CDP/MCP: improve Stagehand compatibility for semantic tree

src/SemanticTree.zig

@@ -150,9 +150,9 @@ fn dump(self: Self, node: *Node, jw: *std.json.Stringify, parent_xpath: []const
     try jw.beginObject();
 
     try jw.objectField("nodeId");
-    try jw.write(cdp_node.id);
+    try jw.write(try std.fmt.allocPrint(self.arena, "{d}", .{cdp_node.id}));
 
-    try jw.objectField("backendNodeId");
+    try jw.objectField("backendDOMNodeId");
     try jw.write(cdp_node.id);
 
     try jw.objectField("nodeName");
@@ -171,6 +171,26 @@ fn dump(self: Self, node: *Node, jw: *std.json.Stringify, parent_xpath: []const
         try jw.objectField("role");
         try jw.write(role);
 
+        // Add accessible name (e.g. button label, aria-label, etc.)
+        if (try axn.getName(self.page, self.arena)) |name| {
+            if (name.len > 0) {
+                try jw.objectField("name");
+                try jw.write(name);
+            }
+        }
+
+        // Add value for input elements
+        if (el.is(Element.Html.Input)) |input| {
+            try jw.objectField("value");
+            try jw.write(input.getValue());
+        } else if (el.is(Element.Html.TextArea)) |textarea| {
+            try jw.objectField("value");
+            try jw.write(textarea.getValue());
+        } else if (el.is(Element.Html.Select)) |select| {
+            try jw.objectField("value");
+            try jw.write(select.getValue(self.page));
+        }
+
         if (el._attributes) |attrs| {
             try jw.objectField("attributes");
             try jw.beginObject();

src/cdp/AXNode.zig

@@ -756,6 +756,74 @@ const AXSource = enum(u8) {
     value, // input value
 };
 
+pub fn getName(self: AXNode, page: *Page, allocator: std.mem.Allocator) !?[]const u8 {
+    var aw: std.Io.Writer.Allocating = .init(allocator);
+    defer aw.deinit();
+
+    // We need to bypass the strict JSON writer used in writeName
+    // We'll create a dummy writer that just writes to our buffer
+    const DummyWriter = struct {
+        aw: *std.Io.Writer.Allocating,
+        writer: *std.Io.Writer,
+
+        pub fn write(w: @This(), val: anytype) !void {
+            const T = @TypeOf(val);
+            if (T == []const u8 or T == [:0]const u8 or T == *const [val.len]u8) {
+                try w.aw.writer.writeAll(val);
+            } else if (comptime std.meta.hasMethod(T, "format")) {
+                try std.fmt.format(w.aw.writer, "{s}", .{val});
+            } else {
+                // Ignore unexpected types to avoid garbage output
+            }
+        }
+
+        pub fn beginWriteRaw(w: @This()) !void {
+            _ = w;
+        }
+        pub fn endWriteRaw(w: @This()) void {
+            _ = w;
+        }
+        pub fn writeByte(w: @This(), b: u8) !void {
+            try w.aw.writer.writeByte(b);
+        }
+        pub fn writeAll(w: @This(), s: []const u8) !void {
+            try w.aw.writer.writeAll(s);
+        }
+
+        // Mock object methods
+        pub fn objectField(w: @This(), name: []const u8) !void {
+            _ = w;
+            _ = name;
+        }
+        pub fn beginObject(w: @This()) !void {
+            _ = w;
+        }
+        pub fn endObject(w: @This()) !void {
+            _ = w;
+        }
+        pub fn beginArray(w: @This()) !void {
+            _ = w;
+        }
+        pub fn endArray(w: @This()) !void {
+            _ = w;
+        }
+    };
+
+    const w = DummyWriter{ .aw = &aw, .writer = &aw.writer };
+
+    const source = try self.writeName(w, page);
+    if (source != null) {
+        var str = aw.written();
+        // writeString manually injects literal quotes for JSON, we need to strip them
+        if (str.len >= 2 and str[0] == '"' and str[str.len - 1] == '"') {
+            str = str[1 .. str.len - 1];
+        }
+        return try allocator.dupe(u8, str);
+    }
+
+    return null;
+}
+
 fn writeName(axnode: AXNode, w: anytype, page: *Page) !?AXSource {
     const node = axnode.dom;