Added new auth-related methods and events to mcp server (#2496)

This PR adds the following:
* A getAuthStatus method on the mcp server. This returns the auth method
currently in use (chatgpt or apikey) or none if the user is not
authenticated. It also returns the "preferred auth method" which
reflects the `preferred_auth_method` value in the config.
* A logout method on the mcp server. If called, it logs out the user and
deletes the `auth.json` file — the same behavior in the cli's `/logout`
command.
* An `authStatusChange` event notification that is sent when the auth
status changes due to successful login or logout operations.
* Logic to pass command-line config overrides to the mcp server at
startup time. This allows use cases like `codex mcp -c
preferred_auth_method=apikey`.

codex-rs/protocol/src/mcp_protocol.rs

@@ -13,6 +13,7 @@ use crate::protocol::TurnAbortReason;
 use mcp_types::RequestId;
 use serde::Deserialize;
 use serde::Serialize;
+use strum_macros::Display;
 use ts_rs::TS;
 use uuid::Uuid;
 
@@ -36,6 +37,13 @@ impl GitSha {
     }
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, TS)]
+#[serde(rename_all = "lowercase")]
+pub enum AuthMode {
+    ApiKey,
+    ChatGPT,
+}
+
 /// Request from the client to the server.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
 #[serde(tag = "method", rename_all = "camelCase")]
@@ -79,6 +87,14 @@ pub enum ClientRequest {
         request_id: RequestId,
         params: CancelLoginChatGptParams,
     },
+    LogoutChatGpt {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+    },
+    GetAuthStatus {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+    },
     GitDiffToRemote {
         #[serde(rename = "id")]
         request_id: RequestId,
@@ -161,18 +177,6 @@ pub struct GitDiffToRemoteResponse {
     pub diff: String,
 }
 
-// Event name for notifying client of login completion or failure.
-pub const LOGIN_CHATGPT_COMPLETE_EVENT: &str = "codex/event/login_chatgpt_complete";
-
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
-#[serde(rename_all = "camelCase")]
-pub struct LoginChatGptCompleteNotification {
-    pub login_id: Uuid,
-    pub success: bool,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub error: Option<String>,
-}
-
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
 #[serde(rename_all = "camelCase")]
 pub struct CancelLoginChatGptParams {
@@ -189,6 +193,30 @@ pub struct GitDiffToRemoteParams {
 #[serde(rename_all = "camelCase")]
 pub struct CancelLoginChatGptResponse {}
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct LogoutChatGptParams {
+    pub login_id: Uuid,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct LogoutChatGptResponse {}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct GetAuthStatusParams {
+    pub login_id: Uuid,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct GetAuthStatusResponse {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub auth_method: Option<AuthMode>,
+    pub preferred_auth_method: AuthMode,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
 #[serde(rename_all = "camelCase")]
 pub struct SendUserMessageParams {
@@ -321,6 +349,34 @@ pub struct ApplyPatchApprovalResponse {
     pub decision: ReviewDecision,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct LoginChatGptCompleteNotification {
+    pub login_id: Uuid,
+    pub success: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct AuthStatusChangeNotification {
+    /// Current authentication method; omitted if signed out.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub auth_method: Option<AuthMode>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS, Display)]
+#[serde(tag = "type", content = "data", rename_all = "snake_case")]
+#[strum(serialize_all = "snake_case")]
+pub enum ServerNotification {
+    /// Authentication status changed
+    AuthStatusChange(AuthStatusChangeNotification),
+
+    /// ChatGPT login flow completed
+    LoginChatGptComplete(LoginChatGptCompleteNotification),
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;