changelog.d/+space-permission-cascading.feature.md

@@ -0,0 +1 @@
+Add Space permission cascading: power levels cascade from Spaces to child rooms, role-based room access with custom roles, continuous enforcement (auto-join/kick), and admin commands for role management. Server-wide default controlled by `space_permission_cascading` config flag (off by default), with per-Space overrides via `!admin space roles enable/disable <space>`.

conduwuit-example.toml

@@ -470,6 +470,18 @@
 #
 #suspend_on_register = false
 
+# Server-wide default for space permission cascading (power levels and
+# role-based access). Individual Spaces can override this via the
+# `com.continuwuity.space.cascading` state event or the admin command
+# `!admin space roles enable/disable <space>`.
+#
+#space_permission_cascading = false
+
+# Maximum number of spaces to cache role data for. When exceeded the
+# cache is cleared and repopulated on demand.
+#
+#space_roles_cache_flush_threshold = 1000
+
 # Enabling this setting opens registration to anyone without restrictions.
 # This makes your server vulnerable to abuse
 #

docs/plans/2026-03-17-space-permission-cascading-design.md

@@ -0,0 +1,226 @@
+# Space Permission Cascading — Design Document
+
+**Date:** 2026-03-17
+**Status:** Approved
+
+## Overview
+
+Server-side feature that allows user rights in a Space to cascade down to its
+direct child rooms. Includes power level cascading and role-based room access
+control. Enabled via a server-wide configuration flag, disabled by default.
+
+## Requirements
+
+1. Power levels defined in a Space cascade to all direct child rooms (Space
+   always wins over per-room overrides).
+2. Admins can define custom roles in a Space and assign them to users.
+3. Child rooms can require one or more roles for access.
+4. Enforcement is continuous — role revocation auto-kicks users from rooms they
+   no longer qualify for.
+5. Users are auto-joined to all qualifying child rooms when they join a Space or
+   receive a new role.
+6. Cascading applies to direct parent Space only; no nested cascade through
+   sub-spaces.
+7. Feature is toggled by a single server-wide config flag
+   (`space_permission_cascading`), off by default.
+
+## Configuration
+
+```toml
+# conduwuit-example.toml
+
+# Enable space permission cascading (power levels and role-based access).
+# When enabled, power levels cascade from Spaces to child rooms and rooms
+# can require roles for access. Applies to all Spaces on this server.
+# Default: false
+space_permission_cascading = false
+```
+
+## Custom State Events
+
+All events live in the Space room.
+
+### `m.space.roles` (state key: `""`)
+
+Defines the available roles for the Space. Two default roles (`admin` and `mod`)
+are created automatically when a Space is first encountered with the feature
+enabled.
+
+```json
+{
+  "roles": {
+    "admin": {
+      "description": "Space administrator",
+      "power_level": 100
+    },
+    "mod": {
+      "description": "Space moderator",
+      "power_level": 50
+    },
+    "nsfw": {
+      "description": "Access to NSFW content"
+    },
+    "vip": {
+      "description": "VIP member"
+    }
+  }
+}
+```
+
+- `description` (string, required): Human-readable description.
+- `power_level` (integer, optional): If present, users with this role receive
+  this power level in all child rooms. When a user holds multiple roles with
+  power levels, the highest value wins.
+
+### `m.space.role.member` (state key: user ID)
+
+Assigns roles to a user within the Space.
+
+```json
+{
+  "roles": ["nsfw", "vip"]
+}
+```
+
+### `m.space.role.room` (state key: room ID)
+
+Declares which roles a child room requires. A user must hold **all** listed
+roles to access the room.
+
+```json
+{
+  "required_roles": ["nsfw"]
+}
+```
+
+## Enforcement Rules
+
+All enforcement is skipped when `space_permission_cascading = false`.
+
+### 1. Join gating
+
+When a user attempts to join a room that is a direct child of a Space:
+
+- Look up the room's `m.space.role.room` event in the parent Space.
+- If the room has `required_roles`, check the user's `m.space.role.member`.
+- Reject the join if the user is missing any required role.
+
+### 2. Power level override
+
+For every user in a child room of a Space:
+
+- Look up their roles via `m.space.role.member` in the parent Space.
+- For each role that has a `power_level`, take the highest value.
+- Override the user's power level in the child room's `m.room.power_levels`.
+- Reject attempts to manually set per-room power levels that conflict with
+  Space-granted levels.
+
+### 3. Role revocation
+
+When an `m.space.role.member` event is updated and a role is removed:
+
+- Identify all child rooms that require the removed role.
+- Auto-kick the user from rooms they no longer qualify for.
+- Recalculate and update the user's power level in all child rooms.
+
+### 4. Room requirement change
+
+When an `m.space.role.room` event is updated with new requirements:
+
+- Check all current members of the room.
+- Auto-kick members who do not hold all newly required roles.
+
+### 5. Auto-join on role grant
+
+When an `m.space.role.member` event is updated and a role is added:
+
+- Find all child rooms where the user now meets all required roles.
+- Auto-join the user to qualifying rooms they are not already in.
+
+This also applies when a user first joins the Space — they are auto-joined to
+all child rooms they qualify for. Rooms with no role requirements auto-join all
+Space members.
+
+### 6. New child room
+
+When a new `m.space.child` event is added to a Space:
+
+- Auto-join all qualifying Space members to the new child room.
+
+## Caching & Indexing
+
+The source of truth is always the state events. The server maintains an
+in-memory index for fast enforcement lookups, following the same patterns as the
+existing `roomid_spacehierarchy_cache`.
+
+### Index structures
+
+| Index                        | Source event           |
+|------------------------------|------------------------|
+| Space → roles defined        | `m.space.roles`        |
+| Space → user → roles         | `m.space.role.member`  |
+| Space → room → required roles| `m.space.role.room`    |
+| Room → parent Space          | `m.space.child` (reverse lookup) |
+
+The Space → child rooms mapping already exists.
+
+### Cache invalidation triggers
+
+| Event changed              | Action                                              |
+|----------------------------|-----------------------------------------------------|
+| `m.space.roles`            | Refresh role definitions, revalidate all members    |
+| `m.space.role.member`      | Refresh user's roles, trigger auto-join/kick        |
+| `m.space.role.room`        | Refresh room requirements, trigger auto-join/kick   |
+| `m.space.child` added      | Index new child, auto-join qualifying members       |
+| `m.space.child` removed    | Remove from index (no auto-kick)                    |
+| Server startup             | Full rebuild from state events                      |
+
+## Admin Room Commands
+
+Roles are managed via the existing admin room interface, which sends the
+appropriate state events under the hood and triggers enforcement.
+
+```
+!admin space roles list <space>
+!admin space roles add <space> <role_name> [description] [power_level]
+!admin space roles remove <space> <role_name>
+!admin space roles assign <space> <user_id> <role_name>
+!admin space roles revoke <space> <user_id> <role_name>
+!admin space roles require <space> <room_id> <role_name>
+!admin space roles unrequire <space> <room_id> <role_name>
+!admin space roles user <space> <user_id>
+!admin space roles room <space> <room_id>
+```
+
+## Architecture
+
+**Approach:** Hybrid — state events for definition, database cache for
+enforcement.
+
+- State events are the source of truth and federate normally.
+- The server maintains an in-memory cache/index for fast enforcement.
+- Cache is invalidated on relevant state event changes and fully rebuilt on
+  startup.
+- All enforcement hooks (join gating, PL override, auto-join, auto-kick) check
+  the feature flag first and no-op when disabled.
+- Existing clients can manage roles via Developer Tools (custom state events).
+  The admin room commands provide a user-friendly interface.
+
+## Scope
+
+### In scope
+
+- Server-wide feature flag
+- Custom state events for role definition, assignment, and room requirements
+- Power level cascading (Space always wins)
+- Continuous enforcement (auto-join, auto-kick)
+- Admin room commands
+- In-memory caching with invalidation
+- Default `admin` (PL 100) and `mod` (PL 50) roles
+
+### Out of scope
+
+- Client-side UI for role management
+- Nested cascade through sub-spaces
+- Per-space opt-in/opt-out (it is server-wide)
+- Federation-specific logic beyond normal state event replication

src/admin/admin.rs

@@ -11,6 +11,7 @@ use crate::{
 	query::{self, QueryCommand},
 	room::{self, RoomCommand},
 	server::{self, ServerCommand},
+	space::{self, SpaceCommand},
 	token::{self, TokenCommand},
 	user::{self, UserCommand},
 };
@@ -34,6 +35,10 @@ pub enum AdminCommand {
 	/// Commands for managing rooms
 	Rooms(RoomCommand),
 
+	#[command(subcommand)]
+	/// Commands for managing space permissions
+	Spaces(SpaceCommand),
+
 	#[command(subcommand)]
 	/// Commands for managing federation
 	Federation(FederationCommand),
@@ -81,6 +86,10 @@ pub(super) async fn process(command: AdminCommand, context: &Context<'_>) -> Res
 			token::process(command, context).await
 		},
 		| Rooms(command) => room::process(command, context).await,
+		| Spaces(command) => {
+			context.bail_restricted()?;
+			space::process(command, context).await
+		},
 		| Federation(command) => federation::process(command, context).await,
 		| Server(command) => server::process(command, context).await,
 		| Debug(command) => debug::process(command, context).await,

src/admin/mod.rs

@@ -17,6 +17,7 @@ pub(crate) mod media;
 pub(crate) mod query;
 pub(crate) mod room;
 pub(crate) mod server;
+pub(crate) mod space;
 pub(crate) mod token;
 pub(crate) mod user;
 

src/admin/space/mod.rs

@@ -0,0 +1,15 @@
+pub(super) mod roles;
+
+use clap::Subcommand;
+use conduwuit::Result;
+
+use self::roles::SpaceRolesCommand;
+use crate::admin_command_dispatch;
+
+#[admin_command_dispatch]
+#[derive(Debug, Subcommand)]
+pub enum SpaceCommand {
+	#[command(subcommand)]
+	/// Manage space roles and permissions
+	Roles(SpaceRolesCommand),
+}

src/admin/space/roles.rs

@@ -0,0 +1,632 @@
+use std::fmt::Write;
+
+use clap::Subcommand;
+use conduwuit::{Err, Event, Result, matrix::pdu::PduBuilder};
+use conduwuit_core::matrix::space_roles::{
+	RoleDefinition, SPACE_CASCADING_EVENT_TYPE, SPACE_ROLE_MEMBER_EVENT_TYPE,
+	SPACE_ROLE_ROOM_EVENT_TYPE, SPACE_ROLES_EVENT_TYPE, SpaceCascadingEventContent,
+	SpaceRoleMemberEventContent, SpaceRoleRoomEventContent, SpaceRolesEventContent,
+};
+use futures::StreamExt;
+use ruma::{OwnedRoomId, OwnedRoomOrAliasId, OwnedUserId, events::StateEventType};
+use serde_json::value::to_raw_value;
+
+use crate::{admin_command, admin_command_dispatch};
+
+fn roles_event_type() -> StateEventType {
+	StateEventType::from(SPACE_ROLES_EVENT_TYPE.to_owned())
+}
+
+fn member_event_type() -> StateEventType {
+	StateEventType::from(SPACE_ROLE_MEMBER_EVENT_TYPE.to_owned())
+}
+
+fn room_event_type() -> StateEventType {
+	StateEventType::from(SPACE_ROLE_ROOM_EVENT_TYPE.to_owned())
+}
+
+fn cascading_event_type() -> StateEventType {
+	StateEventType::from(SPACE_CASCADING_EVENT_TYPE.to_owned())
+}
+
+macro_rules! resolve_room_as_space {
+	($self:expr, $space:expr) => {{
+		let space_id = $self.services.rooms.alias.resolve(&$space).await?;
+		if !matches!(
+			$self
+				.services
+				.rooms
+				.state_accessor
+				.get_room_type(&space_id)
+				.await,
+			Ok(ruma::room::RoomType::Space)
+		) {
+			return Err!("The specified room is not a Space.");
+		}
+		space_id
+	}};
+}
+
+macro_rules! resolve_space {
+	($self:expr, $space:expr) => {{
+		let space_id = resolve_room_as_space!($self, $space);
+		if !$self
+			.services
+			.rooms
+			.roles
+			.is_enabled_for_space(&space_id)
+			.await
+		{
+			return $self
+				.write_str(
+					"Space permission cascading is disabled for this Space. Enable it \
+					 server-wide with `space_permission_cascading = true` in your config, or \
+					 per-Space with `!admin space roles enable <space>`.",
+				)
+				.await;
+		}
+		space_id
+	}};
+}
+
+macro_rules! custom_state_pdu {
+	($event_type:expr, $state_key:expr, $content:expr) => {
+		PduBuilder {
+			event_type: $event_type.to_owned().into(),
+			content: to_raw_value($content)
+				.map_err(|e| conduwuit::err!("Failed to serialize state event content: {e}"))?,
+			state_key: Some($state_key.to_owned().into()),
+			..PduBuilder::default()
+		}
+	};
+}
+
+/// Cascade-remove a role name from all state events of a given type. For each
+/// event that contains the role, the `$field` is filtered and the updated
+/// content is sent back as a new state event.
+macro_rules! cascade_remove_role {
+	(
+		$self:expr,
+		$shortstatehash:expr,
+		$event_type_fn:expr,
+		$event_type_const:expr,
+		$content_ty:ty,
+		$field:ident,
+		$role_name:expr,
+		$space_id:expr,
+		$state_lock:expr,
+		$server_user:expr
+	) => {{
+		let ev_type = $event_type_fn;
+		let entries: Vec<(_, ruma::OwnedEventId)> = $self
+			.services
+			.rooms
+			.state_accessor
+			.state_keys_with_ids($shortstatehash, &ev_type)
+			.collect()
+			.await;
+
+		for (state_key, event_id) in entries {
+			if let Ok(pdu) = $self.services.rooms.timeline.get_pdu(&event_id).await {
+				if let Ok(mut content) = pdu.get_content::<$content_ty>() {
+					if content.$field.contains($role_name) {
+						content.$field.retain(|r| r != $role_name);
+						$self
+							.services
+							.rooms
+							.timeline
+							.build_and_append_pdu(
+								custom_state_pdu!($event_type_const, &state_key, &content),
+								$server_user,
+								Some(&$space_id),
+								&$state_lock,
+							)
+							.await?;
+					}
+				}
+			}
+		}
+	}};
+}
+
+macro_rules! send_space_state {
+	($self:expr, $space_id:expr, $event_type:expr, $state_key:expr, $content:expr) => {{
+		let state_lock = $self.services.rooms.state.mutex.lock(&$space_id).await;
+		let server_user = &$self.services.globals.server_user;
+		$self
+			.services
+			.rooms
+			.timeline
+			.build_and_append_pdu(
+				custom_state_pdu!($event_type, $state_key, $content),
+				server_user,
+				Some(&$space_id),
+				&state_lock,
+			)
+			.await?
+	}};
+}
+
+#[admin_command_dispatch]
+#[derive(Debug, Subcommand)]
+pub enum SpaceRolesCommand {
+	/// List all roles defined in a space
+	List {
+		space: OwnedRoomOrAliasId,
+	},
+	/// Add a new role to a space
+	Add {
+		space: OwnedRoomOrAliasId,
+		role_name: String,
+		#[arg(long)]
+		description: Option<String>,
+		#[arg(long)]
+		power_level: Option<i64>,
+	},
+	/// Remove a role from a space
+	Remove {
+		space: OwnedRoomOrAliasId,
+		role_name: String,
+	},
+	/// Assign a role to a user
+	Assign {
+		space: OwnedRoomOrAliasId,
+		user_id: OwnedUserId,
+		role_name: String,
+	},
+	/// Revoke a role from a user
+	Revoke {
+		space: OwnedRoomOrAliasId,
+		user_id: OwnedUserId,
+		role_name: String,
+	},
+	/// Require a role for a room
+	Require {
+		space: OwnedRoomOrAliasId,
+		room_id: OwnedRoomId,
+		role_name: String,
+	},
+	/// Remove a role requirement from a room
+	Unrequire {
+		space: OwnedRoomOrAliasId,
+		room_id: OwnedRoomId,
+		role_name: String,
+	},
+	/// Show a user's roles in a space
+	User {
+		space: OwnedRoomOrAliasId,
+		user_id: OwnedUserId,
+	},
+	/// Show a room's role requirements in a space
+	Room {
+		space: OwnedRoomOrAliasId,
+		room_id: OwnedRoomId,
+	},
+	/// Enable space permission cascading for a specific space (overrides
+	/// server config)
+	Enable {
+		space: OwnedRoomOrAliasId,
+	},
+	/// Disable space permission cascading for a specific space (overrides
+	/// server config)
+	Disable {
+		space: OwnedRoomOrAliasId,
+	},
+	/// Show whether cascading is enabled for a space and the source (server
+	/// default or per-space override)
+	Status {
+		space: OwnedRoomOrAliasId,
+	},
+}
+
+#[admin_command]
+async fn list(&self, space: OwnedRoomOrAliasId) -> Result {
+	let space_id = resolve_space!(self, space);
+	let roles_event_type = roles_event_type();
+
+	let content: SpaceRolesEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &roles_event_type, "")
+		.await
+		.unwrap_or_default();
+
+	if content.roles.is_empty() {
+		return self.write_str("No roles defined in this space.").await;
+	}
+
+	let mut msg = format!("Roles in {space_id}:\n```\n");
+	for (name, def) in &content.roles {
+		let pl = def
+			.power_level
+			.map(|p| format!(" (power_level: {p})"))
+			.unwrap_or_default();
+		let _ = writeln!(msg, "- {name}: {}{pl}", def.description);
+	}
+	msg.push_str("```");
+
+	self.write_str(&msg).await
+}
+
+#[admin_command]
+async fn add(
+	&self,
+	space: OwnedRoomOrAliasId,
+	role_name: String,
+	description: Option<String>,
+	power_level: Option<i64>,
+) -> Result {
+	let space_id = resolve_space!(self, space);
+
+	if let Some(pl) = power_level {
+		if pl > i64::from(ruma::Int::MAX) || pl < i64::from(ruma::Int::MIN) {
+			return Err!(
+				"Power level must be between {} and {}.",
+				ruma::Int::MIN,
+				ruma::Int::MAX
+			);
+		}
+	}
+
+	let roles_event_type = roles_event_type();
+
+	let mut content: SpaceRolesEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &roles_event_type, "")
+		.await
+		.unwrap_or_default();
+
+	if content.roles.contains_key(&role_name) {
+		return Err!("Role '{role_name}' already exists in this space.");
+	}
+
+	content.roles.insert(role_name.clone(), RoleDefinition {
+		description: description.unwrap_or_else(|| role_name.clone()),
+		power_level,
+	});
+
+	send_space_state!(self, space_id, SPACE_ROLES_EVENT_TYPE, "", &content);
+
+	self.write_str(&format!("Added role '{role_name}' to space {space_id}."))
+		.await
+}
+
+#[admin_command]
+async fn remove(&self, space: OwnedRoomOrAliasId, role_name: String) -> Result {
+	let space_id = resolve_space!(self, space);
+	let roles_event_type = roles_event_type();
+
+	let mut content: SpaceRolesEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &roles_event_type, "")
+		.await
+		.unwrap_or_default();
+
+	if content.roles.remove(&role_name).is_none() {
+		return Err!("Role '{role_name}' does not exist in this space.");
+	}
+
+	send_space_state!(self, space_id, SPACE_ROLES_EVENT_TYPE, "", &content);
+
+	// Cascade: remove the deleted role from all member and room events
+	let server_user = &self.services.globals.server_user;
+	if let Ok(shortstatehash) = self
+		.services
+		.rooms
+		.state
+		.get_room_shortstatehash(&space_id)
+		.await
+	{
+		let state_lock = self.services.rooms.state.mutex.lock(&space_id).await;
+
+		cascade_remove_role!(
+			self,
+			shortstatehash,
+			member_event_type(),
+			SPACE_ROLE_MEMBER_EVENT_TYPE,
+			SpaceRoleMemberEventContent,
+			roles,
+			&role_name,
+			space_id,
+			state_lock,
+			server_user
+		);
+
+		cascade_remove_role!(
+			self,
+			shortstatehash,
+			room_event_type(),
+			SPACE_ROLE_ROOM_EVENT_TYPE,
+			SpaceRoleRoomEventContent,
+			required_roles,
+			&role_name,
+			space_id,
+			state_lock,
+			server_user
+		);
+	}
+
+	self.write_str(&format!("Removed role '{role_name}' from space {space_id}."))
+		.await
+}
+
+#[admin_command]
+async fn assign(
+	&self,
+	space: OwnedRoomOrAliasId,
+	user_id: OwnedUserId,
+	role_name: String,
+) -> Result {
+	let space_id = resolve_space!(self, space);
+
+	let roles_event_type = roles_event_type();
+	let role_defs: SpaceRolesEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &roles_event_type, "")
+		.await
+		.unwrap_or_default();
+
+	if !role_defs.roles.contains_key(&role_name) {
+		return Err!("Role '{role_name}' does not exist in this space.");
+	}
+
+	let member_event_type = member_event_type();
+
+	let mut content: SpaceRoleMemberEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &member_event_type, user_id.as_str())
+		.await
+		.unwrap_or_default();
+
+	if content.roles.contains(&role_name) {
+		return Err!("User {user_id} already has role '{role_name}' in this space.");
+	}
+
+	content.roles.push(role_name.clone());
+
+	send_space_state!(self, space_id, SPACE_ROLE_MEMBER_EVENT_TYPE, user_id.as_str(), &content);
+
+	self.write_str(&format!("Assigned role '{role_name}' to {user_id} in space {space_id}."))
+		.await
+}
+
+#[admin_command]
+async fn revoke(
+	&self,
+	space: OwnedRoomOrAliasId,
+	user_id: OwnedUserId,
+	role_name: String,
+) -> Result {
+	let space_id = resolve_space!(self, space);
+	let member_event_type = member_event_type();
+
+	let mut content: SpaceRoleMemberEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &member_event_type, user_id.as_str())
+		.await
+		.unwrap_or_default();
+
+	let original_len = content.roles.len();
+	content.roles.retain(|r| r != &role_name);
+
+	if content.roles.len() == original_len {
+		return Err!("User {user_id} does not have role '{role_name}' in this space.");
+	}
+
+	send_space_state!(self, space_id, SPACE_ROLE_MEMBER_EVENT_TYPE, user_id.as_str(), &content);
+
+	self.write_str(&format!("Revoked role '{role_name}' from {user_id} in space {space_id}."))
+		.await
+}
+
+#[admin_command]
+async fn require(
+	&self,
+	space: OwnedRoomOrAliasId,
+	room_id: OwnedRoomId,
+	role_name: String,
+) -> Result {
+	let space_id = resolve_space!(self, space);
+
+	let child_rooms = self.services.rooms.roles.get_child_rooms(&space_id).await;
+	if !child_rooms.contains(&room_id) {
+		return Err!("Room {room_id} is not a child of space {space_id}.");
+	}
+
+	let roles_event_type = roles_event_type();
+	let role_defs: SpaceRolesEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &roles_event_type, "")
+		.await
+		.unwrap_or_default();
+
+	if !role_defs.roles.contains_key(&role_name) {
+		return Err!("Role '{role_name}' does not exist in this space.");
+	}
+
+	let room_event_type = room_event_type();
+
+	let mut content: SpaceRoleRoomEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &room_event_type, room_id.as_str())
+		.await
+		.unwrap_or_default();
+
+	if content.required_roles.contains(&role_name) {
+		return Err!("Room {room_id} already requires role '{role_name}' in this space.");
+	}
+
+	content.required_roles.push(role_name.clone());
+
+	send_space_state!(self, space_id, SPACE_ROLE_ROOM_EVENT_TYPE, room_id.as_str(), &content);
+
+	self.write_str(&format!(
+		"Room {room_id} now requires role '{role_name}' in space {space_id}."
+	))
+	.await
+}
+
+#[admin_command]
+async fn unrequire(
+	&self,
+	space: OwnedRoomOrAliasId,
+	room_id: OwnedRoomId,
+	role_name: String,
+) -> Result {
+	let space_id = resolve_space!(self, space);
+	let room_event_type = room_event_type();
+
+	let mut content: SpaceRoleRoomEventContent = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content(&space_id, &room_event_type, room_id.as_str())
+		.await
+		.unwrap_or_default();
+
+	let original_len = content.required_roles.len();
+	content.required_roles.retain(|r| r != &role_name);
+
+	if content.required_roles.len() == original_len {
+		return Err!("Room {room_id} does not require role '{role_name}' in this space.");
+	}
+
+	send_space_state!(self, space_id, SPACE_ROLE_ROOM_EVENT_TYPE, room_id.as_str(), &content);
+
+	self.write_str(&format!(
+		"Removed role requirement '{role_name}' from room {room_id} in space {space_id}."
+	))
+	.await
+}
+
+#[admin_command]
+async fn user(&self, space: OwnedRoomOrAliasId, user_id: OwnedUserId) -> Result {
+	let space_id = resolve_space!(self, space);
+
+	let roles = self
+		.services
+		.rooms
+		.roles
+		.get_user_roles_in_space(&space_id, &user_id)
+		.await;
+
+	match roles {
+		| Some(roles) if !roles.is_empty() => {
+			let list: String = roles
+				.iter()
+				.map(|r| format!("- {r}"))
+				.collect::<Vec<_>>()
+				.join("\n");
+			self.write_str(&format!("Roles for {user_id} in space {space_id}:\n```\n{list}\n```"))
+				.await
+		},
+		| _ =>
+			self.write_str(&format!("User {user_id} has no roles in space {space_id}."))
+				.await,
+	}
+}
+
+#[admin_command]
+async fn room(&self, space: OwnedRoomOrAliasId, room_id: OwnedRoomId) -> Result {
+	let space_id = resolve_space!(self, space);
+
+	let reqs = self
+		.services
+		.rooms
+		.roles
+		.get_room_requirements_in_space(&space_id, &room_id)
+		.await;
+
+	match reqs {
+		| Some(reqs) if !reqs.is_empty() => {
+			let list: String = reqs
+				.iter()
+				.map(|r| format!("- {r}"))
+				.collect::<Vec<_>>()
+				.join("\n");
+			self.write_str(&format!(
+				"Required roles for room {room_id} in space {space_id}:\n```\n{list}\n```"
+			))
+			.await
+		},
+		| _ =>
+			self.write_str(&format!(
+				"Room {room_id} has no role requirements in space {space_id}."
+			))
+			.await,
+	}
+}
+
+#[admin_command]
+async fn enable(&self, space: OwnedRoomOrAliasId) -> Result {
+	let space_id = resolve_room_as_space!(self, space);
+
+	self.services
+		.rooms
+		.roles
+		.ensure_default_roles(&space_id)
+		.await?;
+
+	let content = SpaceCascadingEventContent { enabled: true };
+	send_space_state!(self, space_id, SPACE_CASCADING_EVENT_TYPE, "", &content);
+
+	self.write_str(&format!("Space permission cascading enabled for {space_id}."))
+		.await
+}
+
+#[admin_command]
+async fn disable(&self, space: OwnedRoomOrAliasId) -> Result {
+	let space_id = resolve_room_as_space!(self, space);
+
+	let content = SpaceCascadingEventContent { enabled: false };
+	send_space_state!(self, space_id, SPACE_CASCADING_EVENT_TYPE, "", &content);
+
+	self.write_str(&format!("Space permission cascading disabled for {space_id}."))
+		.await
+}
+
+#[admin_command]
+async fn status(&self, space: OwnedRoomOrAliasId) -> Result {
+	let space_id = resolve_room_as_space!(self, space);
+
+	let global_default = self.services.rooms.roles.is_enabled();
+	let cascading_event_type = cascading_event_type();
+	let per_space_override: Option<bool> = self
+		.services
+		.rooms
+		.state_accessor
+		.room_state_get_content::<SpaceCascadingEventContent>(
+			&space_id,
+			&cascading_event_type,
+			"",
+		)
+		.await
+		.ok()
+		.map(|c| c.enabled);
+
+	let effective = per_space_override.unwrap_or(global_default);
+	let source = match per_space_override {
+		| Some(v) => format!("per-Space override (enabled: {v})"),
+		| None => format!("server default (space_permission_cascading: {global_default})"),
+	};
+
+	self.write_str(&format!(
+		"Cascading status for {space_id}:\n- Effective: **{effective}**\n- Source: {source}"
+	))
+	.await
+}

src/api/client/membership/join.rs

@@ -347,6 +347,12 @@ pub async fn join_room_by_id_helper(
 		}
 	}
 
+	services
+		.rooms
+		.roles
+		.check_join_allowed(room_id, sender_user)
+		.await?;
+
 	if server_in_room {
 		join_room_by_id_helper_local(services, sender_user, room_id, reason, servers, state_lock)
 			.boxed()

src/core/config/mod.rs

@@ -603,6 +603,22 @@ pub struct Config {
 	#[serde(default)]
 	pub suspend_on_register: bool,
 
+	/// Server-wide default for space permission cascading (power levels and
+	/// role-based access). Individual Spaces can override this via the
+	/// `com.continuwuity.space.cascading` state event or the admin command
+	/// `!admin space roles enable/disable <space>`.
+	///
+	/// default: false
+	#[serde(default)]
+	pub space_permission_cascading: bool,
+
+	/// Maximum number of spaces to cache role data for. When exceeded the
+	/// cache is cleared and repopulated on demand.
+	///
+	/// default: 1000
+	#[serde(default = "default_space_roles_cache_flush_threshold")]
+	pub space_roles_cache_flush_threshold: u32,
+
 	/// Enabling this setting opens registration to anyone without restrictions.
 	/// This makes your server vulnerable to abuse
 	#[serde(default)]
@@ -2826,3 +2842,5 @@ fn default_ldap_search_filter() -> String { "(objectClass=*)".to_owned() }
 fn default_ldap_uid_attribute() -> String { String::from("uid") }
 
 fn default_ldap_name_attribute() -> String { String::from("givenName") }
+
+fn default_space_roles_cache_flush_threshold() -> u32 { 1000 }

src/core/matrix/mod.rs

@@ -2,6 +2,7 @@
 
 pub mod event;
 pub mod pdu;
+pub mod space_roles;
 pub mod state_key;
 pub mod state_res;
 

src/core/matrix/space_roles.rs

@@ -0,0 +1,81 @@
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+
+pub const SPACE_ROLES_EVENT_TYPE: &str = "com.continuwuity.space.roles";
+pub const SPACE_ROLE_MEMBER_EVENT_TYPE: &str = "com.continuwuity.space.role.member";
+pub const SPACE_ROLE_ROOM_EVENT_TYPE: &str = "com.continuwuity.space.role.room";
+pub const SPACE_CASCADING_EVENT_TYPE: &str = "com.continuwuity.space.cascading";
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize, PartialEq, Eq)]
+pub struct SpaceRolesEventContent {
+	pub roles: BTreeMap<String, RoleDefinition>,
+}
+
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
+pub struct RoleDefinition {
+	pub description: String,
+	#[serde(skip_serializing_if = "Option::is_none")]
+	pub power_level: Option<i64>,
+}
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize, PartialEq, Eq)]
+pub struct SpaceRoleMemberEventContent {
+	pub roles: Vec<String>,
+}
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize, PartialEq, Eq)]
+pub struct SpaceRoleRoomEventContent {
+	pub required_roles: Vec<String>,
+}
+
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
+pub struct SpaceCascadingEventContent {
+	pub enabled: bool,
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn space_roles_roundtrip() {
+		let mut roles = BTreeMap::new();
+		roles.insert("admin".to_owned(), RoleDefinition {
+			description: "Space administrator".to_owned(),
+			power_level: Some(100),
+		});
+		roles.insert("nsfw".to_owned(), RoleDefinition {
+			description: "NSFW access".to_owned(),
+			power_level: None,
+		});
+		let content = SpaceRolesEventContent { roles };
+		let json = serde_json::to_string(&content).unwrap();
+		let deserialized: SpaceRolesEventContent = serde_json::from_str(&json).unwrap();
+		assert_eq!(deserialized.roles["admin"].power_level, Some(100));
+		assert!(deserialized.roles["nsfw"].power_level.is_none());
+	}
+
+	#[test]
+	fn power_level_omitted_in_serialization_when_none() {
+		let role = RoleDefinition {
+			description: "Test".to_owned(),
+			power_level: None,
+		};
+		let json = serde_json::to_string(&role).unwrap();
+		assert!(!json.contains("power_level"));
+	}
+
+	#[test]
+	fn negative_power_level() {
+		let json = r#"{"description":"Restricted","power_level":-10}"#;
+		let role: RoleDefinition = serde_json::from_str(json).unwrap();
+		assert_eq!(role.power_level, Some(-10));
+	}
+
+	#[test]
+	fn missing_description_fails() {
+		let json = r#"{"power_level":100}"#;
+		serde_json::from_str::<RoleDefinition>(json).unwrap_err();
+	}
+}

src/service/rooms/mod.rs

@@ -7,6 +7,7 @@ pub mod metadata;
 pub mod outlier;
 pub mod pdu_metadata;
 pub mod read_receipt;
+pub mod roles;
 pub mod search;
 pub mod short;
 pub mod spaces;
@@ -31,6 +32,7 @@ pub struct Service {
 	pub outlier: Arc<outlier::Service>,
 	pub pdu_metadata: Arc<pdu_metadata::Service>,
 	pub read_receipt: Arc<read_receipt::Service>,
+	pub roles: Arc<roles::Service>,
 	pub search: Arc<search::Service>,
 	pub short: Arc<short::Service>,
 	pub spaces: Arc<spaces::Service>,

src/service/rooms/roles/tests.rs

@@ -0,0 +1,204 @@
+use std::collections::{BTreeMap, HashSet};
+
+use conduwuit_core::matrix::space_roles::RoleDefinition;
+
+use super::{compute_user_power_level, roles_satisfy_requirements};
+
+pub(super) fn make_roles(entries: &[(&str, Option<i64>)]) -> BTreeMap<String, RoleDefinition> {
+	entries
+		.iter()
+		.map(|(name, pl)| {
+			((*name).to_owned(), RoleDefinition {
+				description: format!("{name} role"),
+				power_level: *pl,
+			})
+		})
+		.collect()
+}
+
+pub(super) fn make_set(items: &[&str]) -> HashSet<String> {
+	items.iter().map(|s| (*s).to_owned()).collect()
+}
+
+#[test]
+fn power_level_single_role() {
+	let roles = make_roles(&[("admin", Some(100)), ("mod", Some(50))]);
+	assert_eq!(compute_user_power_level(&roles, &make_set(&["admin"])), Some(100));
+}
+
+#[test]
+fn power_level_multiple_roles_takes_highest() {
+	let roles = make_roles(&[("admin", Some(100)), ("mod", Some(50)), ("helper", Some(25))]);
+	assert_eq!(compute_user_power_level(&roles, &make_set(&["mod", "helper"])), Some(50));
+}
+
+#[test]
+fn power_level_no_power_roles() {
+	let roles = make_roles(&[("nsfw", None), ("vip", None)]);
+	assert_eq!(compute_user_power_level(&roles, &make_set(&["nsfw", "vip"])), None);
+}
+
+#[test]
+fn power_level_mixed_roles() {
+	let roles = make_roles(&[("mod", Some(50)), ("nsfw", None)]);
+	assert_eq!(compute_user_power_level(&roles, &make_set(&["mod", "nsfw"])), Some(50));
+}
+
+#[test]
+fn power_level_no_roles_assigned() {
+	let roles = make_roles(&[("admin", Some(100))]);
+	assert_eq!(compute_user_power_level(&roles, &HashSet::new()), None);
+}
+
+#[test]
+fn power_level_unknown_role_ignored() {
+	let roles = make_roles(&[("admin", Some(100))]);
+	assert_eq!(compute_user_power_level(&roles, &make_set(&["nonexistent"])), None);
+}
+
+#[test]
+fn qualifies_with_all_required_roles() {
+	assert!(roles_satisfy_requirements(
+		&make_set(&["nsfw", "vip"]),
+		&make_set(&["nsfw", "vip", "extra"]),
+	));
+}
+
+#[test]
+fn does_not_qualify_missing_one_role() {
+	assert!(!roles_satisfy_requirements(&make_set(&["nsfw", "vip"]), &make_set(&["nsfw"]),));
+}
+
+#[test]
+fn qualifies_with_no_requirements() {
+	assert!(roles_satisfy_requirements(&HashSet::new(), &make_set(&["nsfw"])));
+}
+
+#[test]
+fn does_not_qualify_with_no_roles() {
+	assert!(!roles_satisfy_requirements(&make_set(&["nsfw"]), &HashSet::new()));
+}
+
+// Multi-space scenarios
+
+#[test]
+fn multi_space_highest_pl_wins() {
+	let space_a_roles = make_roles(&[("mod", Some(50))]);
+	let space_b_roles = make_roles(&[("admin", Some(100))]);
+
+	let user_roles_a = make_set(&["mod"]);
+	let user_roles_b = make_set(&["admin"]);
+
+	let pl_a = compute_user_power_level(&space_a_roles, &user_roles_a);
+	let pl_b = compute_user_power_level(&space_b_roles, &user_roles_b);
+
+	let effective = [pl_a, pl_b].into_iter().flatten().max();
+	assert_eq!(effective, Some(100));
+}
+
+#[test]
+fn multi_space_one_space_has_no_pl() {
+	let space_a_roles = make_roles(&[("nsfw", None)]);
+	let space_b_roles = make_roles(&[("mod", Some(50))]);
+
+	let user_roles_a = make_set(&["nsfw"]);
+	let user_roles_b = make_set(&["mod"]);
+
+	let pl_a = compute_user_power_level(&space_a_roles, &user_roles_a);
+	let pl_b = compute_user_power_level(&space_b_roles, &user_roles_b);
+
+	let effective = [pl_a, pl_b].into_iter().flatten().max();
+	assert_eq!(effective, Some(50));
+}
+
+#[test]
+fn multi_space_neither_has_pl() {
+	let space_a_roles = make_roles(&[("nsfw", None)]);
+	let space_b_roles = make_roles(&[("vip", None)]);
+
+	let user_roles_a = make_set(&["nsfw"]);
+	let user_roles_b = make_set(&["vip"]);
+
+	let pl_a = compute_user_power_level(&space_a_roles, &user_roles_a);
+	let pl_b = compute_user_power_level(&space_b_roles, &user_roles_b);
+
+	let effective = [pl_a, pl_b].into_iter().flatten().max();
+	assert_eq!(effective, None);
+}
+
+#[test]
+fn multi_space_user_only_in_one_space() {
+	let space_a_roles = make_roles(&[("admin", Some(100))]);
+	let space_b_roles = make_roles(&[("mod", Some(50))]);
+
+	let user_roles_a = make_set(&["admin"]);
+	let user_roles_b: HashSet<String> = HashSet::new();
+
+	let pl_a = compute_user_power_level(&space_a_roles, &user_roles_a);
+	let pl_b = compute_user_power_level(&space_b_roles, &user_roles_b);
+
+	let effective = [pl_a, pl_b].into_iter().flatten().max();
+	assert_eq!(effective, Some(100));
+}
+
+#[test]
+fn multi_space_qualifies_in_one_not_other() {
+	let space_a_reqs = make_set(&["staff"]);
+	let space_b_reqs = make_set(&["nsfw"]);
+
+	let user_roles = make_set(&["nsfw"]);
+
+	assert!(!roles_satisfy_requirements(&space_a_reqs, &user_roles));
+	assert!(roles_satisfy_requirements(&space_b_reqs, &user_roles));
+}
+
+#[test]
+fn multi_space_qualifies_after_role_revoke_via_other_space() {
+	let space_a_reqs = make_set(&["nsfw"]);
+	let space_b_reqs = make_set(&["vip"]);
+
+	let user_roles_after_revoke = make_set(&["vip"]);
+
+	assert!(!roles_satisfy_requirements(&space_a_reqs, &user_roles_after_revoke));
+	assert!(roles_satisfy_requirements(&space_b_reqs, &user_roles_after_revoke));
+}
+
+#[test]
+fn multi_space_room_has_reqs_in_one_space_only() {
+	let space_a_reqs = make_set(&["admin"]);
+	let space_b_reqs: HashSet<String> = HashSet::new();
+
+	let user_roles = make_set(&["nsfw"]);
+
+	assert!(!roles_satisfy_requirements(&space_a_reqs, &user_roles));
+	assert!(roles_satisfy_requirements(&space_b_reqs, &user_roles));
+}
+
+#[test]
+fn multi_space_no_qualification_anywhere() {
+	let space_a_reqs = make_set(&["staff"]);
+	let space_b_reqs = make_set(&["admin"]);
+
+	let user_roles = make_set(&["nsfw"]);
+
+	let qualifies_a = roles_satisfy_requirements(&space_a_reqs, &user_roles);
+	let qualifies_b = roles_satisfy_requirements(&space_b_reqs, &user_roles);
+
+	assert!(!qualifies_a);
+	assert!(!qualifies_b);
+	assert!(!(qualifies_a || qualifies_b));
+}
+
+#[test]
+fn multi_space_same_role_different_pl() {
+	let space_a_roles = make_roles(&[("mod", Some(50))]);
+	let space_b_roles = make_roles(&[("mod", Some(75))]);
+
+	let user_roles = make_set(&["mod"]);
+
+	let pl_a = compute_user_power_level(&space_a_roles, &user_roles);
+	let pl_b = compute_user_power_level(&space_b_roles, &user_roles);
+
+	let effective = [pl_a, pl_b].into_iter().flatten().max();
+	assert_eq!(effective, Some(75));
+}

src/service/rooms/timeline/append.rs

@@ -327,7 +327,7 @@ where
 			}
 		},
 		| TimelineEventType::SpaceChild =>
-			if let Some(_state_key) = pdu.state_key() {
+			if pdu.state_key().is_some() {
 				self.services
 					.spaces
 					.roomid_spacehierarchy_cache
@@ -359,6 +359,8 @@ where
 		| _ => {},
 	}
 
+	self.services.roles.on_pdu_appended(room_id, &pdu);
+
 	// CONCERN: If we receive events with a relation out-of-order, we never write
 	// their relation / thread. We need some kind of way to trigger when we receive
 	// this event, and potentially a way to rebuild the table entirely.

src/service/rooms/timeline/build.rs

@@ -97,6 +97,17 @@ pub async fn build_and_append_pdu(
 			)));
 		}
 	}
+	if *pdu.kind() == TimelineEventType::RoomPowerLevels {
+		if let Ok(proposed) =
+			pdu.get_content::<ruma::events::room::power_levels::RoomPowerLevelsEventContent>()
+		{
+			self.services
+				.roles
+				.validate_pl_change(&room_id, pdu.sender(), &proposed)
+				.await?;
+		}
+	}
+
 	if *pdu.kind() == TimelineEventType::RoomCreate {
 		trace!("Creating shortroomid for {room_id}");
 		self.services

src/service/rooms/timeline/mod.rs

@@ -80,6 +80,7 @@ struct Services {
 	threads: Dep<rooms::threads::Service>,
 	search: Dep<rooms::search::Service>,
 	spaces: Dep<rooms::spaces::Service>,
+	roles: Dep<rooms::roles::Service>,
 	event_handler: Dep<rooms::event_handler::Service>,
 }
 
@@ -112,6 +113,7 @@ impl crate::Service for Service {
 				threads: args.depend::<rooms::threads::Service>("rooms::threads"),
 				search: args.depend::<rooms::search::Service>("rooms::search"),
 				spaces: args.depend::<rooms::spaces::Service>("rooms::spaces"),
+				roles: args.depend::<rooms::roles::Service>("rooms::roles"),
 				event_handler: args
 					.depend::<rooms::event_handler::Service>("rooms::event_handler"),
 			},

src/service/services.rs

@@ -94,6 +94,7 @@ impl Services {
 				outlier: build!(rooms::outlier::Service),
 				pdu_metadata: build!(rooms::pdu_metadata::Service),
 				read_receipt: build!(rooms::read_receipt::Service),
+				roles: build!(rooms::roles::Service),
 				search: build!(rooms::search::Service),
 				short: build!(rooms::short::Service),
 				spaces: build!(rooms::spaces::Service),