SemanticTree: Add nodeDetails tool

Adds a tool to retrieve detailed node metadata and updates the
semantic tree to track and display the disabled state of elements.

src/SemanticTree.zig

@@ -97,6 +97,7 @@ const NodeData = struct {
     options: ?[]OptionData = null,
     xpath: []const u8,
     is_interactive: bool,
+    is_disabled: bool,
     node_name: []const u8,
 };
 
@@ -148,6 +149,7 @@ fn walk(
     const role = try axn.getRole();
 
     var is_interactive = false;
+    var is_disabled = false;
     var value: ?[]const u8 = null;
     var options: ?[]OptionData = null;
     var node_name: []const u8 = "text";
@@ -172,6 +174,8 @@ fn walk(
                 is_interactive = true;
             }
         }
+
+        is_disabled = el.isDisabled();
     } else if (node._type == .document or node._type == .document_fragment) {
         node_name = "root";
     }
@@ -236,6 +240,7 @@ fn walk(
         .options = options,
         .xpath = xpath,
         .is_interactive = is_interactive,
+        .is_disabled = is_disabled,
         .node_name = node_name,
     };
 
@@ -347,6 +352,11 @@ const JsonVisitor = struct {
             try self.jw.objectField("isInteractive");
             try self.jw.write(data.is_interactive);
 
+            if (data.is_disabled) {
+                try self.jw.objectField("isDisabled");
+                try self.jw.write(true);
+            }
+
             try self.jw.objectField("role");
             try self.jw.write(data.role);
 
@@ -459,6 +469,9 @@ const TextVisitor = struct {
         const is_text_only = std.mem.eql(u8, data.role, "StaticText") or std.mem.eql(u8, data.role, "none") or std.mem.eql(u8, data.role, "generic");
 
         try self.writer.print("{d}", .{data.id});
+        if (data.is_interactive) {
+            try self.writer.writeAll(if (data.is_disabled) " [i:disabled]" else " [i]");
+        }
         if (!is_text_only) {
             try self.writer.print(" {s}", .{data.role});
         }
@@ -509,6 +522,177 @@ const TextVisitor = struct {
     }
 };
 
+pub const NodeDetails = struct {
+    backendNodeId: CDPNode.Id,
+    tag_name: []const u8,
+    role: []const u8,
+    name: ?[]const u8,
+    is_interactive: bool,
+    is_disabled: bool,
+    value: ?[]const u8 = null,
+    input_type: ?[]const u8 = null,
+    placeholder: ?[]const u8 = null,
+    href: ?[]const u8 = null,
+    id: ?[]const u8 = null,
+    class: ?[]const u8 = null,
+    checked: ?bool = null,
+    options: ?[]OptionData = null,
+
+    pub fn jsonStringify(self: *const NodeDetails, jw: anytype) !void {
+        try jw.beginObject();
+
+        try jw.objectField("backendNodeId");
+        try jw.write(self.backendNodeId);
+
+        try jw.objectField("tagName");
+        try jw.write(self.tag_name);
+
+        try jw.objectField("role");
+        try jw.write(self.role);
+
+        if (self.name) |n| {
+            try jw.objectField("name");
+            try jw.write(n);
+        }
+
+        try jw.objectField("isInteractive");
+        try jw.write(self.is_interactive);
+
+        if (self.is_disabled) {
+            try jw.objectField("isDisabled");
+            try jw.write(true);
+        }
+
+        if (self.value) |v| {
+            try jw.objectField("value");
+            try jw.write(v);
+        }
+
+        if (self.input_type) |v| {
+            try jw.objectField("inputType");
+            try jw.write(v);
+        }
+
+        if (self.placeholder) |v| {
+            try jw.objectField("placeholder");
+            try jw.write(v);
+        }
+
+        if (self.href) |v| {
+            try jw.objectField("href");
+            try jw.write(v);
+        }
+
+        if (self.id) |v| {
+            try jw.objectField("id");
+            try jw.write(v);
+        }
+
+        if (self.class) |v| {
+            try jw.objectField("class");
+            try jw.write(v);
+        }
+
+        if (self.checked) |c| {
+            try jw.objectField("checked");
+            try jw.write(c);
+        }
+
+        if (self.options) |opts| {
+            try jw.objectField("options");
+            try jw.beginArray();
+            for (opts) |opt| {
+                try jw.beginObject();
+                try jw.objectField("value");
+                try jw.write(opt.value);
+                try jw.objectField("text");
+                try jw.write(opt.text);
+                if (opt.selected) {
+                    try jw.objectField("selected");
+                    try jw.write(true);
+                }
+                try jw.endObject();
+            }
+            try jw.endArray();
+        }
+
+        try jw.endObject();
+    }
+};
+
+pub fn getNodeDetails(node: *Node, registry: *CDPNode.Registry, page: *Page, arena: std.mem.Allocator) !NodeDetails {
+    const cdp_node = try registry.register(node);
+    const axn = AXNode.fromNode(node);
+    const role = try axn.getRole();
+    const name = try axn.getName(page, arena);
+
+    var is_interactive_val = false;
+    var is_disabled = false;
+    var tag_name: []const u8 = "text";
+    var value: ?[]const u8 = null;
+    var input_type: ?[]const u8 = null;
+    var placeholder: ?[]const u8 = null;
+    var href: ?[]const u8 = null;
+    var id_attr: ?[]const u8 = null;
+    var class_attr: ?[]const u8 = null;
+    var checked: ?bool = null;
+    var options: ?[]OptionData = null;
+
+    if (node.is(Element)) |el| {
+        tag_name = el.getTagNameLower();
+        is_disabled = el.isDisabled();
+        id_attr = el.getAttributeSafe(comptime lp.String.wrap("id"));
+        class_attr = el.getAttributeSafe(comptime lp.String.wrap("class"));
+        placeholder = el.getAttributeSafe(comptime lp.String.wrap("placeholder"));
+
+        if (el.getAttributeSafe(comptime lp.String.wrap("href"))) |h| {
+            const URL = lp.URL;
+            href = URL.resolve(arena, page.base(), h, .{ .encode = true }) catch h;
+        }
+
+        if (el.is(Element.Html.Input)) |input| {
+            value = input.getValue();
+            input_type = input._input_type.toString();
+            if (input._input_type == .checkbox or input._input_type == .radio) {
+                checked = input.getChecked();
+            }
+            if (el.getAttributeSafe(comptime lp.String.wrap("list"))) |list_id| {
+                options = try extractDataListOptions(list_id, page, arena);
+            }
+        } else if (el.is(Element.Html.TextArea)) |textarea| {
+            value = textarea.getValue();
+        } else if (el.is(Element.Html.Select)) |select| {
+            value = select.getValue(page);
+            options = try extractSelectOptions(el.asNode(), page, arena);
+        }
+
+        if (el.is(Element.Html)) |html_el| {
+            const listener_targets = try interactive.buildListenerTargetMap(page, arena);
+            var pointer_events_cache: Element.PointerEventsCache = .empty;
+            if (interactive.classifyInteractivity(page, el, html_el, listener_targets, &pointer_events_cache) != null) {
+                is_interactive_val = true;
+            }
+        }
+    }
+
+    return .{
+        .backendNodeId = cdp_node.id,
+        .tag_name = tag_name,
+        .role = role,
+        .name = name,
+        .is_interactive = is_interactive_val,
+        .is_disabled = is_disabled,
+        .value = value,
+        .input_type = input_type,
+        .placeholder = placeholder,
+        .href = href,
+        .id = id_attr,
+        .class = class_attr,
+        .checked = checked,
+        .options = options,
+    };
+}
+
 const testing = @import("testing.zig");
 
 test "SemanticTree backendDOMNodeId" {

src/cdp/domains/lp.zig

@@ -30,6 +30,7 @@ pub fn processMessage(cmd: anytype) !void {
         getMarkdown,
         getSemanticTree,
         getInteractiveElements,
+        getNodeDetails,
         getStructuredData,
         detectForms,
         clickNode,
@@ -42,6 +43,7 @@ pub fn processMessage(cmd: anytype) !void {
         .getMarkdown => return getMarkdown(cmd),
         .getSemanticTree => return getSemanticTree(cmd),
         .getInteractiveElements => return getInteractiveElements(cmd),
+        .getNodeDetails => return getNodeDetails(cmd),
         .getStructuredData => return getStructuredData(cmd),
         .detectForms => return detectForms(cmd),
         .clickNode => return clickNode(cmd),
@@ -141,6 +143,24 @@ fn getInteractiveElements(cmd: anytype) !void {
     }, .{});
 }
 
+fn getNodeDetails(cmd: anytype) !void {
+    const Params = struct {
+        backendNodeId: Node.Id,
+    };
+    const params = (try cmd.params(Params)) orelse return error.InvalidParam;
+
+    const bc = cmd.browser_context orelse return error.NoBrowserContext;
+    const page = bc.session.currentPage() orelse return error.PageNotLoaded;
+
+    const node = (bc.node_registry.lookup_by_id.get(params.backendNodeId) orelse return error.InvalidNodeId).dom;
+
+    const details = SemanticTree.getNodeDetails(node, &bc.node_registry, page, cmd.arena) catch return error.InternalError;
+
+    return cmd.sendResult(.{
+        .nodeDetails = details,
+    }, .{});
+}
+
 fn getStructuredData(cmd: anytype) !void {
     const bc = cmd.browser_context orelse return error.NoBrowserContext;
     const page = bc.session.currentPage() orelse return error.PageNotLoaded;

src/mcp/tools.zig

@@ -75,6 +75,19 @@ pub const tool_list = [_]protocol.Tool{
             \\}
         ),
     },
+    .{
+        .name = "nodeDetails",
+        .description = "Get detailed information about a specific node by its backend node ID. Returns tag, role, name, interactivity, disabled state, value, input type, placeholder, href, checked state, and select options.",
+        .inputSchema = protocol.minify(
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "backendNodeId": { "type": "integer", "description": "The backend node ID of the element to inspect." }
+            \\  },
+            \\  "required": ["backendNodeId"]
+            \\}
+        ),
+    },
     .{
         .name = "interactiveElements",
         .description = "Extract interactive elements from the opened page. If a url is provided, it navigates to that url first.",
@@ -256,6 +269,7 @@ const ToolAction = enum {
     navigate,
     markdown,
     links,
+    nodeDetails,
     interactiveElements,
     structuredData,
     detectForms,
@@ -272,6 +286,7 @@ const tool_map = std.StaticStringMap(ToolAction).initComptime(.{
     .{ "navigate", .navigate },
     .{ "markdown", .markdown },
     .{ "links", .links },
+    .{ "nodeDetails", .nodeDetails },
     .{ "interactiveElements", .interactiveElements },
     .{ "structuredData", .structuredData },
     .{ "detectForms", .detectForms },
@@ -305,6 +320,7 @@ pub fn handleCall(server: *Server, arena: std.mem.Allocator, req: protocol.Reque
         .goto, .navigate => try handleGoto(server, arena, req.id.?, call_params.arguments),
         .markdown => try handleMarkdown(server, arena, req.id.?, call_params.arguments),
         .links => try handleLinks(server, arena, req.id.?, call_params.arguments),
+        .nodeDetails => try handleNodeDetails(server, arena, req.id.?, call_params.arguments),
         .interactiveElements => try handleInteractiveElements(server, arena, req.id.?, call_params.arguments),
         .structuredData => try handleStructuredData(server, arena, req.id.?, call_params.arguments),
         .detectForms => try handleDetectForms(server, arena, req.id.?, call_params.arguments),
@@ -373,6 +389,32 @@ fn handleSemanticTree(server: *Server, arena: std.mem.Allocator, id: std.json.Va
     };
 }
 
+fn handleNodeDetails(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
+    const Params = struct {
+        backendNodeId: CDPNode.Id,
+    };
+    const args = try parseArgs(Params, arena, arguments, server, id, "nodeDetails");
+
+    _ = server.session.currentPage() orelse {
+        return server.sendError(id, .PageNotLoaded, "Page not loaded");
+    };
+
+    const node = server.node_registry.lookup_by_id.get(args.backendNodeId) orelse {
+        return server.sendError(id, .InvalidParams, "Node not found");
+    };
+
+    const page = server.session.currentPage().?;
+    const details = lp.SemanticTree.getNodeDetails(node.dom, &server.node_registry, page, arena) catch {
+        return server.sendError(id, .InternalError, "Failed to get node details");
+    };
+
+    var aw: std.Io.Writer.Allocating = .init(arena);
+    try std.json.Stringify.value(&details, .{}, &aw.writer);
+
+    const content = [_]protocol.TextContent([]const u8){.{ .text = aw.written() }};
+    try server.sendResult(id, protocol.CallToolResult([]const u8){ .content = &content });
+}
+
 fn handleInteractiveElements(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
     const args = try parseArgsOrDefault(UrlParams, arena, arguments, server, id);
     const page = try ensurePage(server, id, args.url);