Add goal mode app-server API

codex-rs/protocol/src/protocol.rs

@@ -1465,6 +1465,9 @@ pub enum EventMsg {
     /// Updated session metadata (e.g., thread name changes).
     ThreadNameUpdated(ThreadNameUpdatedEvent),
 
+    /// Updated long-running goal metadata for the thread.
+    ThreadGoalUpdated(ThreadGoalUpdatedEvent),
+
     /// Incremental MCP startup progress updates.
     McpStartupUpdate(McpStartupUpdateEvent),
 
@@ -3512,6 +3515,40 @@ pub struct ThreadNameUpdatedEvent {
     pub thread_name: Option<String>,
 }
 
+#[derive(Debug, Clone, Copy, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "protocol/")]
+pub enum ThreadGoalStatus {
+    Active,
+    Paused,
+    #[serde(alias = "budgetExceeded")]
+    BudgetStopped,
+    Complete,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "protocol/")]
+pub struct ThreadGoal {
+    pub thread_id: ThreadId,
+    pub objective: String,
+    pub status: ThreadGoalStatus,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub token_budget: Option<i64>,
+    pub tokens_used: i64,
+    pub created_at: i64,
+    pub updated_at: i64,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "protocol/")]
+pub struct ThreadGoalUpdatedEvent {
+    pub thread_id: ThreadId,
+    pub goal: ThreadGoal,
+}
+
 /// User's decision in response to an ExecApprovalRequest.
 #[derive(Debug, Default, Clone, Deserialize, Serialize, PartialEq, Eq, Display, JsonSchema, TS)]
 #[serde(rename_all = "snake_case")]
@@ -3614,6 +3651,7 @@ pub enum TurnAbortReason {
     Interrupted,
     Replaced,
     ReviewEnded,
+    BudgetExceeded,
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq, JsonSchema, TS)]