5 files changed, 66 insertions, 0 deletions
diff --git a/src/api/schema.rs b/src/api/schema.rs
index c3349c04..a404d56c 100644
--- a/src/api/schema.rs
+++ b/src/api/schema.rs
@@ -8,6 +8,7 @@ pub mod panes;
 pub mod plugins;
 pub mod response;
 pub mod server;
+pub mod session;
 pub mod tabs;
 pub mod workspaces;
 pub mod worktrees;
@@ -20,6 +21,7 @@ pub use panes::*;
 pub use plugins::*;
 pub use response::*;
 pub use server::*;
+pub use session::*;
 pub use tabs::*;
 pub use workspaces::*;
 pub use worktrees::*;
@@ -59,6 +61,8 @@ pub enum Method {
     ClientWindowTitleSet(ClientWindowTitleSetParams),
     #[serde(rename = "client.window_title.clear")]
     ClientWindowTitleClear(EmptyParams),
+    #[serde(rename = "session.snapshot")]
+    SessionSnapshot(EmptyParams),
     #[serde(rename = "workspace.create")]
     WorkspaceCreate(WorkspaceCreateParams),
     #[serde(rename = "workspace.list")]
diff --git a/src/api/schema/response.rs b/src/api/schema/response.rs
index 57ab215b..8ad41ec4 100644
--- a/src/api/schema/response.rs
+++ b/src/api/schema/response.rs
@@ -16,6 +16,7 @@ use super::plugins::{
     PluginPaneInfo,
 };
 use super::server::ServerCapabilities;
+use super::session::SessionSnapshot;
 use super::tabs::TabInfo;
 use super::workspaces::WorkspaceInfo;
 use super::worktrees::{WorktreeInfo, WorktreeSourceInfo};
@@ -47,6 +48,9 @@ pub enum ResponseResult {
         #[serde(default)]
         capabilities: Option<ServerCapabilities>,
     },
+    SessionSnapshot {
+        snapshot: Box<SessionSnapshot>,
+    },
     WorkspaceInfo {
         workspace: WorkspaceInfo,
     },
diff --git a/src/api/schema/session.rs b/src/api/schema/session.rs
new file mode 100644
index 00000000..b51f6969
--- /dev/null
+++ b/src/api/schema/session.rs
@@ -0,0 +1,23 @@
+use serde::{Deserialize, Serialize};
+
+use super::agents::AgentInfo;
+use super::panes::{PaneInfo, PaneLayoutSnapshot};
+use super::tabs::TabInfo;
+use super::workspaces::WorkspaceInfo;
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct SessionSnapshot {
+    pub version: String,
+    pub protocol: u32,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub focused_workspace_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub focused_tab_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub focused_pane_id: Option<String>,
+    pub workspaces: Vec<WorkspaceInfo>,
+    pub tabs: Vec<TabInfo>,
+    pub panes: Vec<PaneInfo>,
+    pub layouts: Vec<PaneLayoutSnapshot>,
+    pub agents: Vec<AgentInfo>,
+}
diff --git a/src/api/schema/tests.rs b/src/api/schema/tests.rs
index dd2004cf..5d61e972 100644
--- a/src/api/schema/tests.rs
+++ b/src/api/schema/tests.rs
@@ -377,6 +377,40 @@ fn success_response_round_trips() {
 }
 
 #[test]
+fn session_snapshot_request_and_response_round_trip() {
+    let request = Request {
+        id: "req_snapshot".into(),
+        method: Method::SessionSnapshot(EmptyParams::default()),
+    };
+    let json = serde_json::to_string(&request).unwrap();
+    assert!(json.contains("\"method\":\"session.snapshot\""));
+    let restored: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(restored, request);
+
+    let response = SuccessResponse {
+        id: "req_snapshot".into(),
+        result: ResponseResult::SessionSnapshot {
+            snapshot: Box::new(SessionSnapshot {
+                version: "0.1.2".into(),
+                protocol: 15,
+                focused_workspace_id: None,
+                focused_tab_id: None,
+                focused_pane_id: None,
+                workspaces: Vec::new(),
+                tabs: Vec::new(),
+                panes: Vec::new(),
+                layouts: Vec::new(),
+                agents: Vec::new(),
+            }),
+        },
+    };
+    let json = serde_json::to_string(&response).unwrap();
+    assert!(json.contains("\"type\":\"session_snapshot\""));
+    let restored: SuccessResponse = serde_json::from_str(&json).unwrap();
+    assert_eq!(restored, response);
+}
+
+#[test]
 fn worktree_request_and_response_round_trip() {
     let request = Request {
         id: "req_worktree".into(),
diff --git a/src/api/server.rs b/src/api/server.rs
index 039ede12..d01f4199 100644
--- a/src/api/server.rs
+++ b/src/api/server.rs
@@ -281,6 +281,7 @@ fn api_method_name(method: &Method) -> &'static str {
         Method::NotificationShow(_) => "notification.show",
         Method::ClientWindowTitleSet(_) => "client.window_title.set",
         Method::ClientWindowTitleClear(_) => "client.window_title.clear",
+        Method::SessionSnapshot(_) => "session.snapshot",
         Method::WorkspaceCreate(_) => "workspace.create",
         Method::WorkspaceList(_) => "workspace.list",
         Method::WorkspaceGet(_) => "workspace.get",