feat: faster MCP browsing

src-tauri/src/api_server.rs

@@ -1045,6 +1045,8 @@ impl ApiServer {
       .port();
 
     let v1_routes = build_v1_router();
+    #[cfg(feature = "e2e")]
+    let v1_routes = v1_routes.route("/v1/e2e/mcp", axum::routing::post(e2e_mcp_message));
 
     let api = ApiDoc::openapi();
 
@@ -1101,6 +1103,29 @@ impl ApiServer {
   }
 }
 
+/// The suites' way into the MCP tool engine, which the app otherwise serves
+/// only over the remote bridge. Built into E2E builds only, never published.
+#[cfg(feature = "e2e")]
+async fn e2e_mcp_message(headers: HeaderMap, body: axum::body::Bytes) -> Response {
+  use crate::mcp_server::{McpOutcome, McpServer};
+  let session = headers
+    .get("mcp-session-id")
+    .and_then(|value| value.to_str().ok());
+  match McpServer::instance()
+    .handle_message_with(session, &body, None)
+    .await
+  {
+    McpOutcome::Body {
+      body,
+      new_session_id,
+    } => Json(serde_json::json!({ "session_id": new_session_id, "body": body })).into_response(),
+    McpOutcome::Accepted => StatusCode::ACCEPTED.into_response(),
+    McpOutcome::UnknownSession => StatusCode::NOT_FOUND.into_response(),
+    McpOutcome::BadRequest => StatusCode::BAD_REQUEST.into_response(),
+    McpOutcome::RateLimited { .. } => StatusCode::TOO_MANY_REQUESTS.into_response(),
+  }
+}
+
 /// Register every `/v1` handler.
 ///
 /// Pulled out of `start` so a test can build it. Axum panics when two handlers

src-tauri/src/mcp_toolsets.rs

@@ -37,6 +37,10 @@ pub const TOOLSETS: &[(&str, &[&str])] = &[
       "batch_run_profiles",
       "batch_stop_profiles",
       "navigate",
+      "go_back",
+      "scroll",
+      "press_key",
+      "wait_for",
       "screenshot",
       "evaluate_javascript",
       "click_element",

src-tauri/src/navigation_watch.rs

@@ -67,6 +67,9 @@ impl NavigationWatch {
     };
     if method == "Page.loadEventFired" {
       self.loaded = true;
+    } else if method == "Page.frameNavigated" && restored_from_cache(params) {
+      // A page the back-forward cache keeps comes back whole: no load event.
+      self.loaded = true;
     } else if method == "Page.navigatedWithinDocument" && in_main_frame() {
       self.same_document = true;
     } else if STARTED.contains(&method) && in_main_frame() {
@@ -98,6 +101,15 @@ impl NavigationWatch {
   }
 }
 
+/// Whether a `Page.frameNavigated` brought back the top frame from the
+/// back-forward cache.
+fn restored_from_cache(params: Option<&Value>) -> bool {
+  params.is_some_and(|p| {
+    p.get("type").and_then(Value::as_str) == Some("BackForwardCacheRestore")
+      && p.pointer("/frame/parentId").is_none()
+  })
+}
+
 /// The top frame's id, from a `Page.getFrameTree` reply.
 pub fn main_frame_of(tree: &Value) -> Option<String> {
   tree
@@ -130,6 +142,34 @@ mod tests {
     assert!(!watch.navigated());
   }
 
+  #[test]
+  fn a_page_back_from_the_cache_ends_the_wait_without_a_load_event() {
+    let start = Instant::now();
+    let mut watch = NavigationWatch::new(Some("main".to_string()), true);
+    watch.on_reply(start);
+    watch.on_event(
+      "Page.frameNavigated",
+      Some(
+        &json!({ "frame": { "id": "ad", "parentId": "main" }, "type": "BackForwardCacheRestore" }),
+      ),
+    );
+    assert!(!watch.done(start), "a child frame is not the page");
+    watch.on_event(
+      "Page.frameNavigated",
+      Some(&json!({ "frame": { "id": "main" }, "type": "Navigation" })),
+    );
+    assert!(
+      !watch.done(start),
+      "a normal navigation still waits for its load"
+    );
+    watch.on_event(
+      "Page.frameNavigated",
+      Some(&json!({ "frame": { "id": "main" }, "type": "BackForwardCacheRestore" })),
+    );
+    assert!(watch.done(start));
+    assert!(watch.navigated());
+  }
+
   #[test]
   fn a_started_navigation_waits_for_its_load() {
     let start = Instant::now();