save: add utoipa for OAPI generation

blah-types/Cargo.toml

@@ -6,6 +6,11 @@ edition = "2021"
 [features]
 default = []
 unsafe_use_mock_instant_for_testing = ["dep:mock_instant"]
+utoipa = ["dep:utoipa"]
+
+[[example]]
+name = "openapi"
+required-features = ["utoipa"]
 
 [[bench]]
 name = "crypto_ops"
@@ -26,6 +31,7 @@ serde_json = "1"
 serde_with = "3"
 thiserror = "1"
 url = { version = "2", features = ["serde"] }
+utoipa = { workspace = true, optional = true, features = ["url"] } # Generics support.
 
 [dev-dependencies]
 criterion = "0.5"

blah-types/examples/openapi.rs

@@ -0,0 +1,8 @@
+#![expect(clippy::print_stdout, reason = "allowed to dump OAPI")]
+
+fn main() {
+    let json = blah_types::openapi()
+        .to_pretty_json()
+        .expect("serialization cannot fail");
+    println!("{json}");
+}

blah-types/src/crypto.rs

@@ -11,6 +11,7 @@ use rand::RngCore;
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct UserKey {
     pub id_key: PubKey,
     pub act_key: PubKey,
@@ -18,6 +19,7 @@ pub struct UserKey {
 
 #[derive(Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(transparent)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = String))]
 pub struct PubKey(#[serde(with = "hex::serde")] pub [u8; PUBLIC_KEY_LENGTH]);
 
 impl FromStr for PubKey {
@@ -55,14 +57,17 @@ impl From<&VerifyingKey> for PubKey {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(deny_unknown_fields)]
 pub struct Signed<T> {
     #[serde(with = "hex::serde")]
+    #[cfg_attr(feature = "utoipa", schema(value_type = String))]
     pub sig: [u8; SIGNATURE_LENGTH],
     pub signee: Signee<T>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(deny_unknown_fields)]
 pub struct Signee<T> {
     pub nonce: u32,

blah-types/src/identity.rs

@@ -12,6 +12,7 @@ use crate::{PubKey, Signed};
 /// User identity description structure.
 // TODO: Revise and shrink duplicates (pubkey fields).
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct UserIdentityDesc {
     /// User primary identity key, only for signing action keys.
     pub id_key: PubKey,
@@ -90,6 +91,7 @@ impl UserIdentityDesc {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename = "user_act_key")]
 pub struct UserActKeyDesc {
     pub act_key: PubKey,
@@ -98,6 +100,7 @@ pub struct UserActKeyDesc {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename = "user_profile")]
 pub struct UserProfile {
     pub preferred_chat_server_urls: Vec<Url>,
@@ -105,6 +108,7 @@ pub struct UserProfile {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = Url))]
 #[serde(try_from = "Url")]
 pub struct IdUrl(Url);
 

blah-types/src/lib.rs

@@ -10,3 +10,46 @@ pub mod crypto;
 pub mod identity;
 pub mod msg;
 pub mod server;
+
+#[cfg(feature = "utoipa")]
+pub fn openapi() -> utoipa::openapi::OpenApi {
+    use utoipa::OpenApi;
+
+    #[derive(OpenApi)]
+    #[openapi(components(schemas(
+        crypto::Signed::<msg::AuthPayload>,
+        crypto::Signed::<msg::ChatPayload>,
+        crypto::Signed::<msg::CreateRoomPayload>,
+        crypto::Signed::<msg::DeleteRoomPayload>,
+        crypto::Signed::<msg::RoomAdminPayload>,
+        crypto::Signed::<msg::UserRegisterPayload>,
+        identity::UserIdentityDesc,
+        identity::UserProfile,
+        msg::AuthPayload,
+        msg::ChatPayload,
+        msg::DeleteRoomPayload,
+        msg::RichText,
+        msg::RoomAdminPayload,
+        msg::UserRegisterPayload,
+        server::ClientEvent,
+        server::ErrorResponse,
+        server::ErrorResponseWithChallenge,
+        server::RoomList,
+        server::RoomMetadata,
+        server::RoomMsgs,
+        server::ServerCapabilities,
+        server::ServerEvent,
+        server::ServerMetadata,
+    )))]
+    struct ApiDoc;
+
+    ApiDoc::openapi()
+}
+
+#[cfg(feature = "utoipa")]
+#[test]
+#[expect(clippy::print_stdout, reason = "allowed in tests")]
+fn test_openapi() {
+    let json = crate::openapi().to_pretty_json().unwrap();
+    println!("{json}");
+}

blah-types/src/msg.rs

@@ -15,6 +15,7 @@ use crate::{PubKey, Signed};
 /// It's currently serialized as a string for JavaScript's convenience.
 #[serde_as]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = String))]
 #[serde(transparent)]
 pub struct Id(#[serde_as(as = "DisplayFromStr")] pub i64);
 
@@ -39,6 +40,7 @@ impl Id {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct WithMsgId<T> {
     pub cid: Id,
     #[serde(flatten)]
@@ -53,17 +55,20 @@ impl<T> WithMsgId<T> {
 
 /// Register a user on a chat server.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename = "user_register")]
 pub struct UserRegisterPayload {
     pub server_url: Url,
     pub id_url: IdUrl,
     pub id_key: PubKey,
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub challenge: Option<UserRegisterChallengeResponse>,
 }
 
 /// The server-specific challenge data for registration.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(rename_all = "snake_case")]
 pub enum UserRegisterChallengeResponse {
     /// Proof of work challenge containing the same nonce from server challenge request.
@@ -73,6 +78,7 @@ pub enum UserRegisterChallengeResponse {
 
 // FIXME: `deny_unknown_fields` breaks this.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename = "chat")]
 pub struct ChatPayload {
     pub rich_text: RichText,
@@ -81,6 +87,7 @@ pub struct ChatPayload {
 
 /// Ref: <https://github.com/Blah-IM/Weblah/blob/a3fa0f265af54c846f8d65f42aa4409c8dba9dd9/src/lib/richText.ts>
 #[derive(Debug, Clone, Default, PartialEq, Eq, Serialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = Vec<RichTextPieceRaw>))]
 #[serde(transparent)]
 pub struct RichText(pub Vec<RichTextPiece>);
 
@@ -103,8 +110,9 @@ impl Serialize for RichTextPiece {
     }
 }
 
-/// The protocol representation of `RichTextPiece`.
+/// The representation on wire of `RichTextPiece`.
 #[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(untagged)]
 enum RichTextPieceRaw {
     Text(String),
@@ -148,6 +156,7 @@ impl<'de> Deserialize<'de> for RichText {
 
 // TODO: This protocol format is quite large. Could use bitflags for database.
 #[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct TextAttrs {
     #[serde(default, rename = "b", skip_serializing_if = "is_default")]
     pub bold: bool,
@@ -159,6 +168,7 @@ pub struct TextAttrs {
     pub italic: bool,
     // TODO: Should we validate and/or filter the URL.
     #[serde(default, skip_serializing_if = "is_default")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub link: Option<String>,
     #[serde(default, rename = "s", skip_serializing_if = "is_default")]
     pub strike: bool,
@@ -271,6 +281,7 @@ pub type SignedChatMsg = Signed<ChatPayload>;
 pub type SignedChatMsgWithId = WithMsgId<SignedChatMsg>;
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ")]
 pub enum CreateRoomPayload {
     #[serde(rename = "create_room")]
@@ -281,6 +292,7 @@ pub enum CreateRoomPayload {
 
 /// Multi-user room.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct CreateGroup {
     pub attrs: RoomAttrs,
     pub title: String,
@@ -288,11 +300,13 @@ pub struct CreateGroup {
 
 /// Peer-to-peer chat room with exactly two symmetric users.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct CreatePeerChat {
     pub peer: PubKey,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename = "delete_room")]
 pub struct DeleteRoomPayload {
     pub room: Id,
@@ -302,6 +316,7 @@ pub struct DeleteRoomPayload {
 /// 1. Sorted by userkeys.
 /// 2. No duplicated users.
 #[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(try_from = "Vec<RoomMember>")]
 pub struct RoomMemberList(pub Vec<RoomMember>);
 
@@ -327,6 +342,7 @@ impl TryFrom<Vec<RoomMember>> for RoomMemberList {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct RoomMember {
     pub permission: MemberPermission,
     pub user: PubKey,
@@ -336,11 +352,13 @@ pub struct RoomMember {
 ///
 /// TODO: Should we use JWT here instead?
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename = "auth")]
 pub struct AuthPayload {}
 
 // FIXME: Remove this.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 // `typ` is provided by `RoomAdminOp`.
 pub struct RoomAdminPayload {
     #[serde(flatten)]
@@ -348,6 +366,7 @@ pub struct RoomAdminPayload {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename_all = "snake_case", rename = "remove_member")]
 pub struct RemoveMemberPayload {
     pub room: Id,
@@ -357,6 +376,7 @@ pub struct RemoveMemberPayload {
 
 // TODO: Maybe disallow adding other user without consent?
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename_all = "snake_case", rename = "add_member")]
 pub struct AddMemberPayload {
     pub room: Id,
@@ -365,6 +385,7 @@ pub struct AddMemberPayload {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(tag = "typ", rename_all = "snake_case", rename = "update_member")]
 pub struct UpdateMemberPayload {
     pub room: Id,
@@ -373,6 +394,7 @@ pub struct UpdateMemberPayload {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(untagged)]
 pub enum RoomAdminOp {
     AddMember(AddMemberPayload),
@@ -382,6 +404,7 @@ pub enum RoomAdminOp {
 bitflags::bitflags! {
     /// TODO: Is this a really all about permission, or is a generic `UserFlags`?
     #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    #[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = i32))]
     pub struct ServerPermission: i32 {
         const CREATE_ROOM = 1 << 0;
 
@@ -391,6 +414,7 @@ bitflags::bitflags! {
     }
 
     #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    #[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = i32))]
     pub struct MemberPermission: i32 {
         const POST_CHAT = 1 << 0;
         const ADD_MEMBER = 1 << 1;
@@ -410,6 +434,7 @@ bitflags::bitflags! {
     }
 
     #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+    #[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema), schema(value_type = i32))]
     pub struct RoomAttrs: i32 {
         // NB. Used by schema.
         const PUBLIC_READABLE = 1 << 0;

blah-types/src/server.rs

@@ -10,6 +10,7 @@ use crate::PubKey;
 
 /// The response object returned as body on HTTP error status.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct ErrorResponse<S = String> {
     /// The error object.
     pub error: ErrorObject<S>,
@@ -18,21 +19,27 @@ pub struct ErrorResponse<S = String> {
 /// The response object of `/_blah/user/me` endpoint on HTTP error status.
 /// It contains additional registration information.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct ErrorResponseWithChallenge<S = String> {
     /// The error object.
     pub error: ErrorObject<S>,
 
     /// The challenge metadata returned by the `/_blah/user/me` endpoint for registration.
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub register_challenge: Option<UserRegisterChallenge>,
 }
 
 /// The error object.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct ErrorObject<S = String> {
     /// A machine-readable error code string.
+    #[cfg_attr(feature = "utoipa", schema(value_type = String, example = "user_not_found"))]
     pub code: S,
+
     /// A human-readable error message.
+    #[cfg_attr(feature = "utoipa", schema(value_type = String, example = "the user does not exist"))]
     pub message: S,
 }
 
@@ -50,16 +57,20 @@ impl<S: fmt::Display + fmt::Debug> std::error::Error for ErrorObject<S> {}
 /// It may contains extra fields and clients should ignore them for future compatibility.
 /// Chat Servers can also include any custom fields here as long they have a `_` prefix.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct ServerMetadata {
     /// A server-defined version string indicating its implementation name and the version.
     ///
     /// It is expected to be in form `<server-name>/<server-version>` but not mandatory.
+    #[cfg_attr(feature = "utoipa", schema(example = "blahd/0.0.1"))]
     pub server: String,
 
     /// The URL to the source code of the Chat Server.
     ///
     /// It is expected to be a public accessible maybe-compressed tarball link without
     /// access control.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub src_url: Option<Url>,
 
     /// The server capabilities set.
@@ -67,6 +78,7 @@ pub struct ServerMetadata {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct ServerCapabilities {
     /// Whether registration is open to public.
     pub allow_public_register: bool,
@@ -74,6 +86,7 @@ pub struct ServerCapabilities {
 
 /// Registration challenge information.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(rename_all = "snake_case")]
 pub enum UserRegisterChallenge {
     /// Proof-of-work (PoW) challenge.
@@ -86,67 +99,82 @@ pub enum UserRegisterChallenge {
 
 /// Response to list rooms.
 #[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct RoomList {
     /// Result list of rooms.
     pub rooms: Vec<RoomMetadata>,
     /// The skip-token to fetch the next page.
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub skip_token: Option<Id>,
 }
 
 /// The metadata of a room.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct RoomMetadata {
     /// Room id.
     pub rid: Id,
     /// Plain text room title. None for peer chat.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub title: Option<String>,
     /// Room attributes.
     pub attrs: RoomAttrs,
 
     // Extra information is only available for some APIs.
     /// The last message in the room.
-    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub last_msg: Option<SignedChatMsgWithId>,
     /// The current user's last seen message's `cid`.
-    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub last_seen_cid: Option<Id>,
     /// The number of unseen messages, ie. the number of messages from `last_seen_cid` to
     /// `last_msg.cid`.
     /// This may or may not be a precise number.
-    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub unseen_cnt: Option<u32>,
     /// The member permission of current user in the room, or `None` if it is not a member.
     /// Only available with authentication.
-    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub member_permission: Option<MemberPermission>,
     /// The peer user, if this is a peer chat room.
-    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub peer_user: Option<PubKey>,
 }
 
 /// Response to list room msgs.
 #[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct RoomMsgs {
     /// Result list of msgs.
     pub msgs: Vec<SignedChatMsgWithId>,
     /// The skip-token to fetch the next page.
-    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub skip_token: Option<Id>,
 }
 
 /// Response to list room members.
 #[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct RoomMemberList {
     /// Result list of members.
     pub members: Vec<RoomMember>,
     /// The skip-token to fetch the next page.
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub skip_token: Option<Id>,
 }
 
 /// The description of a room member.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 pub struct RoomMember {
     /// The identity key of the member user.
     pub id_key: PubKey,
@@ -154,11 +182,13 @@ pub struct RoomMember {
     pub permission: MemberPermission,
     /// The user's last seen message `cid` in the room.
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "utoipa", schema(nullable = false))]
     pub last_seen_cid: Option<Id>,
 }
 
 /// A server-to-client event.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(rename_all = "snake_case")]
 pub enum ServerEvent {
     /// A message from a joined room.
@@ -170,5 +200,6 @@ pub enum ServerEvent {
 
 /// A client-to-server event.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "utoipa", derive(utoipa::ToSchema))]
 #[serde(rename_all = "snake_case")]
 pub enum ClientEvent {}