Merge pull request #2049 from lightpanda-io/refactor/getNodeDetails-param-order

SemanticTree: reorder getNodeDetails params

src/Notification.zig

@@ -74,6 +74,8 @@ const EventListeners = struct {
     page_network_idle: List = .{},
     page_network_almost_idle: List = .{},
     page_frame_created: List = .{},
+    page_dom_content_loaded: List = .{},
+    page_loaded: List = .{},
     http_request_fail: List = .{},
     http_request_start: List = .{},
     http_request_intercept: List = .{},
@@ -91,6 +93,8 @@ const Events = union(enum) {
     page_network_idle: *const PageNetworkIdle,
     page_network_almost_idle: *const PageNetworkAlmostIdle,
     page_frame_created: *const PageFrameCreated,
+    page_dom_content_loaded: *const PageDOMContentLoaded,
+    page_loaded: *const PageLoaded,
     http_request_fail: *const RequestFail,
     http_request_start: *const RequestStart,
     http_request_intercept: *const RequestIntercept,
@@ -137,6 +141,18 @@ pub const PageFrameCreated = struct {
     timestamp: u64,
 };
 
+pub const PageDOMContentLoaded = struct {
+    req_id: u32,
+    frame_id: u32,
+    timestamp: u64,
+};
+
+pub const PageLoaded = struct {
+    req_id: u32,
+    frame_id: u32,
+    timestamp: u64,
+};
+
 pub const RequestStart = struct {
     transfer: *Transfer,
 };

src/SemanticTree.zig

@@ -95,9 +95,11 @@ const NodeData = struct {
     name: ?[]const u8,
     value: ?[]const u8,
     options: ?[]OptionData = null,
+    checked: ?bool = null,
     xpath: []const u8,
-    is_interactive: bool,
-    node_name: []const u8,
+    interactive: bool,
+    disabled: bool,
+    tag_name: []const u8,
 };
 
 const WalkContext = struct {
@@ -148,16 +150,21 @@ 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";
+    var checked: ?bool = null;
+    var tag_name: []const u8 = "text";
 
     if (node.is(Element)) |el| {
-        node_name = el.getTagNameLower();
+        tag_name = el.getTagNameLower();
 
         if (el.is(Element.Html.Input)) |input| {
             value = input.getValue();
-            if (el.getAttributeSafe(comptime lp.String.wrap("list"))) |list_id| {
+            if (input._input_type == .checkbox or input._input_type == .radio) {
+                checked = input.getChecked();
+            }
+            if (el.getAttributeSafe(comptime .wrap("list"))) |list_id| {
                 options = try extractDataListOptions(list_id, self.page, self.arena);
             }
         } else if (el.is(Element.Html.TextArea)) |textarea| {
@@ -172,8 +179,10 @@ fn walk(
                 is_interactive = true;
             }
         }
+
+        is_disabled = el.isDisabled();
     } else if (node._type == .document or node._type == .document_fragment) {
-        node_name = "root";
+        tag_name = "root";
     }
 
     const initial_xpath_len = ctx.xpath_buffer.items.len;
@@ -234,9 +243,11 @@ fn walk(
         .name = name,
         .value = value,
         .options = options,
+        .checked = checked,
         .xpath = xpath,
-        .is_interactive = is_interactive,
-        .node_name = node_name,
+        .interactive = is_interactive,
+        .disabled = is_disabled,
+        .tag_name = tag_name,
     };
 
     if (should_visit) {
@@ -335,7 +346,7 @@ const JsonVisitor = struct {
         try self.jw.write(data.id);
 
         try self.jw.objectField("nodeName");
-        try self.jw.write(data.node_name);
+        try self.jw.write(data.tag_name);
 
         try self.jw.objectField("xpath");
         try self.jw.write(data.xpath);
@@ -345,7 +356,12 @@ const JsonVisitor = struct {
             try self.jw.write(1);
 
             try self.jw.objectField("isInteractive");
-            try self.jw.write(data.is_interactive);
+            try self.jw.write(data.interactive);
+
+            if (data.disabled) {
+                try self.jw.objectField("isDisabled");
+                try self.jw.write(true);
+            }
 
             try self.jw.objectField("role");
             try self.jw.write(data.role);
@@ -373,6 +389,11 @@ const JsonVisitor = struct {
                 try self.jw.endObject();
             }
 
+            if (data.checked) |checked| {
+                try self.jw.objectField("checked");
+                try self.jw.write(checked);
+            }
+
             if (data.options) |options| {
                 try self.jw.objectField("options");
                 try self.jw.beginArray();
@@ -459,6 +480,9 @@ 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.interactive) {
+            try self.writer.writeAll(if (data.disabled) " [i:disabled]" else " [i]");
+        }
         if (!is_text_only) {
             try self.writer.print(" {s}", .{data.role});
         }
@@ -472,6 +496,14 @@ const TextVisitor = struct {
             }
         }
 
+        if (data.checked) |c| {
+            if (c) {
+                try self.writer.writeAll(" [checked]");
+            } else {
+                try self.writer.writeAll(" [unchecked]");
+            }
+        }
+
         if (data.options) |options| {
             try self.writer.writeAll(" options=[");
             for (options, 0..) |opt, i| {
@@ -509,6 +541,182 @@ const TextVisitor = struct {
     }
 };
 
+pub const NodeDetails = struct {
+    backendNodeId: CDPNode.Id,
+    tag_name: []const u8,
+    role: []const u8,
+    name: ?[]const u8,
+    interactive: bool,
+    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.interactive);
+
+        if (self.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(
+    arena: std.mem.Allocator,
+    node: *Node,
+    registry: *CDPNode.Registry,
+    page: *Page,
+) !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 = 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 .wrap("id"));
+        class_attr = el.getAttributeSafe(comptime .wrap("class"));
+        placeholder = el.getAttributeSafe(comptime .wrap("placeholder"));
+
+        if (el.getAttributeSafe(comptime .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 .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 = true;
+            }
+        }
+    }
+
+    return .{
+        .backendNodeId = cdp_node.id,
+        .tag_name = tag_name,
+        .role = role,
+        .name = name,
+        .interactive = is_interactive,
+        .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/browser/HttpClient.zig

@@ -1348,15 +1348,15 @@ pub const Transfer = struct {
             }
         }
 
+        transfer.req.notification.dispatch(.http_response_header_done, &.{
+            .transfer = transfer,
+        });
+
         const proceed = transfer.req.header_callback(transfer) catch |err| {
             log.err(.http, "header_callback", .{ .err = err, .req = transfer });
             return err;
         };
 
-        transfer.req.notification.dispatch(.http_response_header_done, &.{
-            .transfer = transfer,
-        });
-
         return proceed and transfer.aborted == false;
     }
 

src/browser/Page.zig

@@ -487,7 +487,6 @@ pub fn navigate(self: *Page, request_url: [:0]const u8, opts: NavigateOpts) !voi
                 return error.InjectBlankFailed;
             };
         }
-        self.documentIsComplete();
 
         session.notification.dispatch(.page_navigate, &.{
             .frame_id = self._frame_id,
@@ -519,6 +518,8 @@ pub fn navigate(self: *Page, request_url: [:0]const u8, opts: NavigateOpts) !voi
 
         // force next request id manually b/c we won't create a real req.
         _ = session.browser.http_client.incrReqId();
+
+        self.documentIsComplete();
         return;
     }
 
@@ -738,6 +739,12 @@ pub fn _documentIsLoaded(self: *Page) !void {
         self.document.asEventTarget(),
         event,
     );
+
+    self._session.notification.dispatch(.page_dom_content_loaded, &.{
+        .frame_id = self._frame_id,
+        .req_id = self._req_id,
+        .timestamp = timestamp(.monotonic),
+    });
 }
 
 pub fn scriptsCompletedLoading(self: *Page) void {
@@ -796,19 +803,6 @@ pub fn documentIsComplete(self: *Page) void {
     self._documentIsComplete() catch |err| {
         log.err(.page, "document is complete", .{ .err = err, .type = self._type, .url = self.url });
     };
-
-    if (self._navigated_options) |no| {
-        // _navigated_options will be null in special short-circuit cases, like
-        // "navigating" to about:blank, in which case this notification has
-        // already been sent
-        self._session.notification.dispatch(.page_navigated, &.{
-            .frame_id = self._frame_id,
-            .req_id = self._req_id,
-            .opts = no,
-            .url = self.url,
-            .timestamp = timestamp(.monotonic),
-        });
-    }
 }
 
 fn _documentIsComplete(self: *Page) !void {
@@ -827,6 +821,12 @@ fn _documentIsComplete(self: *Page) !void {
         try self._event_manager.dispatchDirect(window_target, event, self.window._on_load, .{ .inject_target = false, .context = "page load" });
     }
 
+    self._session.notification.dispatch(.page_loaded, &.{
+        .frame_id = self._frame_id,
+        .req_id = self._req_id,
+        .timestamp = timestamp(.monotonic),
+    });
+
     if (self._event_manager.hasDirectListeners(window_target, "pageshow", self.window._on_pageshow)) {
         const pageshow_event = (try PageTransitionEvent.initTrusted(comptime .wrap("pageshow"), .{}, self)).asEvent();
         try self._event_manager.dispatchDirect(window_target, pageshow_event, self.window._on_pageshow, .{ .context = "page show" });
@@ -879,6 +879,19 @@ fn pageHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
         });
     }
 
+    if (self._navigated_options) |no| {
+        // _navigated_options will be null in special short-circuit cases, like
+        // "navigating" to about:blank, in which case this notification has
+        // already been sent
+        self._session.notification.dispatch(.page_navigated, &.{
+            .frame_id = self._frame_id,
+            .req_id = self._req_id,
+            .opts = no,
+            .url = self.url,
+            .timestamp = timestamp(.monotonic),
+        });
+    }
+
     return true;
 }
 

src/cdp/CDP.zig

@@ -432,6 +432,8 @@ pub fn BrowserContext(comptime CDP_T: type) type {
             try notification.register(.page_navigate, self, onPageNavigate);
             try notification.register(.page_navigated, self, onPageNavigated);
             try notification.register(.page_frame_created, self, onPageFrameCreated);
+            try notification.register(.page_dom_content_loaded, self, onPageDOMContentLoaded);
+            try notification.register(.page_loaded, self, onPageLoaded);
         }
 
         pub fn deinit(self: *Self) void {
@@ -607,6 +609,16 @@ pub fn BrowserContext(comptime CDP_T: type) type {
             return @import("domains/page.zig").pageFrameCreated(self, msg);
         }
 
+        pub fn onPageDOMContentLoaded(ctx: *anyopaque, msg: *const Notification.PageDOMContentLoaded) !void {
+            const self: *Self = @ptrCast(@alignCast(ctx));
+            return @import("domains/page.zig").pageDOMContentLoaded(self, msg);
+        }
+
+        pub fn onPageLoaded(ctx: *anyopaque, msg: *const Notification.PageLoaded) !void {
+            const self: *Self = @ptrCast(@alignCast(ctx));
+            return @import("domains/page.zig").pageLoaded(self, msg);
+        }
+
         pub fn onPageNetworkIdle(ctx: *anyopaque, msg: *const Notification.PageNetworkIdle) !void {
             const self: *Self = @ptrCast(@alignCast(ctx));
             return @import("domains/page.zig").pageNetworkIdle(self, msg);

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(cmd.arena, node, &bc.node_registry, page) 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/cdp/domains/page.zig

@@ -420,7 +420,6 @@ pub fn pageNavigated(arena: Allocator, bc: anytype, event: *const Notification.P
     // things, but no session.
     const session_id = bc.session_id orelse return;
 
-    const timestamp = event.timestamp;
     const frame_id = &id.toFrameId(event.frame_id);
     const loader_id = &id.toLoaderId(event.req_id);
 
@@ -472,9 +471,9 @@ pub fn pageNavigated(arena: Allocator, bc: anytype, event: *const Notification.P
     const page = bc.session.currentPage() orelse return error.PageNotLoaded;
 
     // When we actually recreated the context we should have the inspector send
-    // this event, see: resetContextGroup Sending this event will tell the
-    // client that the context ids they had are invalid and the context shouls
-    // be dropped The client will expect us to send new contextCreated events,
+    // this event, see: resetContextGroup. Sending this event will tell the
+    // client that the context ids they had are invalid and the context should
+    // be dropped. The client will expect us to send new contextCreated events,
     // such that the client has new id's for the active contexts.
     // Only send executionContextsCleared for main frame navigations. For child
     // frames (iframes), clearing all contexts would destroy the main frame's
@@ -484,6 +483,18 @@ pub fn pageNavigated(arena: Allocator, bc: anytype, event: *const Notification.P
         try cdp.sendEvent("Runtime.executionContextsCleared", null, .{ .session_id = session_id });
     }
 
+    // frameNavigated event
+    try cdp.sendEvent("Page.frameNavigated", .{
+        .type = "Navigation",
+        .frame = Frame{
+            .id = frame_id,
+            .url = event.url,
+            .loaderId = loader_id,
+            .securityOrigin = bc.security_origin,
+            .secureContextType = bc.secure_context_type,
+        },
+    }, .{ .session_id = session_id });
+
     {
         const aux_data = try std.fmt.allocPrint(arena, "{{\"isDefault\":true,\"type\":\"default\",\"frameId\":\"{s}\",\"loaderId\":\"{s}\"}}", .{ frame_id, loader_id });
 
@@ -554,18 +565,22 @@ pub fn pageNavigated(arena: Allocator, bc: anytype, event: *const Notification.P
     // chromedp client expects to receive the events is this order.
     // see https://github.com/chromedp/chromedp/issues/1558
     try cdp.sendEvent("DOM.documentUpdated", null, .{ .session_id = session_id });
+}
+
+pub fn pageDOMContentLoaded(bc: anytype, event: *const Notification.PageDOMContentLoaded) !void {
+    const session_id = bc.session_id orelse return;
+    const timestamp = event.timestamp;
+    var cdp = bc.cdp;
 
-    // domContentEventFired event
-    // TODO: partially hard coded
     try cdp.sendEvent(
         "Page.domContentEventFired",
         .{ .timestamp = timestamp },
         .{ .session_id = session_id },
     );
 
-    // lifecycle DOMContentLoaded event
-    // TODO: partially hard coded
     if (bc.page_life_cycle_events) {
+        const frame_id = &id.toFrameId(event.frame_id);
+        const loader_id = &id.toLoaderId(event.req_id);
         try cdp.sendEvent("Page.lifecycleEvent", LifecycleEvent{
             .timestamp = timestamp,
             .name = "DOMContentLoaded",
@@ -573,16 +588,23 @@ pub fn pageNavigated(arena: Allocator, bc: anytype, event: *const Notification.P
             .loaderId = loader_id,
         }, .{ .session_id = session_id });
     }
+}
+
+pub fn pageLoaded(bc: anytype, event: *const Notification.PageLoaded) !void {
+    const session_id = bc.session_id orelse return;
+    const timestamp = event.timestamp;
+    var cdp = bc.cdp;
+
+    const frame_id = &id.toFrameId(event.frame_id);
 
-    // loadEventFired event
     try cdp.sendEvent(
         "Page.loadEventFired",
         .{ .timestamp = timestamp },
         .{ .session_id = session_id },
     );
 
-    // lifecycle DOMContentLoaded event
     if (bc.page_life_cycle_events) {
+        const loader_id = &id.toLoaderId(event.req_id);
         try cdp.sendEvent("Page.lifecycleEvent", LifecycleEvent{
             .timestamp = timestamp,
             .name = "load",
@@ -591,7 +613,6 @@ pub fn pageNavigated(arena: Allocator, bc: anytype, event: *const Notification.P
         }, .{ .session_id = session_id });
     }
 
-    // frameStoppedLoading
     return cdp.sendEvent("Page.frameStoppedLoading", .{
         .frameId = frame_id,
     }, .{ .session_id = session_id });

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(arena, node.dom, &server.node_registry, page) 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);