@ -128,7 +139,7 @@ pub(crate) async fn add_3pid_route(
 
 	services
 		.threepid
-		.associate_localpart_email(sender_user.localpart(), &email)
+		.associate_localpart_email(body.identity.sender_user().localpart(), &email)
 		.await?;
 
 	Ok(add_3pid::v3::Response::new())
@@ -139,8 +150,6 @@ pub(crate) async fn delete_3pid_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_3pid::v3::Request>,
 ) -> Result<delete_3pid::v3::Response> {
-	let sender_user = body.sender_user();
-
 	if body.medium != Medium::Email {
 		return Ok(delete_3pid::v3::Response::new(ThirdPartyIdRemovalStatus::NoSupport));
 	}
@@ -151,7 +160,7 @@ pub(crate) async fn delete_3pid_route(
 
 	if services
 		.threepid
-		.disassociate_localpart_email(sender_user.localpart())
+		.disassociate_localpart_email(body.identity.sender_user().localpart())
 		.await
 		.is_none()
 	{

src/api/client/account_data.rs

@@ -22,9 +22,9 @@ pub(crate) async fn set_global_account_data_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_global_account_data::v3::Request>,
 ) -> Result<set_global_account_data::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
-	if sender_user != body.user_id && body.appservice_info.is_none() {
+	if sender_user != body.user_id && !body.identity.is_appservice() {
 		return Err!(Request(Forbidden("You cannot set account data for other users.")));
 	}
 
@@ -47,9 +47,9 @@ pub(crate) async fn set_room_account_data_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_room_account_data::v3::Request>,
 ) -> Result<set_room_account_data::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
-	if sender_user != body.user_id && body.appservice_info.is_none() {
+	if sender_user != body.user_id && !body.identity.is_appservice() {
 		return Err!(Request(Forbidden("You cannot set account data for other users.")));
 	}
 
@@ -72,9 +72,9 @@ pub(crate) async fn get_global_account_data_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_global_account_data::v3::Request>,
 ) -> Result<get_global_account_data::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
-	if sender_user != body.user_id && body.appservice_info.is_none() {
+	if sender_user != body.user_id && !body.identity.is_appservice() {
 		return Err!(Request(Forbidden("You cannot get account data of other users.")));
 	}
 
@@ -94,9 +94,9 @@ pub(crate) async fn get_room_account_data_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_room_account_data::v3::Request>,
 ) -> Result<get_room_account_data::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
-	if sender_user != body.user_id && body.appservice_info.is_none() {
+	if sender_user != body.user_id && !body.identity.is_appservice() {
 		return Err!(Request(Forbidden("You cannot get account data of other users.")));
 	}
 

src/api/client/admin/suspend.rs

@@ -12,10 +12,11 @@ pub(crate) async fn get_suspended_status(
 	State(services): State<crate::State>,
 	body: Ruma<get_suspended::v1::Request>,
 ) -> Result<get_suspended::v1::Response> {
-	let sender_user = body.sender_user();
-
-	let (admin, active) =
-		join(services.users.is_admin(sender_user), services.users.is_active(&body.user_id)).await;
+	let (admin, active) = join(
+		services.users.is_admin(body.identity.sender_user()),
+		services.users.is_active(&body.user_id),
+	)
+	.await;
 	if !admin {
 		return Err!(Request(Forbidden("Only server administrators can use this endpoint")));
 	}
@@ -37,7 +38,7 @@ pub(crate) async fn put_suspended_status(
 	State(services): State<crate::State>,
 	body: Ruma<set_suspended::v1::Request>,
 ) -> Result<set_suspended::v1::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let (sender_admin, active, target_admin) = join3(
 		services.users.is_admin(sender_user),

src/api/client/alias.rs

@@ -11,7 +11,7 @@ pub(crate) async fn create_alias_route(
 	State(services): State<crate::State>,
 	body: Ruma<create_alias::v3::Request>,
 ) -> Result<create_alias::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
@@ -19,7 +19,7 @@ pub(crate) async fn create_alias_route(
 	services
 		.rooms
 		.alias
-		.appservice_checks(&body.room_alias, &body.appservice_info)
+		.appservice_checks(&body.room_alias, body.identity.appservice_info())
 		.await?;
 
 	// this isn't apart of alias_checks or delete alias route because we should
@@ -59,7 +59,7 @@ pub(crate) async fn delete_alias_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_alias::v3::Request>,
 ) -> Result<delete_alias::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
@@ -67,7 +67,7 @@ pub(crate) async fn delete_alias_route(
 	services
 		.rooms
 		.alias
-		.appservice_checks(&body.room_alias, &body.appservice_info)
+		.appservice_checks(&body.room_alias, body.identity.appservice_info())
 		.await?;
 
 	services

src/api/client/appservice.rs

@@ -1,5 +1,5 @@
 use axum::extract::State;
-use conduwuit::{Err, Result, err};
+use conduwuit::{Err, Result};
 use ruma::{
 	api::{appservice::ping, client::appservice::request_ping},
 	assign,
@@ -15,9 +15,7 @@ pub(crate) async fn appservice_ping(
 	State(services): State<crate::State>,
 	body: Ruma<request_ping::v1::Request>,
 ) -> Result<request_ping::v1::Response> {
-	let appservice_info = body.appservice_info.as_ref().ok_or_else(|| {
-		err!(Request(Forbidden("This endpoint can only be called by appservices.")))
-	})?;
+	let appservice_info = &body.identity;
 
 	if body.appservice_id != appservice_info.registration.id {
 		return Err!(Request(Forbidden(

src/api/client/backup.rs

@@ -25,7 +25,7 @@ pub(crate) async fn create_backup_version_route(
 ) -> Result<create_backup_version::v3::Response> {
 	let version = services
 		.key_backups
-		.create_backup(body.sender_user(), &body.algorithm)?;
+		.create_backup(body.identity.sender_user(), &body.algorithm)?;
 
 	Ok(create_backup_version::v3::Response::new(version))
 }
@@ -40,7 +40,7 @@ pub(crate) async fn update_backup_version_route(
 ) -> Result<update_backup_version::v3::Response> {
 	services
 		.key_backups
-		.update_backup(body.sender_user(), &body.version, &body.algorithm)
+		.update_backup(body.identity.sender_user(), &body.version, &body.algorithm)
 		.await?;
 
 	Ok(update_backup_version::v3::Response::new())
@@ -55,11 +55,11 @@ pub(crate) async fn get_latest_backup_info_route(
 ) -> Result<get_latest_backup_info::v3::Response> {
 	let (version, algorithm) = services
 		.key_backups
-		.get_latest_backup(body.sender_user())
+		.get_latest_backup(body.identity.sender_user())
 		.await
 		.map_err(|_| err!(Request(NotFound("Key backup does not exist."))))?;
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &version).await;
+	let (count, etag) = get_count_etag(&services, body.identity.sender_user(), &version).await;
 
 	Ok(get_latest_backup_info::v3::Response::new(algorithm, count, etag, version))
 }
@@ -73,13 +73,14 @@ pub(crate) async fn get_backup_info_route(
 ) -> Result<get_backup_info::v3::Response> {
 	let algorithm = services
 		.key_backups
-		.get_backup(body.sender_user(), &body.version)
+		.get_backup(body.identity.sender_user(), &body.version)
 		.await
 		.map_err(|_| {
 			err!(Request(NotFound("Key backup does not exist at version {:?}", body.version)))
 		})?;
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(get_backup_info::v3::Response::new(algorithm, count, etag, body.version.clone()))
 }
@@ -96,7 +97,7 @@ pub(crate) async fn delete_backup_version_route(
 ) -> Result<delete_backup_version::v3::Response> {
 	services
 		.key_backups
-		.delete_backup(body.sender_user(), &body.version)
+		.delete_backup(body.identity.sender_user(), &body.version)
 		.await;
 
 	Ok(delete_backup_version::v3::Response::new())
@@ -116,7 +117,7 @@ pub(crate) async fn add_backup_keys_route(
 ) -> Result<add_backup_keys::v3::Response> {
 	if services
 		.key_backups
-		.get_latest_backup_version(body.sender_user())
+		.get_latest_backup_version(body.identity.sender_user())
 		.await
 		.is_ok_and(|version| version != body.version)
 	{
@@ -129,12 +130,19 @@ pub(crate) async fn add_backup_keys_route(
 		for (session_id, key_data) in &room.sessions {
 			services
 				.key_backups
-				.add_key(body.sender_user(), &body.version, room_id, session_id, key_data)
+				.add_key(
+					body.identity.sender_user(),
+					&body.version,
+					room_id,
+					session_id,
+					key_data,
+				)
 				.await?;
 		}
 	}
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(add_backup_keys::v3::Response::new(etag, count))
 }
@@ -153,7 +161,7 @@ pub(crate) async fn add_backup_keys_for_room_route(
 ) -> Result<add_backup_keys_for_room::v3::Response> {
 	if services
 		.key_backups
-		.get_latest_backup_version(body.sender_user())
+		.get_latest_backup_version(body.identity.sender_user())
 		.await
 		.is_ok_and(|version| version != body.version)
 	{
@@ -165,11 +173,18 @@ pub(crate) async fn add_backup_keys_for_room_route(
 	for (session_id, key_data) in &body.sessions {
 		services
 			.key_backups
-			.add_key(body.sender_user(), &body.version, &body.room_id, session_id, key_data)
+			.add_key(
+				body.identity.sender_user(),
+				&body.version,
+				&body.room_id,
+				session_id,
+				key_data,
+			)
 			.await?;
 	}
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(add_backup_keys_for_room::v3::Response::new(etag, count))
 }
@@ -188,7 +203,7 @@ pub(crate) async fn add_backup_keys_for_session_route(
 ) -> Result<add_backup_keys_for_session::v3::Response> {
 	if services
 		.key_backups
-		.get_latest_backup_version(body.sender_user())
+		.get_latest_backup_version(body.identity.sender_user())
 		.await
 		.is_ok_and(|version| version != body.version)
 	{
@@ -201,7 +216,7 @@ pub(crate) async fn add_backup_keys_for_session_route(
 	let mut ok_to_replace = true;
 	if let Some(old_key) = &services
 		.key_backups
-		.get_session(body.sender_user(), &body.version, &body.room_id, &body.session_id)
+		.get_session(body.identity.sender_user(), &body.version, &body.room_id, &body.session_id)
 		.await
 		.ok()
 	{
@@ -260,7 +275,7 @@ pub(crate) async fn add_backup_keys_for_session_route(
 		services
 			.key_backups
 			.add_key(
-				body.sender_user(),
+				body.identity.sender_user(),
 				&body.version,
 				&body.room_id,
 				&body.session_id,
@@ -269,7 +284,8 @@ pub(crate) async fn add_backup_keys_for_session_route(
 			.await?;
 	}
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(add_backup_keys_for_session::v3::Response::new(etag, count))
 }
@@ -283,7 +299,7 @@ pub(crate) async fn get_backup_keys_route(
 ) -> Result<get_backup_keys::v3::Response> {
 	let rooms = services
 		.key_backups
-		.get_all(body.sender_user(), &body.version)
+		.get_all(body.identity.sender_user(), &body.version)
 		.await;
 
 	Ok(get_backup_keys::v3::Response::new(rooms))
@@ -298,7 +314,7 @@ pub(crate) async fn get_backup_keys_for_room_route(
 ) -> Result<get_backup_keys_for_room::v3::Response> {
 	let sessions = services
 		.key_backups
-		.get_room(body.sender_user(), &body.version, &body.room_id)
+		.get_room(body.identity.sender_user(), &body.version, &body.room_id)
 		.await;
 
 	Ok(get_backup_keys_for_room::v3::Response::new(sessions))
@@ -313,7 +329,7 @@ pub(crate) async fn get_backup_keys_for_session_route(
 ) -> Result<get_backup_keys_for_session::v3::Response> {
 	let key_data = services
 		.key_backups
-		.get_session(body.sender_user(), &body.version, &body.room_id, &body.session_id)
+		.get_session(body.identity.sender_user(), &body.version, &body.room_id, &body.session_id)
 		.await
 		.map_err(|_| {
 			err!(Request(NotFound(debug_error!("Backup key not found for this user's session."))))
@@ -331,10 +347,11 @@ pub(crate) async fn delete_backup_keys_route(
 ) -> Result<delete_backup_keys::v3::Response> {
 	services
 		.key_backups
-		.delete_all_keys(body.sender_user(), &body.version)
+		.delete_all_keys(body.identity.sender_user(), &body.version)
 		.await;
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(delete_backup_keys::v3::Response::new(etag, count))
 }
@@ -348,10 +365,11 @@ pub(crate) async fn delete_backup_keys_for_room_route(
 ) -> Result<delete_backup_keys_for_room::v3::Response> {
 	services
 		.key_backups
-		.delete_room_keys(body.sender_user(), &body.version, &body.room_id)
+		.delete_room_keys(body.identity.sender_user(), &body.version, &body.room_id)
 		.await;
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(delete_backup_keys_for_room::v3::Response::new(etag, count))
 }
@@ -365,10 +383,16 @@ pub(crate) async fn delete_backup_keys_for_session_route(
 ) -> Result<delete_backup_keys_for_session::v3::Response> {
 	services
 		.key_backups
-		.delete_room_key(body.sender_user(), &body.version, &body.room_id, &body.session_id)
+		.delete_room_key(
+			body.identity.sender_user(),
+			&body.version,
+			&body.room_id,
+			&body.session_id,
+		)
 		.await;
 
-	let (count, etag) = get_count_etag(&services, body.sender_user(), &body.version).await;
+	let (count, etag) =
+		get_count_etag(&services, body.identity.sender_user(), &body.version).await;
 
 	Ok(delete_backup_keys_for_session::v3::Response::new(etag, count))
 }

src/api/client/capabilities.rs

@@ -48,11 +48,7 @@ pub(crate) async fn get_capabilities_route(
 		json!({"enabled": services.config.forget_forced_upon_leave}),
 	)?;
 
-	if services
-		.users
-		.is_admin(body.sender_user.as_ref().unwrap())
-		.await
-	{
+	if services.users.is_admin(body.identity.sender_user()).await {
 		// Advertise suspension API
 		capabilities.set("uk.timedout.msc4323", json!({"suspend": true, "lock": false}))?;
 	}

src/api/client/context.rs

@@ -37,8 +37,8 @@ pub(crate) async fn get_context_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_context::v3::Request>,
 ) -> Result<get_context::v3::Response> {
-	let sender = body.sender();
-	let (sender_user, sender_device) = sender;
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.sender_device();
 	let room_id = &body.room_id;
 	let event_id = &body.event_id;
 	let filter = &body.filter;
@@ -143,7 +143,7 @@ pub(crate) async fn get_context_route(
 
 	let lazy_loading_context = lazy_loading::Context {
 		user_id: sender_user,
-		device_id: Some(sender_device),
+		device_id: sender_device,
 		room_id,
 		token: Some(base_count.into_unsigned()),
 		options: Some(&filter.lazy_load_options),

src/api/client/dehydrated_device.rs

@@ -25,16 +25,11 @@ pub(crate) async fn put_dehydrated_device_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<put_dehydrated_device::Request>,
 ) -> Result<put_dehydrated_device::Response> {
-	let sender_user = body
-		.sender_user
-		.as_deref()
-		.expect("AccessToken authentication required");
-
-	let device_id = body.body.device_id.clone();
+	let device_id = body.device_id.clone();
 
 	services
 		.users
-		.set_dehydrated_device(sender_user, body.body)
+		.set_dehydrated_device(body.identity.sender_user(), body.body)
 		.await?;
 
 	Ok(put_dehydrated_device::Response::new(device_id))
@@ -49,7 +44,7 @@ pub(crate) async fn delete_dehydrated_device_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<delete_dehydrated_device::Request>,
 ) -> Result<delete_dehydrated_device::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let device_id = services.users.get_dehydrated_device_id(sender_user).await?;
 
@@ -67,7 +62,7 @@ pub(crate) async fn get_dehydrated_device_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_dehydrated_device::Request>,
 ) -> Result<get_dehydrated_device::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let device = services.users.get_dehydrated_device(sender_user).await?;
 
@@ -83,7 +78,7 @@ pub(crate) async fn get_dehydrated_events_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_events::Request>,
 ) -> Result<get_events::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let device_id = &body.body.device_id;
 	let existing_id = services.users.get_dehydrated_device_id(sender_user).await;

src/api/client/device.rs

@@ -20,7 +20,7 @@ pub(crate) async fn get_devices_route(
 ) -> Result<get_devices::v3::Response> {
 	let devices: Vec<device::Device> = services
 		.users
-		.all_devices_metadata(body.sender_user())
+		.all_devices_metadata(body.identity.sender_user())
 		.collect()
 		.await;
 
@@ -36,7 +36,7 @@ pub(crate) async fn get_device_route(
 ) -> Result<get_device::v3::Response> {
 	let device = services
 		.users
-		.get_device_metadata(body.sender_user(), &body.body.device_id)
+		.get_device_metadata(body.identity.sender_user(), &body.body.device_id)
 		.await
 		.map_err(|_| err!(Request(NotFound("Device not found."))))?;
 
@@ -52,8 +52,8 @@ pub(crate) async fn update_device_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<update_device::v3::Request>,
 ) -> Result<update_device::v3::Response> {
-	let sender_user = body.sender_user();
-	let appservice = body.appservice_info.as_ref();
+	let sender_user = body.identity.sender_user();
+	let appservice = body.identity.appservice_info();
 
 	match services
 		.users
@@ -118,15 +118,14 @@ pub(crate) async fn delete_device_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_device::v3::Request>,
 ) -> Result<delete_device::v3::Response> {
-	let sender_user = body.sender_user();
-	let appservice = body.appservice_info.as_ref();
+	let sender_user = body.identity.sender_user();
 
 	// Appservices get to skip UIAA for this endpoint
-	if appservice.is_none() {
+	if let Some(sender_device) = body.identity.sender_device() {
 		// Prompt the user to confirm with their password using UIAA
 		let _ = services
 			.uiaa
-			.authenticate_password(&body.auth, sender_user, body.sender_device(), None)
+			.authenticate_password(&body.auth, sender_user, Some(sender_device), None)
 			.await?;
 	}
 
@@ -154,15 +153,14 @@ pub(crate) async fn delete_devices_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_devices::v3::Request>,
 ) -> Result<delete_devices::v3::Response> {
-	let sender_user = body.sender_user();
-	let appservice = body.appservice_info.as_ref();
+	let sender_user = body.identity.sender_user();
 
 	// Appservices get to skip UIAA for this endpoint
-	if appservice.is_none() {
+	if let Some(sender_device) = body.identity.sender_device() {
 		// Prompt the user to confirm with their password using UIAA
 		let _ = services
 			.uiaa
-			.authenticate_password(&body.auth, sender_user, body.sender_device(), None)
+			.authenticate_password(&body.auth, sender_user, Some(sender_device), None)
 			.await?;
 	}
 

src/api/client/directory.rs

@@ -112,7 +112,7 @@ pub(crate) async fn set_room_visibility_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<set_room_visibility::v3::Request>,
 ) -> Result<set_room_visibility::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if !services.rooms.metadata.exists(&body.room_id).await {
 		// Return 404 if the room doesn't exist
@@ -130,7 +130,7 @@ pub(crate) async fn set_room_visibility_route(
 		| room::Visibility::Public => {
 			if services.server.config.lockdown_public_room_directory
 				&& !services.users.is_admin(sender_user).await
-				&& body.appservice_info.is_none()
+				&& !body.identity.is_appservice()
 			{
 				info!(
 					"Non-admin user {sender_user} tried to publish {0} to the room directory \

src/api/client/filter.rs

@@ -15,7 +15,7 @@ pub(crate) async fn get_filter_route(
 ) -> Result<get_filter::v3::Response> {
 	services
 		.users
-		.get_filter(body.sender_user(), &body.filter_id)
+		.get_filter(body.identity.sender_user(), &body.filter_id)
 		.await
 		.map(get_filter::v3::Response::new)
 		.map_err(|_| err!(Request(NotFound("Filter not found."))))
@@ -30,7 +30,7 @@ pub(crate) async fn create_filter_route(
 ) -> Result<create_filter::v3::Response> {
 	let filter_id = services
 		.users
-		.create_filter(body.sender_user(), &body.filter);
+		.create_filter(body.identity.sender_user(), &body.filter);
 
 	Ok(create_filter::v3::Response::new(filter_id))
 }

src/api/client/keys.rs

@@ -41,7 +41,8 @@ pub(crate) async fn upload_keys_route(
 	State(services): State<crate::State>,
 	body: Ruma<upload_keys::v3::Request>,
 ) -> Result<upload_keys::v3::Response> {
-	let (sender_user, sender_device) = body.sender();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.expect_sender_device()?;
 
 	for (key_id, one_time_key) in &body.one_time_keys {
 		if one_time_key
@@ -154,7 +155,7 @@ pub(crate) async fn get_keys_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_keys::v3::Request>,
 ) -> Result<get_keys::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	get_keys_helper(
 		&services,
@@ -191,7 +192,7 @@ pub(crate) async fn upload_signing_keys_route(
 	State(services): State<crate::State>,
 	body: Ruma<upload_signing_keys::v3::Request>,
 ) -> Result<upload_signing_keys::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if uiaa_needed_to_upload_keys(
 		services,
@@ -207,7 +208,7 @@ pub(crate) async fn upload_signing_keys_route(
 			.authenticate_password(
 				&body.auth,
 				sender_user,
-				body.sender_device(),
+				body.identity.sender_device(),
 				Some(OAuthTicket::CrossSigningReset),
 			)
 			.await?;
@@ -292,7 +293,7 @@ pub(crate) async fn upload_signatures_route(
 		return Ok(upload_signatures::v3::Response::new());
 	}
 
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	for (user_id, keys) in &body.signed_keys {
 		for (key_id, key) in keys {
@@ -345,7 +346,7 @@ pub(crate) async fn get_key_changes_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_key_changes::v3::Request>,
 ) -> Result<get_key_changes::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let mut device_list_updates = HashSet::new();
 

src/api/client/media.rs

@@ -53,7 +53,7 @@ pub(crate) async fn create_content_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<create_content::v3::Request>,
 ) -> Result<create_content::v3::Response> {
-	let user = body.sender_user();
+	let user = body.identity.sender_user();
 	if services.users.is_suspended(user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
@@ -92,7 +92,7 @@ pub(crate) async fn get_content_thumbnail_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_content_thumbnail::v1::Request>,
 ) -> Result<get_content_thumbnail::v1::Response> {
-	let user = body.sender_user();
+	let user = body.identity.sender_user();
 
 	let dim = Dim::from_ruma(body.width, body.height, body.method.clone())?;
 	let mxc = Mxc {
@@ -142,7 +142,7 @@ pub(crate) async fn get_content_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_content::v1::Request>,
 ) -> Result<get_content::v1::Response> {
-	let user = body.sender_user();
+	let user = body.identity.sender_user();
 
 	let mxc = Mxc {
 		server_name: &body.server_name,
@@ -189,7 +189,7 @@ pub(crate) async fn get_content_as_filename_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_content_as_filename::v1::Request>,
 ) -> Result<get_content_as_filename::v1::Response> {
-	let user = body.sender_user();
+	let user = body.identity.sender_user();
 
 	let mxc = Mxc {
 		server_name: &body.server_name,
@@ -240,7 +240,7 @@ pub(crate) async fn get_media_preview_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_media_preview::v1::Request>,
 ) -> Result<get_media_preview::v1::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let url = &body.url;
 	let url = Url::parse(&body.url).map_err(|e| {

src/api/client/media_legacy.rs

@@ -56,7 +56,7 @@ pub(crate) async fn get_media_preview_legacy_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<get_media_preview::v3::Request>,
 ) -> Result<get_media_preview::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let url = &body.url;
 	let url = Url::parse(&body.url).map_err(|e| {

src/api/client/membership/ban.rs

@@ -15,7 +15,7 @@ pub(crate) async fn ban_user_route(
 	State(services): State<crate::State>,
 	body: Ruma<ban_user::v3::Request>,
 ) -> Result<ban_user::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if sender_user == body.user_id {
 		return Err!(Request(Forbidden("You cannot ban yourself.")));

src/api/client/membership/forget.rs

@@ -18,7 +18,7 @@ pub(crate) async fn forget_room_route(
 	State(services): State<crate::State>,
 	body: Ruma<forget_room::v3::Request>,
 ) -> Result<forget_room::v3::Response> {
-	let user_id = body.sender_user();
+	let user_id = body.identity.sender_user();
 	let room_id = &body.room_id;
 
 	let joined = services.rooms.state_cache.is_joined(user_id, room_id);

src/api/client/membership/invite.rs

@@ -29,7 +29,7 @@ pub(crate) async fn invite_user_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<invite_user::v3::Request>,
 ) -> Result<invite_user::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}

src/api/client/membership/join.rs

@@ -28,7 +28,7 @@ pub(crate) async fn join_room_by_id_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<join_room_by_id::v3::Request>,
 ) -> Result<join_room_by_id::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
@@ -97,7 +97,7 @@ pub(crate) async fn join_room_by_id_or_alias_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<join_room_by_id_or_alias::v3::Request>,
 ) -> Result<join_room_by_id_or_alias::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let body = &body.body;
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));

src/api/client/membership/kick.rs

@@ -15,7 +15,7 @@ pub(crate) async fn kick_user_route(
 	State(services): State<crate::State>,
 	body: Ruma<kick_user::v3::Request>,
 ) -> Result<kick_user::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}

src/api/client/membership/knock.rs

@@ -51,7 +51,7 @@ pub(crate) async fn knock_room_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<knock_room::v3::Request>,
 ) -> Result<knock_room::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let body = &body.body;
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));

src/api/client/membership/leave.rs

@@ -32,7 +32,7 @@ pub(crate) async fn leave_room_route(
 	State(services): State<crate::State>,
 	body: Ruma<leave_room::v3::Request>,
 ) -> Result<leave_room::v3::Response> {
-	leave_room(&services, body.sender_user(), &body.room_id, body.reason.clone())
+	leave_room(&services, body.identity.sender_user(), &body.room_id, body.reason.clone())
 		.boxed()
 		.await
 		.map(|()| leave_room::v3::Response::new())

src/api/client/membership/members.rs

@@ -30,7 +30,7 @@ pub(crate) async fn get_member_events_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_member_events::v3::Request>,
 ) -> Result<get_member_events::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let membership = body.membership.as_ref();
 	let not_membership = body.not_membership.as_ref();
 
@@ -72,7 +72,7 @@ pub(crate) async fn joined_members_route(
 	if !services
 		.rooms
 		.state_accessor
-		.user_can_see_state_events(body.sender_user(), &body.room_id)
+		.user_can_see_state_events(body.identity.sender_user(), &body.room_id)
 		.await
 	{
 		return Err!(Request(Forbidden("You don't have permission to view this room.")));

src/api/client/membership/mod.rs

@@ -40,7 +40,7 @@ pub(crate) async fn joined_rooms_route(
 	let joined_rooms = services
 		.rooms
 		.state_cache
-		.rooms_joined(body.sender_user())
+		.rooms_joined(body.identity.sender_user())
 		.collect()
 		.await;
 

src/api/client/membership/unban.rs

@@ -14,7 +14,7 @@ pub(crate) async fn unban_user_route(
 	State(services): State<crate::State>,
 	body: Ruma<unban_user::v3::Request>,
 ) -> Result<unban_user::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}

src/api/client/message.rs

@@ -23,7 +23,7 @@ use conduwuit_service::{
 };
 use futures::{FutureExt, StreamExt, TryFutureExt, future::OptionFuture, pin_mut};
 use ruma::{
-	DeviceId, RoomId, UserId,
+	RoomId, UserId,
 	api::{
 		Direction,
 		client::{filter::RoomEventFilter, message::get_message_events},
@@ -37,7 +37,6 @@ use ruma::{
 	serde::Raw,
 };
 use ruminuwuity::invite_permission_config::FilterLevel;
-use tracing::warn;
 
 use crate::Ruma;
 
@@ -76,8 +75,8 @@ pub(crate) async fn get_message_events_route(
 	ClientIp(client_ip): ClientIp,
 	body: Ruma<get_message_events::v3::Request>,
 ) -> Result<get_message_events::v3::Response> {
-	let sender_user = body.sender_user();
-	let sender_device = body.sender_device.as_deref();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.sender_device();
 	let room_id = &body.room_id;
 	let filter = &body.filter;
 
@@ -158,17 +157,7 @@ pub(crate) async fn get_message_events_route(
 
 	let lazy_loading_context = lazy_loading::Context {
 		user_id: sender_user,
-		device_id: sender_device.or_else(|| {
-			if let Some(registration) = body.appservice_info.as_ref() {
-				Some(<&DeviceId>::from(registration.registration.id.as_str()))
-			} else {
-				warn!(
-					"No device_id provided and no appservice registration found, this should be \
-					 unreachable"
-				);
-				None
-			}
-		}),
+		device_id: sender_device,
 		room_id,
 		token: Some(from.into_unsigned()),
 		options: Some(&filter.lazy_load_options),

src/api/client/mutual_rooms.rs

@@ -15,7 +15,7 @@ pub(crate) async fn get_mutual_rooms_route(
 	State(services): State<crate::State>,
 	body: Ruma<mutual_rooms::unstable::Request>,
 ) -> Result<mutual_rooms::unstable::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if sender_user == body.user_id {
 		return Err!(Request(Unknown("You cannot request rooms in common with yourself.")));

src/api/client/openid.rs

@@ -16,7 +16,7 @@ pub(crate) async fn create_openid_token_route(
 	State(services): State<crate::State>,
 	body: Ruma<account::request_openid_token::v3::Request>,
 ) -> Result<account::request_openid_token::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if sender_user != body.user_id {
 		return Err!(Request(InvalidParam(

src/api/client/presence.rs

@@ -20,13 +20,19 @@ pub(crate) async fn set_presence_route(
 		return Err!(Request(Forbidden("Presence is disabled on this server")));
 	}
 
-	if body.sender_user() != body.user_id && body.appservice_info.is_none() {
+	if body.identity.sender_user() != body.user_id && !body.identity.is_appservice() {
 		return Err!(Request(InvalidParam("Not allowed to set presence of other users")));
 	}
 
 	services
 		.presence
-		.set_presence(body.sender_user(), &body.presence, None, None, body.status_msg.clone())
+		.set_presence(
+			body.identity.sender_user(),
+			&body.presence,
+			None,
+			None,
+			body.status_msg.clone(),
+		)
 		.await?;
 
 	Ok(set_presence::v3::Response::new())
@@ -49,7 +55,7 @@ pub(crate) async fn get_presence_route(
 	let has_shared_rooms = services
 		.rooms
 		.state_cache
-		.user_sees_user(body.sender_user(), &body.user_id)
+		.user_sees_user(body.identity.sender_user(), &body.user_id)
 		.await;
 
 	if has_shared_rooms {

src/api/client/profile.rs

@@ -51,9 +51,12 @@ pub(crate) async fn set_profile_field_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_profile_field::v3::Request>,
 ) -> Result<set_profile_field::v3::Response> {
-	if body.user_id != body.sender_user()
-		&& !(body.appservice_info.is_some()
-			|| services.admin.user_is_admin(body.sender_user()).await)
+	if body.user_id != body.identity.sender_user()
+		&& !(body.identity.is_appservice()
+			|| services
+				.admin
+				.user_is_admin(body.identity.sender_user())
+				.await)
 	{
 		return Err!(Request(Forbidden("You may not change other users' profile data.")));
 	}
@@ -72,9 +75,12 @@ pub(crate) async fn delete_profile_field_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_profile_field::v3::Request>,
 ) -> Result<delete_profile_field::v3::Response> {
-	if body.user_id != body.sender_user()
-		&& !(body.appservice_info.is_some()
-			|| services.admin.user_is_admin(body.sender_user()).await)
+	if body.user_id != body.identity.sender_user()
+		&& !(body.identity.is_appservice()
+			|| services
+				.admin
+				.user_is_admin(body.identity.sender_user())
+				.await)
 	{
 		return Err!(Request(Forbidden("You may not change other users' profile data.")));
 	}

src/api/client/push.rs

@@ -30,7 +30,7 @@ pub(crate) async fn get_pushrules_all_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_pushrules_all::v3::Request>,
 ) -> Result<get_pushrules_all::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let Some(content_value) = services
 		.account_data
@@ -101,7 +101,7 @@ pub(crate) async fn get_pushrules_global_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_pushrules_global_scope::v3::Request>,
 ) -> Result<get_pushrules_global_scope::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let Some(content_value) = services
 		.account_data
@@ -189,7 +189,7 @@ pub(crate) async fn get_pushrule_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_pushrule::v3::Request>,
 ) -> Result<get_pushrule::v3::Response> {
-	let sender_user = body.sender_user.as_ref().expect("user is authenticated");
+	let sender_user = body.identity.sender_user();
 
 	// remove old deprecated mentions push rules as per MSC4210
 	#[allow(deprecated)]
@@ -226,7 +226,7 @@ pub(crate) async fn set_pushrule_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_pushrule::v3::Request>,
 ) -> Result<set_pushrule::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let body = &body.body;
 	let mut account_data: PushRulesEvent = services
 		.account_data
@@ -282,7 +282,7 @@ pub(crate) async fn get_pushrule_actions_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_pushrule_actions::v3::Request>,
 ) -> Result<get_pushrule_actions::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	// remove old deprecated mentions push rules as per MSC4210
 	#[allow(deprecated)]
@@ -316,7 +316,7 @@ pub(crate) async fn set_pushrule_actions_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_pushrule_actions::v3::Request>,
 ) -> Result<set_pushrule_actions::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let mut account_data: PushRulesEvent = services
 		.account_data
@@ -349,7 +349,7 @@ pub(crate) async fn get_pushrule_enabled_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_pushrule_enabled::v3::Request>,
 ) -> Result<get_pushrule_enabled::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	// remove old deprecated mentions push rules as per MSC4210
 	#[allow(deprecated)]
@@ -383,7 +383,7 @@ pub(crate) async fn set_pushrule_enabled_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_pushrule_enabled::v3::Request>,
 ) -> Result<set_pushrule_enabled::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let mut account_data: PushRulesEvent = services
 		.account_data
@@ -416,7 +416,7 @@ pub(crate) async fn delete_pushrule_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_pushrule::v3::Request>,
 ) -> Result<delete_pushrule::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let mut account_data: PushRulesEvent = services
 		.account_data
@@ -458,7 +458,7 @@ pub(crate) async fn get_pushers_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_pushers::v3::Request>,
 ) -> Result<get_pushers::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	Ok(get_pushers::v3::Response::new(services.pusher.get_pushers(sender_user).await))
 }
@@ -472,11 +472,12 @@ pub(crate) async fn set_pushers_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_pusher::v3::Request>,
 ) -> Result<set_pusher::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.expect_sender_device()?;
 
 	services
 		.pusher
-		.set_pusher(sender_user, body.sender_device(), &body.action)
+		.set_pusher(sender_user, sender_device, &body.action)
 		.await?;
 
 	Ok(set_pusher::v3::Response::new())

src/api/client/read_marker.rs

@@ -26,7 +26,7 @@ pub(crate) async fn set_read_marker_route(
 	State(services): State<crate::State>,
 	body: Ruma<set_read_marker::v3::Request>,
 ) -> Result<set_read_marker::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if let Some(event) = &body.fully_read {
 		let fully_read_event = FullyReadEvent::new(FullyReadEventContent::new(event.to_owned()));
@@ -118,10 +118,10 @@ pub(crate) async fn create_receipt_route(
 	ClientIp(client_ip): ClientIp,
 	body: Ruma<create_receipt::v3::Request>,
 ) -> Result<create_receipt::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	services
 		.users
-		.update_device_last_seen(sender_user, body.sender_device.as_deref(), client_ip)
+		.update_device_last_seen(sender_user, body.identity.sender_device(), client_ip)
 		.await;
 
 	if matches!(

src/api/client/redact.rs

@@ -17,10 +17,10 @@ pub(crate) async fn redact_event_route(
 	ClientIp(client_ip): ClientIp,
 	body: Ruma<redact_event::v3::Request>,
 ) -> Result<redact_event::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	services
 		.users
-		.update_device_last_seen(sender_user, body.sender_device.as_deref(), client_ip)
+		.update_device_last_seen(sender_user, body.identity.sender_device(), client_ip)
 		.await;
 	let body = &body.body;
 	if services.users.is_suspended(sender_user).await? {

src/api/client/relations.rs

@@ -28,7 +28,7 @@ pub(crate) async fn get_relating_events_with_rel_type_and_event_type_route(
 ) -> Result<get_relating_events_with_rel_type_and_event_type::v1::Response> {
 	paginate_relations_with_filter(
 		&services,
-		body.sender_user(),
+		body.identity.sender_user(),
 		&body.room_id,
 		&body.event_id,
 		body.event_type.clone().into(),
@@ -56,7 +56,7 @@ pub(crate) async fn get_relating_events_with_rel_type_route(
 ) -> Result<get_relating_events_with_rel_type::v1::Response> {
 	paginate_relations_with_filter(
 		&services,
-		body.sender_user(),
+		body.identity.sender_user(),
 		&body.room_id,
 		&body.event_id,
 		None,
@@ -84,7 +84,7 @@ pub(crate) async fn get_relating_events_route(
 ) -> Result<get_relating_events::v1::Response> {
 	paginate_relations_with_filter(
 		&services,
-		body.sender_user(),
+		body.identity.sender_user(),
 		&body.room_id,
 		&body.event_id,
 		None,

src/api/client/report.rs

@@ -36,7 +36,7 @@ pub(crate) async fn report_room_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<report_room::v3::Request>,
 ) -> Result<report_room::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
@@ -92,7 +92,7 @@ pub(crate) async fn report_event_route(
 	body: Ruma<report_content::v3::Request>,
 ) -> Result<report_content::v3::Response> {
 	// user authentication
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
@@ -135,8 +135,8 @@ pub(crate) async fn report_user_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<report_user::v3::Request>,
 ) -> Result<report_user::v3::Response> {
-	// user authentication
-	let sender_user = body.sender_user.as_ref().expect("user is authenticated");
+	let sender_user = body.identity.sender_user();
+
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}

src/api/client/room/aliases.rs

@@ -15,7 +15,7 @@ pub(crate) async fn get_room_aliases_route(
 	State(services): State<crate::State>,
 	body: Ruma<aliases::v3::Request>,
 ) -> Result<aliases::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if !services
 		.rooms

src/api/client/room/create.rs

@@ -61,10 +61,10 @@ pub(crate) async fn create_room_route(
 ) -> Result<create_room::v3::Response> {
 	use create_room::v3::RoomPreset;
 
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if !services.globals.allow_room_creation()
-		&& body.appservice_info.is_none()
+		&& !body.identity.is_appservice()
 		&& !services.users.is_admin(sender_user).await
 	{
 		return Err!(Request(Forbidden("Room creation has been disabled.",)));
@@ -130,7 +130,7 @@ pub(crate) async fn create_room_route(
 	if body.visibility == room::Visibility::Public
 		&& services.server.config.lockdown_public_room_directory
 		&& !services.users.is_admin(sender_user).await
-		&& body.appservice_info.is_none()
+		&& !body.identity.is_appservice()
 	{
 		warn!(
 			"Non-admin user {sender_user} tried to publish {room_id:?} to the room directory \
@@ -186,7 +186,7 @@ pub(crate) async fn create_room_route(
 
 	let alias: Option<OwnedRoomAliasId> = match body.room_alias_name.as_ref() {
 		| Some(alias) =>
-			Some(room_alias_check(&services, alias, body.appservice_info.as_ref()).await?),
+			Some(room_alias_check(&services, alias, body.identity.appservice_info()).await?),
 		| _ => None,
 	};
 

src/api/client/room/event.rs

@@ -24,25 +24,25 @@ pub(crate) async fn get_room_event_route(
 	let visible = services
 		.rooms
 		.state_accessor
-		.user_can_see_event(body.sender_user(), room_id, event_id)
+		.user_can_see_event(body.identity.sender_user(), room_id, event_id)
 		.map(Ok);
 
 	let (mut event, visible) = try_join(event, visible).await?;
 
-	if !visible || is_ignored_pdu(services, &event, body.sender_user()).await? {
+	if !visible || is_ignored_pdu(services, &event, body.identity.sender_user()).await? {
 		return Err!(Request(Forbidden("You don't have permission to view this event.")));
 	}
 
 	if let Err(e) = services
 		.rooms
 		.pdu_metadata
-		.add_bundled_aggregations_to_pdu(body.sender_user(), &mut event)
+		.add_bundled_aggregations_to_pdu(body.identity.sender_user(), &mut event)
 		.await
 	{
 		debug_warn!("Failed to add bundled aggregations to event: {e}");
 	}
 
-	event.set_unsigned(body.sender_user.as_deref());
+	event.set_unsigned(Some(body.identity.sender_user()));
 
 	Ok(get_room_event::v3::Response::new(event.into_format()))
 }

src/api/client/room/initial_sync.rs

@@ -22,7 +22,7 @@ pub(crate) async fn room_initial_sync_route(
 	if !services
 		.rooms
 		.state_accessor
-		.user_can_see_state_events(body.sender_user(), room_id)
+		.user_can_see_state_events(body.identity.sender_user(), room_id)
 		.await
 	{
 		return Err!(Request(Forbidden("No room preview available.")));
@@ -31,7 +31,7 @@ pub(crate) async fn room_initial_sync_route(
 	let membership = services
 		.rooms
 		.state_cache
-		.user_membership(body.sender_user(), room_id)
+		.user_membership(body.identity.sender_user(), room_id)
 		.map(Ok);
 
 	let visibility = services.rooms.directory.visibility(room_id).map(Ok);
@@ -52,16 +52,14 @@ pub(crate) async fn room_initial_sync_route(
 		.pdus_rev(room_id, None)
 		.try_take(limit)
 		.and_then(async |mut pdu| {
-			pdu.1.set_unsigned(body.sender_user.as_deref());
-			if let Some(sender_user) = body.sender_user.as_deref() {
-				if let Err(e) = services
-					.rooms
-					.pdu_metadata
-					.add_bundled_aggregations_to_pdu(sender_user, &mut pdu.1)
-					.await
-				{
-					debug_warn!("Failed to add bundled aggregations: {e}");
-				}
+			pdu.1.set_unsigned(Some(body.identity.sender_user()));
+			if let Err(e) = services
+				.rooms
+				.pdu_metadata
+				.add_bundled_aggregations_to_pdu(body.identity.sender_user(), &mut pdu.1)
+				.await
+			{
+				debug_warn!("Failed to add bundled aggregations: {e}");
 			}
 			Ok(pdu)
 		})

src/api/client/room/summary.rs

@@ -4,7 +4,7 @@ use conduwuit::{Err, Result};
 use ruma::api::client::room::get_summary;
 use service::rooms::summary::Accessibility;
 
-use crate::Ruma;
+use crate::{Ruma, router::ClientIdentity};
 
 /// # `GET /_matrix/client/v1/room_summary/{roomIdOrAlias}`
 ///
@@ -28,7 +28,11 @@ pub(crate) async fn get_room_summary(
 	let summary = services
 		.rooms
 		.summary
-		.get_room_summary_for_user(body.sender_user.as_deref(), &room_id, &servers)
+		.get_room_summary_for_user(
+			body.identity.as_ref().map(ClientIdentity::sender_user),
+			&room_id,
+			&servers,
+		)
 		.await?;
 
 	match summary {

src/api/client/room/upgrade.rs

@@ -277,7 +277,7 @@ pub(crate) async fn upgrade_room_route(
 	State(services): State<crate::State>,
 	body: Ruma<upgrade_room::v3::Request>,
 ) -> Result<upgrade_room::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let (supported, forbid_unstable, is_unstable) = (
 		services.server.supported_room_version(&body.new_version),

src/api/client/search.rs

@@ -43,7 +43,7 @@ pub(crate) async fn search_events_route(
 	State(services): State<crate::State>,
 	body: Ruma<Request>,
 ) -> Result<Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let next_batch = body.next_batch.as_deref();
 
 	let mut result_categories = ResultCategories::new();

src/api/client/send.rs

@@ -22,16 +22,16 @@ pub(crate) async fn send_message_event_route(
 	ClientIp(client_ip): ClientIp,
 	body: Ruma<send_message_event::v3::Request>,
 ) -> Result<send_message_event::v3::Response> {
-	let sender_user = body.sender_user();
-	let sender_device = body.sender_device.as_deref();
-	let appservice_info = body.appservice_info.as_ref();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.sender_device();
+
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
 
 	services
 		.users
-		.update_device_last_seen(sender_user, body.sender_device.as_deref(), client_ip)
+		.update_device_last_seen(sender_user, sender_device, client_ip)
 		.await;
 
 	// Forbid m.room.encrypted if encryption is disabled
@@ -83,7 +83,11 @@ pub(crate) async fn send_message_event_route(
 				event_type: body.event_type.clone().into(),
 				content,
 				unsigned: Some(unsigned),
-				timestamp: appservice_info.and(body.timestamp),
+				timestamp: if body.identity.is_appservice() {
+					body.timestamp
+				} else {
+					None
+				},
 				..Default::default()
 			},
 			sender_user,

src/api/client/session.rs

@@ -157,7 +157,7 @@ pub(crate) async fn login_route(
 		}) => {
 			debug!("Got appservice login type");
 
-			let Some(ref info) = body.appservice_info else {
+			let Some(ref info) = body.identity else {
 				return Err!(Request(MissingToken("Missing appservice token.")));
 			};
 
@@ -265,12 +265,12 @@ pub(crate) async fn login_token_route(
 		return Err!(Request(Forbidden("Login via an existing session is not enabled")));
 	}
 
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	// Prompt the user to confirm with their password using UIAA
 	let _ = services
 		.uiaa
-		.authenticate_password(&body.auth, sender_user, body.sender_device(), None)
+		.authenticate_password(&body.auth, sender_user, body.identity.sender_device(), None)
 		.await?;
 
 	let login_token = utils::random_string(TOKEN_LENGTH);
@@ -297,7 +297,9 @@ pub(crate) async fn logout_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<logout::v3::Request>,
 ) -> Result<logout::v3::Response> {
-	let (sender_user, sender_device) = body.sender();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.expect_sender_device()?;
+
 	services
 		.users
 		.remove_device(sender_user, sender_device)
@@ -343,7 +345,7 @@ pub(crate) async fn logout_all_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<logout_all::v3::Request>,
 ) -> Result<logout_all::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	services
 		.users
 		.all_device_ids(sender_user)

src/api/client/space.rs

@@ -27,7 +27,7 @@ pub(crate) async fn get_hierarchy_route(
 		.rooms
 		.summary
 		.get_room_hierarchy_for_user(
-			body.sender_user(),
+			body.identity.sender_user(),
 			body.room_id.clone(),
 			max_depth,
 			body.suggested_only,

src/api/client/state.rs

@@ -38,10 +38,10 @@ pub(crate) async fn send_state_event_for_key_route(
 	ClientIp(ip): ClientIp,
 	body: Ruma<send_state_event::v3::Request>,
 ) -> Result<send_state_event::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	services
 		.users
-		.update_device_last_seen(sender_user, body.sender_device.as_deref(), ip)
+		.update_device_last_seen(sender_user, body.identity.sender_device(), ip)
 		.await;
 
 	if services.users.is_suspended(sender_user).await? {
@@ -55,7 +55,7 @@ pub(crate) async fn send_state_event_for_key_route(
 		&body.event_type,
 		&body.body.body,
 		&body.state_key,
-		if body.appservice_info.is_some() {
+		if body.identity.is_appservice() {
 			body.timestamp
 		} else {
 			None
@@ -91,7 +91,7 @@ pub(crate) async fn get_state_events_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_state_events::v3::Request>,
 ) -> Result<get_state_events::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if !services
 		.rooms
@@ -125,7 +125,7 @@ pub(crate) async fn get_state_event_for_key_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_state_event_for_key::v3::Request>,
 ) -> Result<get_state_event_for_key::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	if !services
 		.rooms

src/api/client/sync/mod.rs

@@ -48,13 +48,6 @@ async fn load_timeline(
 	ending_count: Option<PduCount>,
 	limit: usize,
 ) -> Result<TimelinePdus> {
-	if let (Some(starting_count), Some(ending_count)) = (starting_count, ending_count) {
-		debug_assert!(
-			starting_count <= ending_count,
-			"starting count {starting_count} > ending count {ending_count}"
-		);
-	}
-
 	let mut pdu_stream = match starting_count {
 		| Some(starting_count) => {
 			let last_timeline_count = services

src/api/client/sync/v3/joined.rs

@@ -38,7 +38,6 @@ use ruma::{
 	uint,
 };
 use service::{account_data::AnyRawAccountDataEvent, rooms::short::ShortStateHash};
-use tokio::pin;
 
 use super::{load_timeline, share_encrypted_room};
 use crate::client::{
@@ -97,19 +96,12 @@ pub(super) async fn load_joined_room(
 		);
 	}
 
-	let state_events =
-		StateEvents::with_events(state_events.into_iter().map(Event::into_format).collect());
-
 	let joined_room = assign!(JoinedRoom::new(), {
 		account_data,
 		summary: summary.unwrap_or_default(),
 		unread_notifications: notification_counts.unwrap_or_default(),
 		timeline,
-		state: if sync_context.use_state_after {
-			RoomState::After(state_events)
-		} else {
-			RoomState::Before(state_events)
-		},
+		state: RoomState::Before(StateEvents::with_events(state_events.into_iter().map(Event::into_format).collect())),
 		ephemeral,
 		unread_thread_notifications: BTreeMap::new(),
 	});
@@ -352,7 +344,7 @@ struct ShortStateHashes {
 #[tracing::instrument(level = "debug", skip_all)]
 async fn fetch_shortstatehashes(
 	services: &Services,
-	SyncContext { last_sync_end_count, .. }: SyncContext<'_>,
+	SyncContext { last_sync_end_count, current_count, .. }: SyncContext<'_>,
 	room_id: &RoomId,
 ) -> Result<ShortStateHashes> {
 	// the room state currently.
@@ -362,41 +354,46 @@ async fn fetch_shortstatehashes(
 		.rooms
 		.state
 		.get_room_shortstatehash(room_id)
-		.map_err(|_| err!(Database(error!("Room {room_id} has no state"))))
-		.await?;
+		.map_err(|_| err!(Database(error!("Room {room_id} has no state"))));
 
-	// The room state as of the end of the last sync.
-	// This will be None if we are doing an initial sync.
+	// the room state as of the end of the last sync.
+	// this will be None if we are doing an initial sync or if we just joined this
+	// room.
 	let last_sync_end_shortstatehash =
-		OptionFuture::from(last_sync_end_count.map(async |last_sync_end_count| {
-			pin! {
-				let pdus = services
-					.rooms
-					.timeline
-					.pdus(room_id, Some(PduCount::Normal(last_sync_end_count)))
-					.ignore_err();
-			}
-
-			match pdus.next().await {
-				| Some((_, pdu_after_last_sync_end)) => {
-					trace!(?pdu_after_last_sync_end.event_id, "pdu at last sync end");
-
-					services
-						.rooms
-						.state_accessor
-						.pdu_shortstatehash(&pdu_after_last_sync_end.event_id)
-						.await
-						.map_err(|err| err!("Last sync end PDU has no shortstatehash: {err}"))
-				},
-				| None => {
-					// No events have been sent since the last sync, or we just joined this room,
-					// so the state then is the same as the state now
-					Ok(current_shortstatehash)
-				},
-			}
+		OptionFuture::from(last_sync_end_count.map(|last_sync_end_count| {
+			// look up the shortstatehash saved by the last sync's call to
+			// `associate_token_shortstatehash`
+			services
+				.rooms
+				.user
+				.get_token_shortstatehash(room_id, last_sync_end_count)
+				.inspect_err(move |_| {
+					debug_warn!(
+						token = last_sync_end_count,
+						"Room has no shortstatehash for this token"
+					);
+				})
+				.ok()
 		}))
-		.await
-		.transpose()?;
+		.map(Option::flatten)
+		.map(Ok);
+
+	let (current_shortstatehash, last_sync_end_shortstatehash) =
+		try_join(current_shortstatehash, last_sync_end_shortstatehash).await?;
+
+	/*
+	associate the `current_count` with the `current_shortstatehash`, so we can
+	use it on the next sync as the `last_sync_end_shortstatehash`.
+
+	TODO: the table written to by this call grows extremely fast, gaining one new entry for each
+	joined room on _every single sync request_. we need to find a better way to remember the shortstatehash
+	between syncs.
+	*/
+	services
+		.rooms
+		.user
+		.associate_token_shortstatehash(room_id, current_count, current_shortstatehash)
+		.await;
 
 	Ok(ShortStateHashes {
 		current_shortstatehash,
@@ -455,7 +452,6 @@ async fn build_state_events(
 		syncing_user,
 		last_sync_end_count,
 		full_state,
-		use_state_after,
 		..
 	} = sync_context;
 
@@ -464,28 +460,32 @@ async fn build_state_events(
 		last_sync_end_shortstatehash,
 	} = shortstatehashes;
 
-	let timeline_start_shortstatehash = if let Some((count, pdu)) = timeline.pdus.front() {
-		if matches!(count, PduCount::Backfilled(_)) {
-			// We don't have shortstatehashes for backfilled PDUs, the best we can
-			// do is to use the current state
-			current_shortstatehash
-		} else {
-			services
+	// the spec states that the `state` property only includes state events up to
+	// the beginning of the timeline, so we determine the state of the syncing room
+	// as of the first timeline event. NOTE: this explanation is not entirely
+	// accurate; see the implementation of `build_state_incremental`.
+	let timeline_start_shortstatehash = async {
+		if let Some((_, pdu)) = timeline.pdus.front() {
+			if let Ok(shortstatehash) = services
 				.rooms
 				.state_accessor
 				.pdu_shortstatehash(&pdu.event_id)
 				.await
-				.map_err(|err| err!("Timeline start has no shortstatehash: {err}"))?
+			{
+				return shortstatehash;
+			}
 		}
-	} else {
-		// if the timeline is empty there can't possibly be any changes to the state
-		return Ok(vec![]);
+
+		current_shortstatehash
 	};
 
 	// the user IDs of members whose membership needs to be sent to the client, if
 	// lazy-loading is enabled.
 	let lazily_loaded_members =
-		prepare_lazily_loaded_members(services, sync_context, room_id, timeline.senders()).await;
+		prepare_lazily_loaded_members(services, sync_context, room_id, timeline.senders());
+
+	let (timeline_start_shortstatehash, lazily_loaded_members) =
+		join(timeline_start_shortstatehash, lazily_loaded_members).await;
 
 	// compute the state delta between the previous sync and this sync.
 	match (last_sync_end_count, last_sync_end_shortstatehash) {
@@ -494,15 +494,16 @@ async fn build_state_events(
 		is Some (meaning the syncing user didn't just join this room for the first time ever), and `full_state` is false,
 		then use `build_state_incremental`.
 		*/
-		| (Some(_), Some(last_sync_end_shortstatehash)) if !full_state =>
+		| (Some(last_sync_end_count), Some(last_sync_end_shortstatehash)) if !full_state =>
 			build_state_incremental(
 				services,
 				syncing_user,
+				room_id,
+				PduCount::Normal(last_sync_end_count),
 				last_sync_end_shortstatehash,
 				timeline_start_shortstatehash,
 				current_shortstatehash,
 				timeline,
-				use_state_after,
 				lazily_loaded_members.as_ref(),
 			)
 			.boxed()
@@ -517,8 +518,6 @@ async fn build_state_events(
 				services,
 				syncing_user,
 				timeline_start_shortstatehash,
-				current_shortstatehash,
-				use_state_after,
 				lazily_loaded_members.as_ref(),
 			)
 			.boxed()
@@ -599,25 +598,23 @@ async fn check_joined_since_last_sync(
 	ShortStateHashes { last_sync_end_shortstatehash, .. }: ShortStateHashes,
 	SyncContext { syncing_user, .. }: SyncContext<'_>,
 ) -> Result<bool> {
-	let Some(last_sync_end_shortstatehash) = last_sync_end_shortstatehash else {
-		// For initial syncs always return false, since there's no "last sync" for the
-		// user to have joined since.
-		return Ok(false);
+	// fetch the syncing user's membership event during the last sync.
+	// this will be None if `previous_sync_end_shortstatehash` is None.
+	let membership_during_previous_sync = match last_sync_end_shortstatehash {
+		| Some(last_sync_end_shortstatehash) => services
+			.rooms
+			.state_accessor
+			.state_get_content(
+				last_sync_end_shortstatehash,
+				&StateEventType::RoomMember,
+				syncing_user.as_str(),
+			)
+			.await
+			.inspect_err(|_| debug_warn!("User has no previous membership"))
+			.ok(),
+		| None => None,
 	};
 
-	// Fetch the syncing user's membership event during the last sync.
-	let membership_during_previous_sync = services
-		.rooms
-		.state_accessor
-		.state_get_content(
-			last_sync_end_shortstatehash,
-			&StateEventType::RoomMember,
-			syncing_user.as_str(),
-		)
-		.await
-		.inspect_err(|_| debug_warn!("User has no previous membership"))
-		.ok();
-
 	// TODO: If the requesting user got state-reset out of the room, this
 	// will be `true` when it shouldn't be. this function should never be called
 	// in that situation, but it may be if the membership cache didn't get updated.

src/api/client/sync/v3/left.rs

@@ -181,9 +181,6 @@ pub(super) async fn load_left_room(
 		.collect::<Vec<_>>()
 		.await;
 
-	let state_events =
-		StateEvents::with_events(state_events.into_iter().map(Event::into_format).collect());
-
 	Ok(Some(assign!(LeftRoom::new(), {
 		account_data: RoomAccountData::new(),
 		timeline: assign!(Timeline::new(), {
@@ -191,11 +188,7 @@ pub(super) async fn load_left_room(
 			prev_batch: Some(current_count.to_string()),
 			events: raw_timeline_pdus,
 		}),
-		state: if sync_context.use_state_after {
-			State::After(state_events)
-		} else {
-			State::Before(state_events)
-		},
+		state: State::Before(StateEvents::with_events(state_events.into_iter().map(Event::into_format).collect())),
 	})))
 }
 
@@ -271,8 +264,6 @@ async fn build_left_state_and_timeline(
 		services,
 		syncing_user,
 		timeline_start_shortstatehash,
-		leave_shortstatehash,
-		sync_context.use_state_after,
 		lazily_loaded_members.as_ref(),
 	)
 	.await?;

src/api/client/sync/v3/mod.rs

@@ -11,11 +11,12 @@ use std::{
 use axum::extract::State;
 use axum_client_ip::ClientIp;
 use conduwuit::{
-	Err, Result, at, error, extract_variant,
+	Err, Result, at, extract_variant,
 	utils::{
 		ReadyExt, TryFutureExtExt,
 		stream::{BroadbandExt, Tools, WidebandExt},
 	},
+	warn,
 };
 use conduwuit_service::Services;
 use futures::{FutureExt, StreamExt, TryFutureExt, future::OptionFuture};
@@ -109,9 +110,6 @@ struct SyncContext<'a> {
 	/// The sync filter, which the client uses to specify what data should be
 	/// included in the sync response.
 	filter: &'a FilterDefinition,
-	/// Whether the state at the end of the timeline should be used when
-	/// calculating state diffs for sync.
-	use_state_after: bool,
 }
 
 impl<'a> SyncContext<'a> {
@@ -183,7 +181,8 @@ pub(crate) async fn sync_events_route(
 	ClientIp(client_ip): ClientIp,
 	body: Ruma<sync_events::v3::Request>,
 ) -> Result<sync_events::v3::Response> {
-	let (sender_user, sender_device) = body.sender();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.expect_sender_device()?;
 
 	// Presence update
 	if services.config.allow_local_presence {
@@ -227,7 +226,8 @@ pub(crate) async fn build_sync_events(
 	services: &Services,
 	body: &Ruma<sync_events::v3::Request>,
 ) -> Result<sync_events::v3::Response> {
-	let (syncing_user, syncing_device) = body.sender();
+	let syncing_user = body.identity.sender_user();
+	let syncing_device = body.identity.sender_device().expect("should have a device");
 
 	let current_count = services.globals.current_count()?;
 
@@ -263,7 +263,6 @@ pub(crate) async fn build_sync_events(
 		current_count,
 		full_state,
 		filter: &filter,
-		use_state_after: body.use_state_after,
 	};
 
 	let joined_rooms = services
@@ -276,7 +275,7 @@ pub(crate) async fn build_sync_events(
 			match joined_room {
 				| Ok((room, updates)) => Some((room_id, room, updates)),
 				| Err(err) => {
-					error!(?err, %room_id, "error loading joined room");
+					warn!(?err, %room_id, "error loading joined room");
 					None
 				},
 			}
@@ -305,7 +304,7 @@ pub(crate) async fn build_sync_events(
 				| Ok(Some(left_room)) => Some((room_id, left_room)),
 				| Ok(None) => None,
 				| Err(err) => {
-					error!(?err, %room_id, "error loading joined room");
+					warn!(?err, %room_id, "error loading joined room");
 					None
 				},
 			}

src/api/client/sync/v3/state.rs

@@ -1,8 +1,11 @@
-use std::collections::HashSet;
+use std::{collections::BTreeSet, ops::ControlFlow};
 
 use conduwuit::{
-	Result, at,
-	matrix::{Event, pdu::PduEvent},
+	Result, at, is_equal_to,
+	matrix::{
+		Event,
+		pdu::{PduCount, PduEvent},
+	},
 	utils::{
 		BoolExt, IterStream, ReadyExt, TryFutureExtExt,
 		stream::{BroadbandExt, TryIgnore},
@@ -13,7 +16,9 @@ use conduwuit_service::{
 	rooms::{lazy_loading::MemberSet, short::ShortStateHash},
 };
 use futures::{FutureExt, StreamExt};
-use ruma::{OwnedEventId, UserId, events::StateEventType};
+use itertools::Itertools;
+use ruma::{OwnedEventId, RoomId, UserId, events::StateEventType};
+use service::rooms::short::ShortEventId;
 use tracing::trace;
 
 use crate::client::TimelinePdus;
@@ -34,19 +39,13 @@ pub(super) async fn build_state_initial(
 	services: &Services,
 	sender_user: &UserId,
 	timeline_start_shortstatehash: ShortStateHash,
-	timeline_end_shortstatehash: ShortStateHash,
-	use_state_after: bool,
 	lazily_loaded_members: Option<&MemberSet>,
 ) -> Result<Vec<PduEvent>> {
 	// load the keys and event IDs of the state events at the start of the timeline
 	let (shortstatekeys, event_ids): (Vec<_>, Vec<_>) = services
 		.rooms
 		.state_accessor
-		.state_full_ids(if use_state_after {
-			timeline_end_shortstatehash
-		} else {
-			timeline_start_shortstatehash
-		})
+		.state_full_ids(timeline_start_shortstatehash)
 		.unzip()
 		.await;
 
@@ -93,34 +92,82 @@ pub(super) async fn build_state_initial(
 pub(super) async fn build_state_incremental<'a>(
 	services: &Services,
 	sender_user: &'a UserId,
+	room_id: &RoomId,
+	last_sync_end_count: PduCount,
 	last_sync_end_shortstatehash: ShortStateHash,
 	timeline_start_shortstatehash: ShortStateHash,
 	timeline_end_shortstatehash: ShortStateHash,
 	timeline: &TimelinePdus,
-	use_state_after: bool,
 	lazily_loaded_members: Option<&'a MemberSet>,
 ) -> Result<Vec<PduEvent>> {
-	let mut state_event_ids: HashSet<OwnedEventId> = HashSet::new();
+	/*
+	NB: a limited sync is one where `timeline.limited == true`. Synapse calls this a "gappy" sync internally.
 
-	trace!(
-		%use_state_after,
-		%last_sync_end_shortstatehash,
-		%timeline_start_shortstatehash,
-		%timeline_end_shortstatehash,
-		"computing state for incremental sync"
-	);
+	The algorithm implemented in this function is, currently, quite different from the algorithm vaguely described
+	by the Matrix specification. This is because the specification's description of the `state` property does not accurately
+	reflect how Synapse behaves, and therefore how client SDKs behave. Notable differences include:
+	1. We do not compute the delta using the naive approach of "every state event from the end of the last sync
+	   up to the start of this sync's timeline". see below for details.
+	2. If lazy-loading is enabled, we include lazily-loaded membership events. The specific users to include are determined
+	   elsewhere and supplied to this function in the `lazily_loaded_members` parameter.
+	*/
 
-	// Fetch lazy-loaded membership events if lazy-loading is enabled
-	if let Some(lazily_loaded_members) = lazily_loaded_members
-		&& !lazily_loaded_members.is_empty()
-	{
-		trace!("including lazy membership events for members: {:?}", lazily_loaded_members);
+	/*
+	the `state` property of an incremental sync which isn't limited are _usually_ empty.
+	(note: the specification says that the `state` property is _always_ empty for limited syncs, which is incorrect.)
+	however, if an event in the timeline (`timeline.pdus`) merges a split in the room's DAG (i.e. has multiple `prev_events`),
+	the state at the _end_ of the timeline may include state events which were merged in and don't exist in the state
+	at the _start_ of the timeline. because this is uncommon, we check here to see if any events in the timeline
+	merged a split in the DAG.
 
-		services
+	see: https://github.com/element-hq/synapse/issues/16941
+	*/
+
+	let timeline_is_linear = timeline.pdus.is_empty() || {
+		let last_pdu_of_last_sync = services
 			.rooms
-			.short
-			.multi_get_eventid_from_short::<'_, OwnedEventId, _>(
-				lazily_loaded_members
+			.timeline
+			.pdus_rev(room_id, Some(last_sync_end_count.saturating_add(1)))
+			.boxed()
+			.next()
+			.await
+			.transpose()
+			.expect("last sync should have had some PDUs")
+			.map(at!(1));
+
+		// make sure the prev_events of each pdu in the timeline refer only to the
+		// previous pdu
+		timeline
+			.pdus
+			.iter()
+			.try_fold(last_pdu_of_last_sync.map(|pdu| pdu.event_id), |prev_event_id, (_, pdu)| {
+				if let Ok(pdu_prev_event_id) = pdu.prev_events.iter().exactly_one() {
+					if prev_event_id
+						.as_ref()
+						.is_none_or(is_equal_to!(pdu_prev_event_id))
+					{
+						return ControlFlow::Continue(Some(pdu_prev_event_id.to_owned()));
+					}
+				}
+
+				trace!(
+					"pdu {:?} has split prev_events (expected {:?}): {:?}",
+					pdu.event_id, prev_event_id, pdu.prev_events
+				);
+				ControlFlow::Break(())
+			})
+			.is_continue()
+	};
+
+	if timeline_is_linear && !timeline.limited {
+		// if there are no splits in the DAG and the timeline isn't limited, then
+		// `state` will always be empty unless lazy loading is enabled.
+
+		if let Some(lazily_loaded_members) = lazily_loaded_members {
+			if !timeline.pdus.is_empty() {
+				// lazy loading is enabled, so we return the membership events which were
+				// requested by the caller.
+				let lazy_membership_events: Vec<_> = lazily_loaded_members
 					.iter()
 					.stream()
 					.broad_filter_map(|user_id| async move {
@@ -131,24 +178,71 @@ pub(super) async fn build_state_incremental<'a>(
 						services
 							.rooms
 							.state_accessor
-							.state_get_shortid(
+							.state_get(
 								timeline_start_shortstatehash,
 								&StateEventType::RoomMember,
 								user_id.as_str(),
 							)
 							.ok()
 							.await
-					}),
-			)
-			.ignore_err()
-			.ready_for_each(|event_id| {
-				state_event_ids.insert(event_id);
-			})
-			.await;
+					})
+					.collect()
+					.await;
+
+				if !lazy_membership_events.is_empty() {
+					trace!(
+						"syncing lazy membership events for members: {:?}",
+						lazy_membership_events
+							.iter()
+							.map(|pdu| pdu.state_key().unwrap())
+							.collect::<Vec<_>>()
+					);
+				}
+				return Ok(lazy_membership_events);
+			}
+		}
+
+		// lazy loading is disabled, `state` is empty.
+		return Ok(vec![]);
 	}
 
-	// Fetch the state events added since the last sync.
-	services
+	/*
+	at this point, either the timeline is `limited` or the DAG has a split in it. this necessitates
+	computing the incremental state (which may be empty).
+
+	NOTE: this code path does not use the `lazy_membership_events` parameter. any changes to membership will be included
+	in the incremental state. therefore, the incremental state may include "redundant" membership events,
+	which we do not filter out because A. the spec forbids lazy-load filtering if the timeline is `limited`,
+	and B. DAG splits which require sending extra membership state events are (probably) uncommon enough that
+	the performance penalty is acceptable.
+	*/
+
+	trace!(%timeline_is_linear, %timeline.limited, "computing state for incremental sync");
+
+	// fetch the shorteventids of state events in the timeline
+	let state_events_in_timeline: BTreeSet<ShortEventId> = services
+		.rooms
+		.short
+		.multi_get_or_create_shorteventid(timeline.pdus.iter().filter_map(|(_, pdu)| {
+			if pdu.state_key().is_some() {
+				Some(pdu.event_id.as_ref())
+			} else {
+				None
+			}
+		}))
+		.collect()
+		.await;
+
+	trace!("{} state events in timeline", state_events_in_timeline.len());
+
+	/*
+	fetch the state events which were added since the last sync.
+
+	specifically we fetch the difference between the state at the last sync and the state at the _end_
+	of the timeline, and then we filter out state events in the timeline itself using the shorteventids we fetched.
+	this is necessary to account for splits in the DAG, as explained above.
+	*/
+	let state_diff = services
 		.rooms
 		.short
 		.multi_get_eventid_from_short::<'_, OwnedEventId, _>(
@@ -158,29 +252,18 @@ pub(super) async fn build_state_incremental<'a>(
 				.state_added((last_sync_end_shortstatehash, timeline_end_shortstatehash))
 				.await?
 				.stream()
-				.map(at!(1)),
+				.ready_filter_map(|(_, shorteventid)| {
+					if state_events_in_timeline.contains(&shorteventid) {
+						None
+					} else {
+						Some(shorteventid)
+					}
+				}),
 		)
-		.ignore_err()
-		.ready_for_each(|event_id| {
-			state_event_ids.insert(event_id);
-		})
-		.await;
+		.ignore_err();
 
-	if !use_state_after {
-		// If state_after isn't enabled, filter out state events which also exist
-		// in the timeline. If splits exist in the DAG, this may not be exactly the same
-		// thing as the state diff ending at the start of the timeline, but Synapse
-		// also does this and it's technically more useful behavior anyway.
-		// See: https://github.com/element-hq/synapse/issues/16941
-
-		for (_, pdu) in &timeline.pdus {
-			state_event_ids.remove(pdu.event_id());
-		}
-	}
-
-	// Finally, fetch the PDU contents and collect them into a vec
-	let state_diff_pdus = state_event_ids
-		.stream()
+	// finally, fetch the PDU contents and collect them into a vec
+	let state_diff_pdus = state_diff
 		.broad_filter_map(|event_id| async move {
 			services
 				.rooms

src/api/client/sync/v5.rs

@@ -15,7 +15,7 @@ use conduwuit::{
 		BoolExt, FutureBoolExt, IterStream, ReadyExt, TryFutureExtExt,
 		future::ReadyEqExt,
 		math::{ruma_from_usize, usize_from_ruma},
-		stream::{TryIgnore, WidebandExt},
+		stream::WidebandExt,
 	},
 	warn,
 };
@@ -41,7 +41,6 @@ use ruma::{
 	uint,
 };
 use service::account_data::AnyRawAccountDataEvent;
-use tokio::pin;
 
 use super::share_encrypted_room;
 use crate::{
@@ -70,8 +69,8 @@ pub(crate) async fn sync_events_v5_route(
 	ClientIp(client_ip): ClientIp,
 	body: Ruma<sync_events::v5::Request>,
 ) -> Result<sync_events::v5::Response> {
-	let ref sender_user = body.sender_user().to_owned();
-	let ref sender_device = body.sender_device().to_owned();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.expect_sender_device()?;
 
 	services
 		.users
@@ -93,7 +92,7 @@ pub(crate) async fn sync_events_v5_route(
 		.and_then(|string| string.parse().ok())
 		.unwrap_or(0);
 
-	let snake_key = into_snake_key(sender_user.as_ref(), sender_device.as_str(), conn_id);
+	let snake_key = into_snake_key(sender_user, sender_device.as_str(), conn_id);
 
 	if globalsince != 0 && !services.sync.snake_connection_cached(&snake_key) {
 		return Err!(Request(UnknownPos(
@@ -858,27 +857,12 @@ where
 			continue;
 		};
 
-		let since_shortstatehash = async {
-			pin! {
-				let pdus_rev = services
-					.rooms
-					.timeline
-					.pdus_rev(room_id, Some(PduCount::Normal(globalsince.saturating_sub(1))))
-					.ignore_err();
-			}
-
-			let (_, pdu_at_last_sync_end) = pdus_rev.next().await?;
-
-			Some(
-				services
-					.rooms
-					.state_accessor
-					.pdu_shortstatehash(&pdu_at_last_sync_end.event_id)
-					.await
-					.expect("pdu should have a shortstatehash"),
-			)
-		}
-		.await;
+		let since_shortstatehash = services
+			.rooms
+			.user
+			.get_token_shortstatehash(room_id, globalsince)
+			.await
+			.ok();
 
 		let encrypted_room = services
 			.rooms

src/api/client/tag.rs

@@ -21,7 +21,7 @@ pub(crate) async fn update_tag_route(
 	State(services): State<crate::State>,
 	body: Ruma<create_tag::v3::Request>,
 ) -> Result<create_tag::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let mut tags_event = services
 		.account_data
@@ -56,7 +56,7 @@ pub(crate) async fn delete_tag_route(
 	State(services): State<crate::State>,
 	body: Ruma<delete_tag::v3::Request>,
 ) -> Result<delete_tag::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let mut tags_event = services
 		.account_data
@@ -88,7 +88,7 @@ pub(crate) async fn get_tags_route(
 	State(services): State<crate::State>,
 	body: Ruma<get_tags::v3::Request>,
 ) -> Result<get_tags::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 
 	let tags_event = services
 		.account_data

src/api/client/threads.rs

@@ -34,14 +34,14 @@ pub(crate) async fn get_threads_route(
 	let threads: Vec<(PduCount, PduEvent)> = services
 		.rooms
 		.threads
-		.threads_until(body.sender_user(), &body.room_id, from, &body.include)
+		.threads_until(body.identity.sender_user(), &body.room_id, from, &body.include)
 		.await?
 		.take(limit)
 		.filter_map(|(count, pdu)| async move {
 			services
 				.rooms
 				.state_accessor
-				.user_can_see_event(body.sender_user(), &body.room_id, &pdu.event_id)
+				.user_can_see_event(body.identity.sender_user(), &body.room_id, &pdu.event_id)
 				.await
 				.then_some((count, pdu))
 		})
@@ -49,7 +49,7 @@ pub(crate) async fn get_threads_route(
 			if let Err(e) = services
 				.rooms
 				.pdu_metadata
-				.add_bundled_aggregations_to_pdu(body.sender_user(), &mut pdu)
+				.add_bundled_aggregations_to_pdu(body.identity.sender_user(), &mut pdu)
 				.await
 			{
 				debug_warn!("Failed to add bundled aggregations to thread: {e}");

src/api/client/to_device.rs

@@ -22,8 +22,8 @@ pub(crate) async fn send_event_to_device_route(
 	State(services): State<crate::State>,
 	body: Ruma<send_event_to_device::v3::Request>,
 ) -> Result<send_event_to_device::v3::Response> {
-	let sender_user = body.sender_user();
-	let sender_device = body.sender_device.as_deref();
+	let sender_user = body.identity.sender_user();
+	let sender_device = body.identity.sender_device();
 
 	// Check if this is a new transaction id
 	if services

src/api/client/typing.rs

@@ -14,13 +14,13 @@ pub(crate) async fn create_typing_event_route(
 	body: Ruma<create_typing_event::v3::Request>,
 ) -> Result<create_typing_event::v3::Response> {
 	use create_typing_event::v3::Typing;
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	services
 		.users
-		.update_device_last_seen(sender_user, body.sender_device.as_deref(), ip)
+		.update_device_last_seen(sender_user, body.identity.sender_device(), ip)
 		.await;
 
-	if sender_user != body.user_id && body.appservice_info.is_none() {
+	if sender_user != body.user_id && !body.identity.is_appservice() {
 		return Err!(Request(Forbidden("You cannot update typing status of other users.")));
 	}
 

src/api/client/user_directory.rs

@@ -26,7 +26,7 @@ pub(crate) async fn search_users_route(
 	State(services): State<crate::State>,
 	body: Ruma<search_users::v3::Request>,
 ) -> Result<search_users::v3::Response> {
-	let sender_user = body.sender_user();
+	let sender_user = body.identity.sender_user();
 	let limit = usize::try_from(body.limit)
 		.map_or(LIMIT_DEFAULT, usize::from)
 		.min(LIMIT_MAX);

src/api/client/voip.rs

@@ -2,15 +2,13 @@ use std::time::{Duration, SystemTime};
 
 use axum::extract::State;
 use base64::{Engine as _, engine::general_purpose};
-use conduwuit::{Err, Result, utils};
+use conduwuit::{Err, Result};
 use hmac::{Hmac, KeyInit, Mac};
-use ruma::{SecondsSinceUnixEpoch, UserId, api::client::voip::get_turn_server_info};
+use ruma::{SecondsSinceUnixEpoch, api::client::voip::get_turn_server_info};
 use sha1::Sha1;
 
 use crate::Ruma;
 
-const RANDOM_USER_ID_LENGTH: usize = 10;
-
 type HmacSha1 = Hmac<Sha1>;
 
 /// # `GET /_matrix/client/r0/voip/turnServer`
@@ -35,15 +33,7 @@ pub(crate) async fn turn_server_route(
 		)
 		.expect("time is valid");
 
-		let user = body.sender_user.unwrap_or_else(|| {
-			UserId::parse_with_server_name(
-				utils::random_string(RANDOM_USER_ID_LENGTH).to_lowercase(),
-				&services.server.name,
-			)
-			.unwrap()
-		});
-
-		let username: String = format!("{}:{}", expiry.get(), user);
+		let username: String = format!("{}:{}", expiry.get(), body.identity.sender_user());
 
 		let mut mac = HmacSha1::new_from_slice(turn_secret.as_bytes())
 			.expect("HMAC can take key of any size");

src/api/router.rs

@@ -15,7 +15,7 @@ pub(super) use conduwuit_service::state::State;
 use http::{Uri, uri};
 
 use self::handler::RouterExt;
-pub(super) use self::{args::Args as Ruma, response::RumaResponse};
+pub(super) use self::{args::Args as Ruma, auth::ClientIdentity, response::RumaResponse};
 use crate::{admin, client, server};
 
 pub fn build(router: Router<State>, state: State) -> Router<State> {

src/api/router/args.rs

@@ -6,17 +6,14 @@ use axum::{
 	extract::{FromRequest, Path, Query},
 };
 use conduwuit::{Error, Result, err};
-use ruma::{
-	CanonicalJsonObject, DeviceId, OwnedDeviceId, OwnedServerName, OwnedUserId, ServerName,
-	UserId, api::IncomingRequest,
-};
+use ruma::{CanonicalJsonObject, api::IncomingRequest};
 use serde::Deserialize;
 
-use crate::{State, router::auth::CheckAuth, service::appservice::RegistrationInfo};
+use crate::{State, router::auth::CheckAuth};
 
 /// Query parameters needed to authenticate requests
 #[derive(Deserialize)]
-pub(super) struct AuthQueryParams {
+pub(crate) struct AuthQueryParams {
 	pub(super) user_id: Option<String>,
 	/// Device ID for appservice device masquerading (MSC3202/MSC4190).
 	/// Can be provided as `device_id` or `org.matrix.msc3202.device_id`.
@@ -25,67 +22,22 @@ pub(super) struct AuthQueryParams {
 }
 
 /// Extractor for Ruma request structs
-pub(crate) struct Args<T> {
+pub(crate) struct Args<R: IncomingRequest<Authentication: CheckAuth> + Send + Sync + 'static> {
 	/// Request struct body
-	pub(crate) body: T,
+	pub(crate) body: R,
 
-	/// Federation server authentication: X-Matrix origin
-	/// None when not a federation server.
-	pub(crate) origin: Option<OwnedServerName>,
-
-	/// Local user authentication: user_id.
-	/// None when not an authenticated local user.
-	pub(crate) sender_user: Option<OwnedUserId>,
-
-	/// Local user authentication: device_id.
-	/// None when not an authenticated local user or no device.
-	pub(crate) sender_device: Option<OwnedDeviceId>,
-
-	/// Appservice authentication; registration info.
-	/// None when not an appservice.
-	pub(crate) appservice_info: Option<RegistrationInfo>,
-
-	/// Parsed JSON content.
-	/// None when body is not a valid string
+	/// Parsed JSON body. None when body is not JSON.
 	pub(crate) json_body: Option<CanonicalJsonObject>,
+
+	/// Identity of the requesting entity
+	pub(crate) identity: <R::Authentication as CheckAuth>::Identity,
 }
 
-impl<T> Args<T>
+impl<R> Deref for Args<R>
 where
-	T: IncomingRequest + Send + Sync + 'static,
+	R: IncomingRequest<Authentication: CheckAuth> + Send + Sync + 'static,
 {
-	#[inline]
-	pub(crate) fn sender(&self) -> (&UserId, &DeviceId) {
-		(self.sender_user(), self.sender_device())
-	}
-
-	#[inline]
-	pub(crate) fn sender_user(&self) -> &UserId {
-		self.sender_user
-			.as_deref()
-			.expect("user must be authenticated for this handler")
-	}
-
-	#[inline]
-	pub(crate) fn sender_device(&self) -> &DeviceId {
-		self.sender_device
-			.as_deref()
-			.expect("user must be authenticated and device identified")
-	}
-
-	#[inline]
-	pub(crate) fn origin(&self) -> &ServerName {
-		self.origin
-			.as_deref()
-			.expect("server must be authenticated for this handler")
-	}
-}
-
-impl<T> Deref for Args<T>
-where
-	T: IncomingRequest + Send + Sync + 'static,
-{
-	type Target = T;
+	type Target = R;
 
 	fn deref(&self) -> &Self::Target { &self.body }
 }
@@ -145,13 +97,6 @@ where
 		let body = R::try_from_http_request(request, &path)
 			.map_err(|e| err!(Request(BadJson(debug_warn!("{e}")))))?;
 
-		Ok(Self {
-			body,
-			origin: auth.origin,
-			sender_user: auth.sender_user,
-			sender_device: auth.sender_device,
-			appservice_info: auth.appservice_info,
-			json_body,
-		})
+		Ok(Self { body, json_body, identity: auth })
 	}
 }

src/api/router/auth.rs

@@ -3,7 +3,7 @@ use std::any::{Any, TypeId};
 use conduwuit::{Err, Error, Result, err};
 use http::StatusCode;
 use ruma::{
-	OwnedDeviceId, OwnedServerName, OwnedUserId, UserId,
+	DeviceId, OwnedDeviceId, OwnedServerName, OwnedUserId, UserId,
 	api::{
 		IncomingRequest,
 		auth_scheme::{
@@ -24,20 +24,57 @@ use service::{
 
 use crate::{router::args::AuthQueryParams, service::appservice::RegistrationInfo};
 
-#[derive(Default)]
-pub(super) struct Auth {
-	pub(super) origin: Option<OwnedServerName>,
-	pub(super) sender_user: Option<OwnedUserId>,
-	pub(super) sender_device: Option<OwnedDeviceId>,
-	pub(super) appservice_info: Option<RegistrationInfo>,
+pub(crate) enum ClientIdentity {
+	User {
+		sender_user: OwnedUserId,
+		sender_device: OwnedDeviceId,
+	},
+	Appservice {
+		sender_user: OwnedUserId,
+		sender_device: Option<OwnedDeviceId>,
+		appservice_info: Box<RegistrationInfo>,
+	},
 }
 
-pub(super) trait CheckAuth: AuthScheme {
+impl ClientIdentity {
+	pub(crate) fn sender_user(&self) -> &UserId {
+		match self {
+			| Self::User { sender_user, .. } | Self::Appservice { sender_user, .. } =>
+				sender_user,
+		}
+	}
+
+	pub(crate) fn sender_device(&self) -> Option<&DeviceId> {
+		match self {
+			| Self::User { sender_device, .. } => Some(sender_device),
+			| Self::Appservice { sender_device, .. } => sender_device.as_deref(),
+		}
+	}
+
+	pub(crate) fn expect_sender_device(&self) -> Result<&DeviceId> {
+		self.sender_device().ok_or_else(|| {
+			err!(Request(Forbidden("Appservices must masquerade to use this endpoint.")))
+		})
+	}
+
+	pub(crate) fn appservice_info(&self) -> Option<&RegistrationInfo> {
+		match self {
+			| Self::User { .. } => None,
+			| Self::Appservice { appservice_info, .. } => Some(appservice_info),
+		}
+	}
+
+	pub(crate) fn is_appservice(&self) -> bool { matches!(self, Self::Appservice { .. }) }
+}
+
+pub(crate) trait CheckAuth: AuthScheme {
+	type Identity: Send;
+
 	fn authenticate<R: IncomingRequest + Any, B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		incoming_request: &hyper::Request<B>,
 		query: AuthQueryParams,
-	) -> impl Future<Output = Result<Auth>> + Send {
+	) -> impl Future<Output = Result<Self::Identity>> + Send {
 		async move {
 			let route = TypeId::of::<R>();
 
@@ -58,17 +95,19 @@ pub(super) trait CheckAuth: AuthScheme {
 		request: &hyper::Request<B>,
 		query: AuthQueryParams,
 		route: TypeId,
-	) -> impl Future<Output = Result<Auth>> + Send;
+	) -> impl Future<Output = Result<Self::Identity>> + Send;
 }
 
 impl CheckAuth for ServerSignatures {
+	type Identity = OwnedServerName;
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		output: Self::Output,
 		request: &hyper::Request<B>,
 		_query: AuthQueryParams,
 		_route: TypeId,
-	) -> Result<Auth> {
+	) -> Result<Self::Identity> {
 		let destination = services.globals.server_name();
 		if output
 			.destination
@@ -100,10 +139,7 @@ impl CheckAuth for ServerSignatures {
 					)));
 				}
 
-				Ok(Auth {
-					origin: Some(output.origin.clone()),
-					..Default::default()
-				})
+				Ok(output.origin)
 			},
 			| Err(err) =>
 				Err!(Request(Unauthorized(warn!("Failed to verify X-Matrix header: {err}")))),
@@ -112,175 +148,181 @@ impl CheckAuth for ServerSignatures {
 }
 
 impl CheckAuth for AccessToken {
+	type Identity = ClientIdentity;
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		output: Self::Output,
 		_request: &hyper::Request<B>,
 		query: AuthQueryParams,
 		route: TypeId,
-	) -> Result<Auth> {
-		let (sender_user, sender_device, appservice_info) = {
-			if let Some((sender_user, sender_device, status)) =
-				services.users.find_from_token(&output).await
-			{
-				// If the token is expired we return a soft logout
-				if matches!(status, AccessTokenStatus::Expired) {
-					return Err(Error::Request(
-						ErrorKind::UnknownToken(
-							assign!(UnknownTokenErrorData::new(), { soft_logout: true }),
-						),
-						"This token has expired".into(),
-						StatusCode::UNAUTHORIZED,
-					));
-				}
-
-				// Locked users can only use /logout and /logout/all
-				if services
-					.users
-					.is_locked(&sender_user)
-					.await
-					.is_ok_and(std::convert::identity)
-				{
-					if !(route == TypeId::of::<client::session::logout::v3::Request>()
-						|| route == TypeId::of::<client::session::logout_all::v3::Request>())
-					{
-						return Err!(Request(UserLocked("Your account is locked.")));
-					}
-				}
-
-				(Some(sender_user), Some(sender_device), None)
-			} else if let Ok(appservice_info) = services.appservice.find_from_token(&output).await
-			{
-				let Ok(sender_user) = query.user_id.clone().map_or_else(
-					|| {
-						UserId::parse_with_server_name(
-							appservice_info.registration.sender_localpart.as_str(),
-							services.globals.server_name(),
-						)
-					},
-					UserId::parse,
-				) else {
-					return Err!(Request(InvalidUsername("Username is invalid.")));
-				};
-
-				if !appservice_info.is_user_match(&sender_user) {
-					return Err!(Request(Exclusive("User is not in namespace.")));
-				}
-
-				// MSC3202/MSC4190: Handle device_id masquerading for appservices.
-				// The device_id can be provided via `device_id` or
-				// `org.matrix.msc3202.device_id` query parameter.
-				let sender_device =
-					if let Some(device_id) = query.device_id.as_deref().map(Into::into) {
-						// Verify the device exists for this user
-						if services
-							.users
-							.get_device_metadata(&sender_user, device_id)
-							.await
-							.is_err()
-						{
-							return Err!(Request(Forbidden(
-								"Device does not exist for user or appservice cannot masquerade \
-								 as this device."
-							)));
-						}
-
-						Some(device_id.to_owned())
-					} else {
-						None
-					};
-
-				(Some(sender_user), sender_device, Some(appservice_info))
-			} else {
+	) -> Result<Self::Identity> {
+		if let Some((sender_user, sender_device, status)) =
+			services.users.find_from_token(&output).await
+		{
+			// If the token is expired we return a soft logout
+			if matches!(status, AccessTokenStatus::Expired) {
 				return Err(Error::Request(
-					ErrorKind::UnknownToken(UnknownTokenErrorData::new()),
-					"Invalid token".into(),
+					ErrorKind::UnknownToken(
+						assign!(UnknownTokenErrorData::new(), { soft_logout: true }),
+					),
+					"This token has expired".into(),
 					StatusCode::UNAUTHORIZED,
 				));
 			}
-		};
 
-		Ok(Auth {
-			sender_user,
-			sender_device,
-			appservice_info,
-			..Default::default()
-		})
+			// Locked users can only use /logout and /logout/all
+			if services
+				.users
+				.is_locked(&sender_user)
+				.await
+				.is_ok_and(std::convert::identity)
+			{
+				if !(route == TypeId::of::<client::session::logout::v3::Request>()
+					|| route == TypeId::of::<client::session::logout_all::v3::Request>())
+				{
+					return Err!(Request(UserLocked("Your account is locked.")));
+				}
+			}
+
+			Ok(ClientIdentity::User { sender_user, sender_device })
+		} else if let Ok(appservice_info) = services.appservice.find_from_token(&output).await {
+			let Ok(sender_user) = query.user_id.clone().map_or_else(
+				|| {
+					UserId::parse_with_server_name(
+						appservice_info.registration.sender_localpart.as_str(),
+						services.globals.server_name(),
+					)
+				},
+				UserId::parse,
+			) else {
+				return Err!(Request(InvalidUsername("Username is invalid.")));
+			};
+
+			if !appservice_info.is_user_match(&sender_user) {
+				return Err!(Request(Exclusive("User is not in namespace.")));
+			}
+
+			// MSC3202/MSC4190: Handle device_id masquerading for appservices.
+			// The device_id can be provided via `device_id` or
+			// `org.matrix.msc3202.device_id` query parameter.
+			let sender_device =
+				if let Some(device_id) = query.device_id.as_deref().map(Into::into) {
+					// Verify the device exists for this user
+					if services
+						.users
+						.get_device_metadata(&sender_user, device_id)
+						.await
+						.is_err()
+					{
+						return Err!(Request(Forbidden(
+							"Device does not exist for user or appservice cannot masquerade as \
+							 this device."
+						)));
+					}
+
+					Some(device_id.to_owned())
+				} else {
+					None
+				};
+
+			Ok(ClientIdentity::Appservice {
+				sender_user,
+				sender_device,
+				appservice_info: Box::new(appservice_info),
+			})
+		} else {
+			Err(Error::Request(
+				ErrorKind::UnknownToken(UnknownTokenErrorData::new()),
+				"Invalid token".into(),
+				StatusCode::UNAUTHORIZED,
+			))
+		}
 	}
 }
 
 impl CheckAuth for AccessTokenOptional {
+	type Identity = Option<ClientIdentity>;
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		output: Self::Output,
 		request: &hyper::Request<B>,
 		query: AuthQueryParams,
 		route: TypeId,
-	) -> Result<Auth> {
+	) -> Result<Self::Identity> {
 		match output {
 			| Some(token) =>
-				<AccessToken as CheckAuth>::verify(services, token, request, query, route).await,
-			| None => Ok(Auth::default()),
+				<AccessToken as CheckAuth>::verify(services, token, request, query, route)
+					.await
+					.map(Some),
+			| None => Ok(None),
 		}
 	}
 }
 
 impl CheckAuth for AppserviceToken {
+	type Identity = RegistrationInfo;
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		output: Self::Output,
 		_request: &hyper::Request<B>,
 		_query: AuthQueryParams,
 		_route: TypeId,
-	) -> Result<Auth> {
+	) -> Result<Self::Identity> {
 		let Ok(appservice_info) = services.appservice.find_from_token(&output).await else {
 			return Err!(Request(Unauthorized("Invalid appservice token.")));
 		};
 
-		Ok(Auth {
-			appservice_info: Some(appservice_info),
-			..Default::default()
-		})
+		Ok(appservice_info)
 	}
 }
 
 impl CheckAuth for AppserviceTokenOptional {
+	type Identity = Option<RegistrationInfo>;
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		output: Self::Output,
 		request: &hyper::Request<B>,
 		query: AuthQueryParams,
 		route: TypeId,
-	) -> Result<Auth> {
+	) -> Result<Self::Identity> {
 		match output {
 			| Some(token) =>
 				<AppserviceToken as CheckAuth>::verify(services, token, request, query, route)
-					.await,
-			| None => Ok(Auth::default()),
+					.await
+					.map(Some),
+			| None => Ok(None),
 		}
 	}
 }
 
 impl CheckAuth for NoAuthentication {
+	type Identity = ();
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		_services: &Services,
 		_output: Self::Output,
 		_request: &hyper::Request<B>,
 		_query: AuthQueryParams,
 		_route: TypeId,
-	) -> Result<Auth> {
-		Ok(Auth::default())
+	) -> Result<Self::Identity> {
+		Ok(())
 	}
 }
 
 impl CheckAuth for NoAccessToken {
+	type Identity = Option<ClientIdentity>;
+
 	async fn verify<B: AsRef<[u8]> + Sync>(
 		services: &Services,
 		_output: Self::Output,
 		request: &hyper::Request<B>,
 		query: AuthQueryParams,
 		route: TypeId,
-	) -> Result<Auth> {
+	) -> Result<Self::Identity> {
 		// We handle these the same as AccessTokenOptional
 		let token = AccessTokenOptional::extract_authentication(request).map_err(|err| {
 			err!(Request(Unauthorized(warn!("Failed to extract authorization: {}", err))))

src/api/server/backfill.rs

@@ -28,7 +28,7 @@ pub(crate) async fn get_backfill_route(
 ) -> Result<get_backfill::v1::Response> {
 	AccessCheck {
 		services: &services,
-		origin: body.origin(),
+		origin: &body.identity,
 		room_id: &body.room_id,
 		event_id: None,
 	}
@@ -41,7 +41,7 @@ pub(crate) async fn get_backfill_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve backfill for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
@@ -76,7 +76,7 @@ pub(crate) async fn get_backfill_route(
 			Ok(services
 				.rooms
 				.state_accessor
-				.server_can_see_event(body.origin(), &pdu.room_id_or_hash(), &pdu.event_id)
+				.server_can_see_event(&body.identity, &pdu.room_id_or_hash(), &pdu.event_id)
 				.await
 				.then_some(pdu))
 		})

src/api/server/event.rs

@@ -40,7 +40,7 @@ pub(crate) async fn get_event_route(
 
 	AccessCheck {
 		services: &services,
-		origin: body.origin(),
+		origin: &body.identity,
 		room_id,
 		event_id: Some(&body.event_id),
 	}
@@ -54,7 +54,7 @@ pub(crate) async fn get_event_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve state for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));

src/api/server/event_auth.rs

@@ -19,7 +19,7 @@ pub(crate) async fn get_event_authorization_route(
 ) -> Result<get_event_authorization::v1::Response> {
 	AccessCheck {
 		services: &services,
-		origin: body.origin(),
+		origin: &body.identity,
 		room_id: &body.room_id,
 		event_id: None,
 	}
@@ -42,7 +42,7 @@ pub(crate) async fn get_event_authorization_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve state for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));

src/api/server/get_missing_events.rs

@@ -22,7 +22,7 @@ pub(crate) async fn get_missing_events_route(
 ) -> Result<get_missing_events::v1::Response> {
 	AccessCheck {
 		services: &services,
-		origin: body.origin(),
+		origin: &body.identity,
 		room_id: &body.room_id,
 		event_id: None,
 	}
@@ -36,7 +36,7 @@ pub(crate) async fn get_missing_events_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve state for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
@@ -91,10 +91,10 @@ pub(crate) async fn get_missing_events_route(
 		if !services
 			.rooms
 			.state_accessor
-			.server_can_see_event(body.origin(), &body.room_id, pdu.event_id())
+			.server_can_see_event(&body.identity, &body.room_id, pdu.event_id())
 			.await
 		{
-			debug!(%next_event_id, origin = %body.origin(), "redacting event origin cannot see");
+			debug!(%next_event_id, origin = %body.identity, "redacting event origin cannot see");
 			pdu.redact(&room_version, json!({}))?;
 		}
 

src/api/server/hierarchy.rs

@@ -20,7 +20,7 @@ pub(crate) async fn get_hierarchy_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve state for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
@@ -29,7 +29,7 @@ pub(crate) async fn get_hierarchy_route(
 	let response = services
 		.rooms
 		.summary
-		.get_local_room_summary_for_server(body.origin(), &body.room_id, body.suggested_only)
+		.get_local_room_summary_for_server(&body.identity, &body.room_id, body.suggested_only)
 		.await;
 
 	if let Accessibility::Accessible(response) = response {

src/api/server/invite.rs

@@ -32,7 +32,7 @@ pub(crate) async fn create_invite_route(
 	services
 		.rooms
 		.event_handler
-		.acl_check(body.origin(), &body.room_id)
+		.acl_check(&body.identity, &body.room_id)
 		.await?;
 
 	if !services.server.supported_room_version(&body.room_version) {
@@ -54,12 +54,11 @@ pub(crate) async fn create_invite_route(
 
 	if services
 		.moderation
-		.is_remote_server_forbidden(body.origin())
+		.is_remote_server_forbidden(&body.identity)
 	{
 		warn!(
 			"Received federated/remote invite from banned server {} for room ID {}. Rejecting.",
-			body.origin(),
-			body.room_id
+			body.identity, body.room_id
 		);
 
 		return Err!(Request(Forbidden("Server is banned on this homeserver.")));
@@ -105,7 +104,7 @@ pub(crate) async fn create_invite_route(
 		.and_then(Result::ok)
 		.ok_or_else(|| err!(Request(InvalidParam("Invalid sender property"))))?;
 
-	if sender_user.server_name() != body.origin() {
+	if sender_user.server_name() != body.identity {
 		return Err!(Request(Forbidden("Sender's server does not match the origin server.",)));
 	}
 

src/api/server/make_join.rs

@@ -30,7 +30,7 @@ use crate::Ruma;
 /// # `GET /_matrix/federation/v1/make_join/{roomId}/{userId}`
 ///
 /// Creates a join template.
-#[tracing::instrument(skip_all, fields(room_id = %body.room_id, user_id = %body.user_id, origin = %body.origin()), level = "info")]
+#[tracing::instrument(skip_all, fields(room_id = %body.room_id, user_id = %body.user_id, origin = %body.identity), level = "info")]
 pub(crate) async fn create_join_event_template_route(
 	State(services): State<crate::State>,
 	body: Ruma<prepare_join_event::v1::Request>,
@@ -45,14 +45,14 @@ pub(crate) async fn create_join_event_template_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			room_id = %body.room_id,
 			"Refusing to serve make_join for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
 	}
 
-	if body.user_id.server_name() != body.origin() {
+	if body.user_id.server_name() != body.identity {
 		return Err!(Request(BadJson("Not allowed to join on behalf of another server/user.")));
 	}
 
@@ -60,19 +60,17 @@ pub(crate) async fn create_join_event_template_route(
 	services
 		.rooms
 		.event_handler
-		.acl_check(body.origin(), &body.room_id)
+		.acl_check(&body.identity, &body.room_id)
 		.await?;
 
 	if services
 		.moderation
-		.is_remote_server_forbidden(body.origin())
+		.is_remote_server_forbidden(&body.identity)
 	{
 		warn!(
 			"Server {} for remote user {} tried joining room ID {} which has a server name that \
 			 is globally forbidden. Rejecting.",
-			body.origin(),
-			&body.user_id,
-			&body.room_id,
+			body.identity, &body.user_id, &body.room_id,
 		);
 		return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 	}

src/api/server/make_knock.rs

@@ -28,14 +28,14 @@ pub(crate) async fn create_knock_event_template_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			room_id = %body.room_id,
 			"Refusing to serve make_knock for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
 	}
 
-	if body.user_id.server_name() != body.origin() {
+	if body.user_id.server_name() != body.identity {
 		return Err!(Request(BadJson("Not allowed to knock on behalf of another server/user.")));
 	}
 
@@ -43,19 +43,17 @@ pub(crate) async fn create_knock_event_template_route(
 	services
 		.rooms
 		.event_handler
-		.acl_check(body.origin(), &body.room_id)
+		.acl_check(&body.identity, &body.room_id)
 		.await?;
 
 	if services
 		.moderation
-		.is_remote_server_forbidden(body.origin())
+		.is_remote_server_forbidden(&body.identity)
 	{
 		warn!(
 			"Server {} for remote user {} tried knocking room ID {} which has a server name \
 			 that is globally forbidden. Rejecting.",
-			body.origin(),
-			&body.user_id,
-			&body.room_id,
+			body.identity, &body.user_id, &body.room_id,
 		);
 		return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 	}

src/api/server/make_leave.rs

@@ -26,13 +26,13 @@ pub(crate) async fn create_leave_event_template_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve make_leave for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
 	}
 
-	if body.user_id.server_name() != body.origin() {
+	if body.user_id.server_name() != body.identity {
 		return Err!(Request(Forbidden(
 			"Not allowed to leave on behalf of another server/user."
 		)));
@@ -42,7 +42,7 @@ pub(crate) async fn create_leave_event_template_route(
 	services
 		.rooms
 		.event_handler
-		.acl_check(body.origin(), &body.room_id)
+		.acl_check(&body.identity, &body.room_id)
 		.await?;
 
 	let room_version = services.rooms.state.get_room_version(&body.room_id).await?;

src/api/server/send.rs

@@ -62,7 +62,7 @@ pub(crate) async fn send_transaction_message_route(
 	ClientIp(client): ClientIp,
 	body: Ruma<send_transaction_message::v1::Request>,
 ) -> Result<send_transaction_message::v1::Response> {
-	if body.origin() != body.body.origin {
+	if body.identity != body.body.origin {
 		return Err!(Request(Forbidden(
 			"Not allowed to send transactions on behalf of other servers"
 		)));
@@ -80,7 +80,7 @@ pub(crate) async fn send_transaction_message_route(
 		)));
 	}
 
-	let txn_key = (body.origin().to_owned(), body.transaction_id.clone());
+	let txn_key = (body.identity.clone(), body.transaction_id.clone());
 
 	// Atomically check cache, join active, or start new transaction
 	match services
@@ -136,7 +136,7 @@ async fn wait_for_result(
 	skip_all,
 	fields(
 		id = ?body.transaction_id.as_str(),
-		origin = ?body.origin()
+		origin = ?body.identity
 	)
 )]
 async fn process_inbound_transaction(
@@ -164,7 +164,7 @@ async fn process_inbound_transaction(
 		.stream();
 
 	debug!(pdus = body.pdus.len(), edus = body.edus.len(), "Processing transaction",);
-	let results = match handle(&services, &client, body.origin(), pdus, edus).await {
+	let results = match handle(&services, &client, &body.identity, pdus, edus).await {
 		| Ok(results) => results,
 		| Err(err) => {
 			fail_federation_txn(services, &txn_key, &sender, err);

src/api/server/send_join.rs

@@ -304,7 +304,7 @@ pub(crate) async fn create_join_event_v2_route(
 ) -> Result<create_join_event::v2::Response> {
 	if services
 		.moderation
-		.is_remote_server_forbidden(body.origin())
+		.is_remote_server_forbidden(&body.identity)
 	{
 		return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 	}
@@ -314,8 +314,7 @@ pub(crate) async fn create_join_event_v2_route(
 			warn!(
 				"Server {} tried joining room ID {} through us which has a server name that is \
 				 globally forbidden. Rejecting.",
-				body.origin(),
-				&body.room_id,
+				body.identity, &body.room_id,
 			);
 			return Err!(Request(Forbidden(warn!(
 				"Room ID server name {server} is banned on this homeserver."
@@ -325,12 +324,12 @@ pub(crate) async fn create_join_event_v2_route(
 
 	let now = Instant::now();
 	let room_state =
-		create_join_event(&services, body.origin(), &body.room_id, &body.pdu, body.omit_members)
+		create_join_event(&services, &body.identity, &body.room_id, &body.pdu, body.omit_members)
 			.boxed()
 			.await?;
 	info!(
 		"Finished sending a join for {} in {} in {:?}",
-		body.origin(),
+		body.identity,
 		&body.room_id,
 		now.elapsed()
 	);

src/api/server/send_knock.rs

@@ -26,13 +26,12 @@ pub(crate) async fn create_knock_event_v1_route(
 ) -> Result<create_knock_event::v1::Response> {
 	if services
 		.moderation
-		.is_remote_server_forbidden(body.origin())
+		.is_remote_server_forbidden(&body.identity)
 	{
 		warn!(
 			"Server {} tried knocking room ID {} who has a server name that is globally \
 			 forbidden. Rejecting.",
-			body.origin(),
-			&body.room_id,
+			body.identity, &body.room_id,
 		);
 		return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 	}
@@ -42,8 +41,7 @@ pub(crate) async fn create_knock_event_v1_route(
 			warn!(
 				"Server {} tried knocking room ID {} which has a server name that is globally \
 				 forbidden. Rejecting.",
-				body.origin(),
-				&body.room_id,
+				body.identity, &body.room_id,
 			);
 			return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 		}
@@ -60,7 +58,7 @@ pub(crate) async fn create_knock_event_v1_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve send_knock for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));
@@ -70,7 +68,7 @@ pub(crate) async fn create_knock_event_v1_route(
 	services
 		.rooms
 		.event_handler
-		.acl_check(body.origin(), &body.room_id)
+		.acl_check(&body.identity, &body.room_id)
 		.await?;
 
 	let room_version = services.rooms.state.get_room_version(&body.room_id).await?;
@@ -133,7 +131,7 @@ pub(crate) async fn create_knock_event_v1_route(
 		.await?;
 
 	// check if origin server is trying to send for another server
-	if sender.server_name() != body.origin() {
+	if sender.server_name() != body.identity {
 		return Err!(Request(BadJson("Not allowed to knock on behalf of another server/user.")));
 	}
 

src/api/server/send_leave.rs

@@ -21,7 +21,7 @@ pub(crate) async fn create_leave_event_v2_route(
 	State(services): State<crate::State>,
 	body: Ruma<create_leave_event::v2::Request>,
 ) -> Result<create_leave_event::v2::Response> {
-	create_leave_event(&services, body.origin(), &body.room_id, &body.pdu).await?;
+	create_leave_event(&services, &body.identity, &body.room_id, &body.pdu).await?;
 
 	Ok(create_leave_event::v2::Response::new())
 }

src/api/server/state.rs

@@ -17,7 +17,7 @@ pub(crate) async fn get_room_state_route(
 ) -> Result<get_room_state::v1::Response> {
 	AccessCheck {
 		services: &services,
-		origin: body.origin(),
+		origin: &body.identity,
 		room_id: &body.room_id,
 		event_id: None,
 	}
@@ -40,7 +40,7 @@ pub(crate) async fn get_room_state_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve state for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));

src/api/server/state_ids.rs

@@ -18,7 +18,7 @@ pub(crate) async fn get_room_state_ids_route(
 ) -> Result<get_room_state_ids::v1::Response> {
 	AccessCheck {
 		services: &services,
-		origin: body.origin(),
+		origin: &body.identity,
 		room_id: &body.room_id,
 		event_id: None,
 	}
@@ -41,7 +41,7 @@ pub(crate) async fn get_room_state_ids_route(
 		.await
 	{
 		info!(
-			origin = body.origin().as_str(),
+			origin = body.identity.as_str(),
 			"Refusing to serve state for room we aren't participating in"
 		);
 		return Err!(Request(NotFound("This server is not participating in that room.")));

src/api/server/user.rs

@@ -60,13 +60,13 @@ pub(crate) async fn get_devices_route(
 
 	let master_key = services
 		.users
-		.get_master_key(None, &body.user_id, &|u| u.server_name() == body.origin())
+		.get_master_key(None, &body.user_id, &|u| u.server_name() == body.identity)
 		.await
 		.ok();
 
 	let self_signing_key = services
 		.users
-		.get_self_signing_key(None, &body.user_id, &|u| u.server_name() == body.origin())
+		.get_self_signing_key(None, &body.user_id, &|u| u.server_name() == body.identity)
 		.await
 		.ok();
 
@@ -94,7 +94,7 @@ pub(crate) async fn get_keys_route(
 		&services,
 		None,
 		&body.device_keys,
-		|u| Some(u.server_name()) == body.origin.as_deref(),
+		|u| u.server_name() == body.identity,
 		services.globals.allow_device_name_federation(),
 		Duration::from_secs(0),
 	)

src/core/config/mod.rs

@@ -2077,10 +2077,12 @@ pub struct Config {
 	pub stream_amplification: usize,
 
 	/// Number of sender task workers; determines sender parallelism. Default is
-	/// core count. Override by setting a different value.
+	/// '0' which means the value is determined internally, likely matching the
+	/// number of tokio worker-threads or number of cores, etc. Override by
+	/// setting a non-zero value.
 	///
-	/// default: core count
-	#[serde(default = "default_sender_workers")]
+	/// default: 0
+	#[serde(default)]
 	pub sender_workers: usize,
 
 	/// Enables listener sockets; can be set to false to disable listening. This
@@ -2520,47 +2522,45 @@ fn default_database_backups_to_keep() -> i16 { 1 }
 
 fn default_db_write_buffer_capacity_mb() -> f64 { 48.0 + parallelism_scaled_f64(4.0) }
 
-fn default_db_cache_capacity_mb() -> f64 { 512.0 + parallelism_scaled_f64(512.0) }
+fn default_db_cache_capacity_mb() -> f64 { 128.0 + parallelism_scaled_f64(64.0) }
 
-fn default_pdu_cache_capacity() -> u32 { parallelism_scaled_u32(50_000).saturating_add(100_000) }
+fn default_pdu_cache_capacity() -> u32 { parallelism_scaled_u32(10_000).saturating_add(100_000) }
 
 fn default_cache_capacity_modifier() -> f64 { 1.0 }
 
 fn default_auth_chain_cache_capacity() -> u32 {
-	parallelism_scaled_u32(50_000).saturating_add(100_000)
+	parallelism_scaled_u32(10_000).saturating_add(100_000)
 }
 
 fn default_shorteventid_cache_capacity() -> u32 {
-	parallelism_scaled_u32(100_000).saturating_add(100_000)
+	parallelism_scaled_u32(50_000).saturating_add(100_000)
 }
 
 fn default_eventidshort_cache_capacity() -> u32 {
-	parallelism_scaled_u32(50_000).saturating_add(100_000)
+	parallelism_scaled_u32(25_000).saturating_add(100_000)
 }
 
 fn default_eventid_pdu_cache_capacity() -> u32 {
-	parallelism_scaled_u32(50_000).saturating_add(100_000)
+	parallelism_scaled_u32(25_000).saturating_add(100_000)
 }
 
 fn default_shortstatekey_cache_capacity() -> u32 {
-	parallelism_scaled_u32(100_000).saturating_add(100_000)
+	parallelism_scaled_u32(10_000).saturating_add(100_000)
 }
 
 fn default_statekeyshort_cache_capacity() -> u32 {
-	parallelism_scaled_u32(50_000).saturating_add(100_000)
+	parallelism_scaled_u32(10_000).saturating_add(100_000)
 }
 
 fn default_servernameevent_data_cache_capacity() -> u32 {
-	parallelism_scaled_u32(100_000).saturating_add(100_000)
+	parallelism_scaled_u32(100_000).saturating_add(500_000)
 }
 
-fn default_stateinfo_cache_capacity() -> u32 { parallelism_scaled_u32(500).clamp(100, 12000) }
+fn default_stateinfo_cache_capacity() -> u32 { parallelism_scaled_u32(100) }
 
-fn default_roomid_spacehierarchy_cache_capacity() -> u32 {
-	parallelism_scaled_u32(500).clamp(100, 12000)
-}
+fn default_roomid_spacehierarchy_cache_capacity() -> u32 { parallelism_scaled_u32(1000) }
 
-fn default_dns_cache_entries() -> u32 { 327_680 }
+fn default_dns_cache_entries() -> u32 { 32768 }
 
 fn default_dns_min_ttl() -> u64 { 60 * 180 }
 
@@ -2768,26 +2768,15 @@ fn default_admin_log_capture() -> String {
 
 fn default_admin_room_tag() -> String { "m.server_notice".to_owned() }
 
-#[must_use]
 #[allow(clippy::as_conversions, clippy::cast_precision_loss)]
-pub fn parallelism_scaled_f64(val: f64) -> f64 { val * (sys::available_parallelism() as f64) }
+fn parallelism_scaled_f64(val: f64) -> f64 { val * (sys::available_parallelism() as f64) }
 
-#[must_use]
-#[allow(clippy::as_conversions, clippy::cast_possible_truncation)]
-pub fn parallelism_scaled_u32(val: u32) -> u32 {
-	val.saturating_mul(sys::available_parallelism() as u32)
+fn parallelism_scaled_u32(val: u32) -> u32 {
+	let val = val.try_into().expect("failed to cast u32 to usize");
+	parallelism_scaled(val).try_into().unwrap_or(u32::MAX)
 }
 
-#[must_use]
-#[allow(clippy::as_conversions, clippy::cast_possible_truncation, clippy::cast_possible_wrap)]
-pub fn parallelism_scaled_i32(val: i32) -> i32 {
-	val.saturating_mul(sys::available_parallelism() as i32)
-}
-
-#[must_use]
-pub fn parallelism_scaled(val: usize) -> usize {
-	val.saturating_mul(sys::available_parallelism())
-}
+fn parallelism_scaled(val: usize) -> usize { val.saturating_mul(sys::available_parallelism()) }
 
 fn default_trusted_server_batch_size() -> usize { 256 }
 
@@ -2807,8 +2796,6 @@ fn default_stream_width_scale() -> f32 { 1.0 }
 
 fn default_stream_amplification() -> usize { 1024 }
 
-fn default_sender_workers() -> usize { parallelism_scaled(1) }
-
 fn default_client_receive_timeout() -> u64 { 75 }
 
 fn default_client_request_timeout() -> u64 { 180 }

src/core/utils/hash/sha256.rs

@@ -5,7 +5,6 @@ pub type DigestOut = [u8; 256 / 8];
 /// Sha256 hash (input gather joined by 0xFF bytes)
 #[must_use]
 #[tracing::instrument(skip(inputs), level = "trace")]
-#[allow(clippy::unnecessary_fallible_conversions)]
 pub fn delimited<'a, T, I>(mut inputs: I) -> DigestOut
 where
 	I: Iterator<Item = T> + 'a,
@@ -26,7 +25,6 @@ where
 /// Sha256 hash (input gather)
 #[must_use]
 #[tracing::instrument(skip(inputs), level = "trace")]
-#[allow(clippy::unnecessary_fallible_conversions)]
 pub fn concat<'a, T, I>(inputs: I) -> DigestOut
 where
 	I: Iterator<Item = T> + 'a,
@@ -45,7 +43,6 @@ where
 #[inline]
 #[must_use]
 #[tracing::instrument(skip(input), level = "trace")]
-#[allow(clippy::unnecessary_fallible_conversions)]
 pub fn hash<T>(input: T) -> DigestOut
 where
 	T: AsRef<[u8]>,

src/database/engine/cf_opts.rs

@@ -29,7 +29,7 @@ fn descriptor_cf_options(
 	set_table_options(&mut opts, &desc, cache)?;
 
 	opts.set_min_write_buffer_number(1);
-	opts.set_max_write_buffer_number(3);
+	opts.set_max_write_buffer_number(2);
 	opts.set_write_buffer_size(desc.write_size);
 
 	opts.set_target_file_size_base(desc.file_size);

src/database/maps.rs

@@ -201,7 +201,12 @@ pub(super) static MAPS: &[Descriptor] = &[
 	},
 	Descriptor {
 		name: "roomsynctoken_shortstatehash",
-		..descriptor::DROPPED
+		file_shape: 3,
+		val_size_hint: Some(8),
+		block_size: 512,
+		compression_level: 3,
+		bottommost_level: Some(6),
+		..descriptor::SEQUENTIAL
 	},
 	Descriptor {
 		name: "roomuserdataid_accountdata",

src/router/request.rs

@@ -8,7 +8,7 @@ use axum::{
 	extract::State,
 	response::{IntoResponse, Response},
 };
-use conduwuit::{Result, debug_warn, err, error, info, trace};
+use conduwuit::{Result, debug, debug_error, debug_warn, err, error, trace};
 use conduwuit_service::Services;
 use futures::FutureExt;
 use http::{Method, StatusCode, Uri};
@@ -102,11 +102,11 @@ fn handle_result(method: &Method, uri: &Uri, result: Response) -> Result<Respons
 	let reason = status.canonical_reason().unwrap_or("Unknown Reason");
 
 	if status.is_server_error() {
-		info!(%method, %uri, "{code} {reason}");
+		error!(%method, %uri, "{code} {reason}");
 	} else if status.is_client_error() {
-		info!(%method, %uri, "{code} {reason}");
+		debug_error!(%method, %uri, "{code} {reason}");
 	} else if status.is_redirection() {
-		trace!(%method, %uri, "{code} {reason}");
+		debug!(%method, %uri, "{code} {reason}");
 	} else {
 		trace!(%method, %uri, "{code} {reason}");
 	}

src/service/presence/mod.rs

@@ -100,7 +100,7 @@ impl Service {
 	/// Pings the presence of the given user in the given room, setting the
 	/// specified state.
 	pub async fn ping_presence(&self, user_id: &UserId, new_state: &PresenceState) -> Result<()> {
-		const REFRESH_TIMEOUT: u64 = 60 * 1000 * 4;
+		const REFRESH_TIMEOUT: u64 = 60 * 1000;
 
 		let last_presence = self.db.get_presence(user_id).await;
 		let state_changed = match last_presence {

src/service/rooms/alias/mod.rs

@@ -294,7 +294,7 @@ impl Service {
 	pub async fn appservice_checks(
 		&self,
 		room_alias: &RoomAliasId,
-		appservice_info: &Option<RegistrationInfo>,
+		appservice_info: Option<&RegistrationInfo>,
 	) -> Result<()> {
 		if !self
 			.services

src/service/rooms/event_handler/fetch_and_handle_outliers.rs

@@ -80,7 +80,7 @@ where
 			{
 				// Exponential backoff
 				const MIN_DURATION: u64 = 60 * 2;
-				const MAX_DURATION: u64 = 60 * 60;
+				const MAX_DURATION: u64 = 60 * 60 * 8;
 				if continue_exponential_backoff_secs(
 					MIN_DURATION,
 					MAX_DURATION,

src/service/rooms/event_handler/handle_prev_pdu.rs

@@ -46,7 +46,7 @@ where
 	{
 		// Exponential backoff
 		const MIN_DURATION: u64 = 5 * 60;
-		const MAX_DURATION: u64 = 60 * 60;
+		const MAX_DURATION: u64 = 60 * 60 * 24;
 		if continue_exponential_backoff_secs(MIN_DURATION, MAX_DURATION, time.elapsed(), *tries) {
 			debug!(
 				?tries,

src/service/rooms/user/mod.rs

@@ -1,10 +1,10 @@
 use std::sync::Arc;
 
 use conduwuit::{Result, implement};
-use database::{Deserialized, Map};
+use database::{Database, Deserialized, Map};
 use ruma::{RoomId, UserId};
 
-use crate::{Dep, globals};
+use crate::{Dep, globals, rooms, rooms::short::ShortStateHash};
 
 pub struct Service {
 	db: Data,
@@ -12,25 +12,32 @@ pub struct Service {
 }
 
 struct Data {
+	db: Arc<Database>,
 	userroomid_notificationcount: Arc<Map>,
 	userroomid_highlightcount: Arc<Map>,
 	roomuserid_lastnotificationread: Arc<Map>,
+	roomsynctoken_shortstatehash: Arc<Map>,
 }
 
 struct Services {
 	globals: Dep<globals::Service>,
+	short: Dep<rooms::short::Service>,
 }
 
 impl crate::Service for Service {
 	fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
 		Ok(Arc::new(Self {
 			db: Data {
+				db: args.db.clone(),
 				userroomid_notificationcount: args.db["userroomid_notificationcount"].clone(),
 				userroomid_highlightcount: args.db["userroomid_highlightcount"].clone(),
 				roomuserid_lastnotificationread: args.db["userroomid_highlightcount"].clone(),
+				roomsynctoken_shortstatehash: args.db["roomsynctoken_shortstatehash"].clone(),
 			},
+
 			services: Services {
 				globals: args.depend::<globals::Service>("globals"),
+				short: args.depend::<rooms::short::Service>("rooms::short"),
 			},
 		}))
 	}
@@ -83,3 +90,40 @@ pub async fn last_notification_read(&self, user_id: &UserId, room_id: &RoomId) -
 		.deserialized()
 		.unwrap_or(0)
 }
+
+#[implement(Service)]
+pub async fn associate_token_shortstatehash(
+	&self,
+	room_id: &RoomId,
+	token: u64,
+	shortstatehash: ShortStateHash,
+) {
+	let shortroomid = self
+		.services
+		.short
+		.get_shortroomid(room_id)
+		.await
+		.expect("room exists");
+
+	let _cork = self.db.db.cork();
+	let key: &[u64] = &[shortroomid, token];
+	self.db
+		.roomsynctoken_shortstatehash
+		.put(key, shortstatehash);
+}
+
+#[implement(Service)]
+pub async fn get_token_shortstatehash(
+	&self,
+	room_id: &RoomId,
+	token: u64,
+) -> Result<ShortStateHash> {
+	let shortroomid = self.services.short.get_shortroomid(room_id).await?;
+
+	let key: &[u64] = &[shortroomid, token];
+	self.db
+		.roomsynctoken_shortstatehash
+		.qry(key)
+		.await
+		.deserialized()
+}

src/service/uiaa/mod.rs

@@ -92,20 +92,20 @@ impl UiaaSessionMetadata {
 /// Information about the user which is initiating this UIAA session.
 pub struct UiaaInitiator<'a> {
 	user_id: &'a UserId,
-	device_id: &'a DeviceId,
+	device_id: Option<&'a DeviceId>,
 	oauth_ticket: Option<OAuthTicket>,
 }
 
 impl<'a> UiaaInitiator<'a> {
 	#[must_use]
-	pub fn new(user_id: &'a UserId, device_id: &'a DeviceId) -> Self {
+	pub fn new(user_id: &'a UserId, device_id: Option<&'a DeviceId>) -> Self {
 		Self { user_id, device_id, oauth_ticket: None }
 	}
 
 	#[must_use]
 	pub fn with_oauth_ticket(
 		user_id: &'a UserId,
-		device_id: &'a DeviceId,
+		device_id: Option<&'a DeviceId>,
 		oauth_ticket: OAuthTicket,
 	) -> Self {
 		Self {
@@ -220,7 +220,7 @@ impl Service {
 		&self,
 		auth: &Option<AuthData>,
 		user_id: &UserId,
-		device_id: &DeviceId,
+		device_id: Option<&DeviceId>,
 		oauth_ticket: Option<OAuthTicket>,
 	) -> Result<Identity> {
 		self.authenticate(
@@ -252,12 +252,16 @@ impl Service {
 		let mut info = assign!(UiaaInfo::new(flows), { params: Some(params), session: Some(session_id.clone()) });
 
 		let session_metadata = if let Some(initiator) = initiator {
-			let is_oauth = self
-				.services
-				.oauth
-				.get_session_info_for_device(initiator.user_id, initiator.device_id)
-				.await
-				.is_some();
+			let is_oauth = if let Some(device_id) = initiator.device_id {
+				self.services
+					.oauth
+					.get_session_info_for_device(initiator.user_id, device_id)
+					.await
+					.is_some()
+			} else {
+				// Appservices never have oauth sessions
+				false
+			};
 
 			if is_oauth {
 				if let Some(oauth_ticket) = initiator.oauth_ticket {