diff --git a/src/core.zig b/src/core.zig
index db6c178..17ffd7d 100644
--- a/src/core.zig
+++ b/src/core.zig
@@ -160,7 +160,7 @@ pub const ShmPool = struct {
         return .{ .conn = conn, .id = id };
     }
 
-    pub fn create_buffer(shm_pool: ShmPool, offset: i32, width: i32, height: i32, stride: i32, format: Shm.Format) u32 {
+    pub fn create_buffer(shm_pool: ShmPool, offset: i32, width: i32, height: i32, stride: i32, format: Shm.Format) !Buffer {
         const new_id = shm_pool.conn.id_pool.create();
         try shm_pool.conn.send(
             Request,
@@ -174,7 +174,7 @@ pub const ShmPool = struct {
                 .format = format,
             } },
         );
-        return Surface.init(shm_pool.conn, new_id);
+        return Buffer.init(shm_pool.conn, new_id);
     }
 };
 
@@ -216,7 +216,7 @@ pub const Shm = struct {
         return .{ .conn = conn, .id = id };
     }
 
-    pub fn create_pool(shm: *const Shm, pool_fd: u32, size: u32) ShmPool {
+    pub fn create_pool(shm: *const Shm, pool_fd: u32, size: u32) !ShmPool {
         const new_id = shm.conn.id_pool.create();
         try shm.conn.send(
             Request,
@@ -284,6 +284,31 @@ pub const Surface = struct {
         return .{ .conn = conn, .id = id };
     }
 
+    pub fn attach(surface: Surface, buffer: Buffer, x: i32, y: i32) !void {
+        try surface.conn.send(
+            Request,
+            surface.id,
+            .{ .attach = .{
+                .buffer = buffer.id,
+                .x = x,
+                .y = y,
+            } },
+        );
+    }
+
+    pub fn damage(surface: Surface, x: i32, y: i32, width: i32, height: i32) !void {
+        try surface.conn.send(
+            Request,
+            surface.id,
+            .{ .damage = .{
+                .x = x,
+                .y = y,
+                .width = width,
+                .height = height,
+            } },
+        );
+    }
+
     pub fn commit(surface: Surface) !void {
         try surface.conn.send(
             Request,
@@ -301,6 +326,13 @@ pub const Buffer = struct {
     pub const Event = union(enum) {
         release: void,
     };
+
+    conn: *Conn,
+    id: u32,
+
+    pub fn init(conn: *Conn, id: u32) Buffer {
+        return .{ .conn = conn, .id = id };
+    }
 };
 
 pub const Seat = struct {
@@ -344,6 +376,40 @@ pub const Seat = struct {
     pub fn init(conn: *Conn, id: u32) Seat {
         return .{ .conn = conn, .id = id };
     }
+
+    pub fn get_pointer(seat: Seat) !Pointer {
+        const new_id = seat.conn.id_pool.create();
+        try seat.conn.send(
+            Request,
+            seat.id,
+            .{ .get_pointer = .{
+                .new_id = new_id,
+            } },
+        );
+        return Pointer.init(seat.conn, new_id);
+    }
+    pub fn get_keyboard(seat: Seat) !Keyboard {
+        const new_id = seat.conn.id_pool.create();
+        try seat.conn.send(
+            Request,
+            seat.id,
+            .{ .get_keyboard = .{
+                .new_id = new_id,
+            } },
+        );
+        return Keyboard.init(seat.conn, new_id);
+    }
+    pub fn get_touch(seat: Seat) !Touch {
+        const new_id = seat.conn.id_pool.create();
+        try seat.conn.send(
+            Request,
+            seat.id,
+            .{ .get_touch = .{
+                .new_id = new_id,
+            } },
+        );
+        return Touch.init(seat.conn, new_id);
+    }
 };
 
 pub const Pointer = struct {
@@ -435,7 +501,7 @@ pub const Pointer = struct {
     conn: *Conn,
     id: u32,
 
-    pub fn init(conn: *Conn, id: u32) Seat {
+    pub fn init(conn: *Conn, id: u32) Pointer {
         return .{ .conn = conn, .id = id };
     }
 };
@@ -492,7 +558,7 @@ pub const Keyboard = struct {
     conn: *Conn,
     id: u32,
 
-    pub fn init(conn: *Conn, id: u32) Seat {
+    pub fn init(conn: *Conn, id: u32) Keyboard {
         return .{ .conn = conn, .id = id };
     }
 };
@@ -538,7 +604,7 @@ pub const Touch = struct {
     conn: *Conn,
     id: u32,
 
-    pub fn init(conn: *Conn, id: u32) Seat {
+    pub fn init(conn: *Conn, id: u32) Touch {
         return .{ .conn = conn, .id = id };
     }
 };
diff --git a/src/main.zig b/src/main.zig
index ccef19a..a805968 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -63,6 +63,7 @@ pub fn main() !void {
     var conn = try Conn.init(gpa, display_path);
     defer conn.deinit();
 
+    // Register all globals
     var ctx = try Context.init(&conn);
 
     const compositor = try ctx.getGlobal(wayland.core.Compositor);
@@ -75,58 +76,468 @@ pub fn main() !void {
     try surface.commit();
 
     const display = try ctx.getGlobal(wayland.core.Display);
-    const registry_done = try display.sync();
 
     const shm = try ctx.getGlobal(wayland.core.Shm);
     const seat = try ctx.getGlobal(wayland.core.Seat);
 
-    var done = false;
-    var surface_configured = false;
-    var seat_capabilties: ?wayland.core.Seat.Capability = null;
-    while (!done or !surface_configured) {
+    var app = App{
+        .conn = &conn,
+        .ctx = &ctx,
+        .ally = gpa,
+        .callbacks = std.AutoHashMap(u32, App.Callback).init(gpa),
+        .state = .{ .init = .{} },
+        .display = display,
+        .shm = shm,
+        .xdg_wmbase = xdg_wm_base,
+        .surface = surface,
+        .xdg_surface = xdg_surface,
+        .xdg_toplevel = xdg_toplevel,
+    };
+    defer app.deinit();
+
+    try app.callbacks.put(seat.id, seatInitHandler);
+    try app.callbacks.put(xdg_toplevel.id, toplevelInitHandler);
+    try app.callbacks.put(xdg_surface.id, surfaceInitHandler);
+    try app.callbacks.put(display.id, displayHandler);
+
+    while (app.state == .init) {
         const header, const body = try conn.recv();
 
-        if (header.object_id == xdg_surface.id) {
-            const event = try wayland.deserialize(wayland.xdg.Surface.Event, header, body);
-            switch (event) {
-                .configure => |conf| {
-                    try xdg_surface.ack_configure(conf.serial);
-                    surface_configured = true;
-                },
-            }
-        } else if (header.object_id == xdg_toplevel.id) {
-            const event = try wayland.deserialize(wayland.xdg.Toplevel.Event, header, body);
-            std.debug.print("<- {}\n", .{event});
-        } else if (header.object_id == registry_done) {
-            done = true;
-        } else if (header.object_id == shm.id) {
-            const event = try wayland.deserialize(wayland.core.Shm.Event, header, body);
-            switch (event) {
-                .format => |format| std.debug.print("<- format {} {}\n", .{ format.format, std.zig.fmtEscapes(std.mem.asBytes(&format.format)) }),
-            }
-        } else if (header.object_id == seat.id) {
-            const event = try wayland.deserialize(wayland.core.Seat.Event, header, body);
-            switch (event) {
-                .capabilities => |capabilities| {
-                    const cap: wayland.core.Seat.Capability = @bitCast(capabilities.capability);
-                    std.debug.print("<- wl_seat.capabilties = {}\n", .{cap});
-                    seat_capabilties = cap;
-                },
-                .name => |name| {
-                    std.debug.print("<- wl_seat.name = {s}\n", .{name.name});
-                },
-            }
-        } else if (header.object_id == display.id) {
-            const event = try wayland.deserialize(wayland.core.Display.Event, header, body);
-            switch (event) {
-                .@"error" => |err| std.debug.print("<- error({}): {} {s}\n", .{ err.object_id, err.code, err.message }),
-                .delete_id => |id| {
-                    std.debug.print("id {} deleted\n", .{id});
-                    conn.id_pool.destroy(id.id);
-                },
-            }
+        if (app.callbacks.get(header.object_id)) |callback| {
+            try callback(&app, header, body);
         } else {
-            std.debug.print("{} {x} \"{}\"\n", .{ header.object_id, header.size_and_opcode.opcode, std.zig.fmtEscapes(std.mem.sliceAsBytes(body)) });
+            const typename = if (ctx.getGlobalObjectName(header.object_id)) |name|
+                name
+            else
+                "UNKNOWN";
+            std.debug.print("{} ({s}) {x} \"{}\"\n", .{
+                header.object_id,
+                typename,
+                header.size_and_opcode.opcode,
+                std.zig.fmtEscapes(std.mem.sliceAsBytes(body)),
+            });
+        }
+    }
+
+    const pool = if (app.state == .run_mobile) &app.state.run_mobile.pool else &app.state.run_desktop.pool;
+    const width = if (app.state == .run_mobile) app.state.run_mobile.width else app.state.run_desktop.width;
+    const height = if (app.state == .run_mobile) app.state.run_mobile.height else app.state.run_desktop.height;
+
+    // render
+    const canvas = try pool.getFramebuffer(.{ width, height });
+    canvas.renderGradient();
+    try canvas.attach(surface);
+    try app.callbacks.put(canvas.buffer.id, bufferHandler);
+
+    while (app.state != .close) {
+        const header, const body = try conn.recv();
+
+        if (app.callbacks.get(header.object_id)) |callback| {
+            try callback(&app, header, body);
+        } else {
+            const typename = if (ctx.getGlobalObjectName(header.object_id)) |name|
+                name
+            else
+                "UNKNOWN";
+            std.debug.print("{} ({s}) {x} \"{}\"\n", .{
+                header.object_id,
+                typename,
+                header.size_and_opcode.opcode,
+                std.zig.fmtEscapes(std.mem.sliceAsBytes(body)),
+            });
         }
     }
 }
+
+const App = struct {
+    conn: *Conn,
+    ctx: *Context,
+    ally: std.mem.Allocator,
+    callbacks: std.AutoHashMap(u32, Callback),
+
+    display: wayland.core.Display,
+    shm: wayland.core.Shm,
+    surface: wayland.core.Surface,
+    xdg_wmbase: wayland.xdg.WmBase,
+    xdg_surface: wayland.xdg.Surface,
+    xdg_toplevel: wayland.xdg.Toplevel,
+
+    state: union(enum) {
+        init: struct {
+            toplevel_config: ?SurfaceConfiguration = null,
+            surface_configured: bool = false,
+            seat_capabilities: ?wayland.core.Seat.Capability = null,
+            pointer: ?wayland.core.Pointer = null,
+            keyboard: ?wayland.core.Keyboard = null,
+            touch: ?wayland.core.Touch = null,
+        },
+        run_mobile: struct {
+            width: u32,
+            height: u32,
+            pool: Pool,
+            touch: wayland.core.Touch,
+        },
+        run_desktop: struct {
+            width: u32,
+            height: u32,
+            pool: Pool,
+            keyboard: wayland.core.Keyboard,
+            pointer: wayland.core.Pointer,
+            mouse: struct {
+                x: f32,
+                y: f32,
+            },
+        },
+        close,
+    },
+
+    const SurfaceConfiguration = struct {
+        width: u32,
+        height: u32,
+    };
+
+    const Callback = *const fn (*App, wayland.Header, []const u32) anyerror!void;
+
+    fn deinit(app: *App) void {
+        app.callbacks.deinit();
+    }
+
+    fn checkInit(app: *App) !void {
+        std.debug.assert(app.state == .init);
+        const init = app.state.init;
+        if (!init.surface_configured) return;
+        if (init.seat_capabilities == null) return;
+
+        app.callbacks.clearRetainingCapacity();
+        try app.callbacks.put(app.display.id, displayHandler);
+
+        if (init.touch != null and init.keyboard == null) {
+            // mobile
+            app.state = .{ .run_mobile = .{
+                .width = init.toplevel_config.?.width,
+                .height = init.toplevel_config.?.height,
+                .pool = try Pool.init(app.ally, app.shm),
+                .touch = init.touch.?,
+            } };
+            try app.callbacks.put(app.xdg_wmbase.id, wmbaseHandler);
+            try app.callbacks.put(app.xdg_toplevel.id, toplevelHandler);
+            // try app.callbacks.put(app.state.run_desktop.touch.id, touchMobileHandler);
+        } else if (init.keyboard != null and init.pointer != null) {
+            // desktop
+            app.state = .{ .run_desktop = .{
+                .width = init.toplevel_config.?.width,
+                .height = init.toplevel_config.?.height,
+                .pool = try Pool.init(app.ally, app.shm),
+                .keyboard = init.keyboard.?,
+                .pointer = init.pointer.?,
+                .mouse = .{ .x = 0, .y = 0 },
+            } };
+            try app.callbacks.put(app.state.run_desktop.pointer.id, pointerDesktopHandler);
+            try app.callbacks.put(app.state.run_desktop.keyboard.id, keyboardDesktopHandler);
+            try app.callbacks.put(app.xdg_surface.id, surfaceDesktopHandler);
+            try app.callbacks.put(app.xdg_wmbase.id, wmbaseHandler);
+            try app.callbacks.put(app.xdg_toplevel.id, toplevelHandler);
+        } else {
+            @panic("no keyboard or touch");
+        }
+    }
+};
+
+fn surfaceInitHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.xdg.Surface.Event, header, body);
+    switch (event) {
+        .configure => |conf| {
+            try app.xdg_surface.ack_configure(conf.serial);
+            std.debug.assert(app.state.init.toplevel_config != null);
+            app.state.init.surface_configured = true;
+            try app.checkInit();
+        },
+    }
+}
+
+fn toplevelInitHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.xdg.Toplevel.Event, header, body);
+    switch (event) {
+        .configure => |conf| {
+            var width = conf.width;
+            var height = conf.height;
+            if (conf.width == 0) {
+                width = 128;
+                height = 128;
+            }
+            app.state.init.toplevel_config = .{
+                .width = @intCast(width),
+                .height = @intCast(height),
+            };
+        },
+        else => {
+            std.log.info("toplevel event: {}", .{event});
+        },
+    }
+}
+
+fn seatInitHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.core.Seat.Event, header, body);
+    const seat = wayland.core.Seat.init(app.conn, header.object_id); // TODO: pass into cb
+    switch (event) {
+        .capabilities => |capabilities| {
+            const caps: wayland.core.Seat.Capability = @bitCast(capabilities.capability);
+            app.state.init.seat_capabilities = caps;
+
+            if (caps.pointer) {
+                app.state.init.pointer = try seat.get_pointer();
+            }
+            if (caps.touch) {
+                app.state.init.touch = try seat.get_touch();
+            }
+            if (caps.keyboard) {
+                app.state.init.keyboard = try seat.get_keyboard();
+            }
+
+            try app.checkInit();
+        },
+        .name => |name| {
+            std.debug.print("<- wl_seat.name = {s}\n", .{name.name});
+        },
+    }
+}
+
+fn displayHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.core.Display.Event, header, body);
+    switch (event) {
+        .@"error" => |err| std.debug.print("<- error({}): {} {s}\n", .{ err.object_id, err.code, err.message }),
+        .delete_id => |id| {
+            std.debug.print("id {} deleted\n", .{id});
+            app.conn.id_pool.destroy(id.id);
+        },
+    }
+}
+
+const Pool = struct {
+    fd: std.os.fd_t,
+    shm: wayland.core.ShmPool,
+    mem: []u8,
+    file_length: usize,
+    allocationTable: std.AutoHashMap(u32, Buffer),
+    const Buffer = struct {
+        offset: usize,
+        len: usize,
+        width: usize = 0,
+        height: usize = 0,
+    };
+
+    // Memory to store 4k screen pixels
+    // const UPPER_BOUND = 33_177_600;
+    // Memory to store 8k screen pixels
+    // const UPPER_BOUND = 132_710_400;
+
+    const UPPER_BOUND = (7680 * 4320 * 4);
+
+    fn init(allocator: std.mem.Allocator, shm: wayland.core.Shm) !Pool {
+        const pool_fd_1 = try std.os.memfd_create("my-wayland-framebuffer-1", 0);
+        const pool_bytes_1 = try std.os.mmap(
+            null,
+            UPPER_BOUND,
+            std.os.PROT.READ | std.os.PROT.WRITE,
+            std.os.MAP.SHARED,
+            pool_fd_1,
+            0,
+        );
+        const shm1 = try shm.create_pool(@intCast(pool_fd_1), @intCast(pool_bytes_1.len));
+        return Pool{
+            .fd = pool_fd_1,
+            .shm = shm1,
+            .mem = pool_bytes_1,
+            .file_length = 0,
+            .allocationTable = std.AutoHashMap(u32, Buffer).init(allocator),
+        };
+    }
+
+    fn getFramebuffer(pool: *Pool, size: [2]u32) !Canvas {
+        var iter = pool.allocationTable.iterator();
+        var first_offset: usize = std.math.maxInt(usize);
+        var total_len: usize = 0;
+        while (iter.next()) |entry| {
+            const offset = entry.value_ptr.offset;
+            const len = entry.value_ptr.len;
+            total_len += len;
+            if (offset < first_offset) {
+                if (first_offset != std.math.maxInt(usize)) {
+                    total_len += first_offset - offset;
+                }
+                first_offset = offset;
+            }
+        }
+        const pixel_count = size[0] * size[1];
+        const byte_count = pixel_count * @sizeOf(Pixel);
+        var alloc_offset: usize = 0;
+        if (byte_count < first_offset) {
+            alloc_offset = 0;
+        } else {
+            alloc_offset = first_offset + total_len;
+        }
+        const final_offset = alloc_offset + byte_count;
+        if (final_offset > pool.file_length) {
+            try std.os.ftruncate(pool.fd, final_offset);
+            pool.file_length = final_offset;
+        }
+
+        const buffer = try pool.shm.create_buffer(
+            @intCast(alloc_offset),
+            @intCast(size[0]),
+            @intCast(size[1]),
+            @intCast(size[0] * @sizeOf(Pixel)),
+            .argb8888,
+        );
+
+        try pool.allocationTable.put(buffer.id, .{
+            .offset = alloc_offset,
+            .len = byte_count,
+            .width = size[0],
+            .height = size[1],
+        });
+
+        return .{
+            .pool = pool,
+            .buffer = buffer,
+            .fb = @as([*]Pixel, @ptrCast(pool.mem[alloc_offset..].ptr))[0..pixel_count],
+            .size = size,
+        };
+    }
+
+    fn freeFramebuffer(pool: *Pool, buffer_id: u32) !void {
+        std.debug.assert(pool.allocationTable.remove(buffer_id));
+    }
+};
+
+const Canvas = struct {
+    pool: *Pool,
+    fb: []Pixel,
+    buffer: wayland.core.Buffer,
+    size: [2]u32,
+
+    fn attach(canvas: Canvas, surface: wayland.core.Surface) !void {
+        try surface.attach(canvas.buffer, 0, 0);
+        try surface.damage(0, 0, std.math.maxInt(i32), std.math.maxInt(i32));
+        try surface.commit();
+    }
+
+    fn renderGradient(canvas: Canvas) void {
+        const fb = canvas.fb;
+        const width = canvas.size[0];
+        const height = canvas.size[1];
+        for (0..height) |y| {
+            const row = fb[y * width .. (y + 1) * width];
+            for (row, 0..width) |*pixel, x| {
+                pixel.* = .{
+                    @truncate(x),
+                    @truncate(y),
+                    0x00,
+                    0xFF,
+                };
+            }
+        }
+    }
+};
+
+fn wmbaseHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.xdg.WmBase.Event, header, body);
+    switch (event) {
+        .ping => |ping| {
+            try app.xdg_wmbase.pong(ping.serial);
+        },
+    }
+}
+
+fn toplevelHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.xdg.Toplevel.Event, header, body);
+    switch (event) {
+        .configure => |conf| {
+            var width = conf.width;
+            var height = conf.height;
+            if (conf.width == 0) {
+                width = 128;
+                height = 128;
+            }
+            if (app.state == .run_mobile) {
+                app.state.run_mobile.width = @intCast(width);
+                app.state.run_mobile.height = @intCast(height);
+            } else {
+                app.state.run_desktop.width = @intCast(width);
+                app.state.run_desktop.height = @intCast(height);
+            }
+        },
+        else => {
+            std.log.info("toplevel event: {}", .{event});
+        },
+    }
+}
+
+fn surfaceDesktopHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.xdg.Surface.Event, header, body);
+    switch (event) {
+        .configure => |conf| {
+            try app.xdg_surface.ack_configure(conf.serial);
+            const pool = if (app.state == .run_mobile) &app.state.run_mobile.pool else &app.state.run_desktop.pool;
+            const width = if (app.state == .run_mobile) app.state.run_mobile.width else app.state.run_desktop.width;
+            const height = if (app.state == .run_mobile) app.state.run_mobile.height else app.state.run_desktop.height;
+
+            // render
+            const canvas = try pool.getFramebuffer(.{ width, height });
+            canvas.renderGradient();
+            try canvas.attach(app.surface);
+            try app.callbacks.put(canvas.buffer.id, bufferHandler);
+        },
+    }
+}
+
+fn pointerDesktopHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.core.Pointer.Event, header, body);
+    switch (event) {
+        .enter => |enter| {
+            app.state.run_desktop.mouse.x = @floatFromInt(enter.surface_x);
+            app.state.run_desktop.mouse.y = @floatFromInt(enter.surface_y);
+        },
+        .leave => |_| {},
+        .motion => |motion| {
+            app.state.run_desktop.mouse.x = @floatFromInt(motion.surface_x);
+            app.state.run_desktop.mouse.y = @floatFromInt(motion.surface_y);
+        },
+        else => {
+            std.log.info("pointer event: {}", .{event});
+        },
+        // .button => |button| { _ = button; },
+        // .axis => |axis| { _ = axis;},
+        // .frame => {},
+        // .axis_source => |axis_source| { _ = axis_source; },
+        // .axis_stop => |axis_stop| { _ = axis_stop; },
+        // .axis_discrete => |axis_discrete| { _ = axis_discrete; },
+        // .axis_value120 => |axis_value120| { _ = axis_value120; },
+        // .axis_relative_direction => |axis_relative_direction| {_ = axis_relative_direction; },
+    }
+}
+
+fn keyboardDesktopHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.core.Keyboard.Event, header, body);
+    _ = app;
+    switch (event) {
+        else => {
+            std.log.info("keyboard event: {}", .{event});
+        },
+        // .button => |button| { _ = button; },
+        // .axis => |axis| { _ = axis;},
+        // .frame => {},
+        // .axis_source => |axis_source| { _ = axis_source; },
+        // .axis_stop => |axis_stop| { _ = axis_stop; },
+        // .axis_discrete => |axis_discrete| { _ = axis_discrete; },
+        // .axis_value120 => |axis_value120| { _ = axis_value120; },
+        // .axis_relative_direction => |axis_relative_direction| {_ = axis_relative_direction; },
+    }
+}
+
+fn bufferHandler(app: *App, header: wayland.Header, body: []const u32) !void {
+    const event = try wayland.deserialize(wayland.core.Buffer.Event, header, body);
+    std.debug.assert(event == .release);
+    const pool = if (app.state == .run_mobile) &app.state.run_mobile.pool else &app.state.run_desktop.pool;
+    try pool.freeFramebuffer(header.object_id);
+}
diff --git a/src/root.zig b/src/root.zig
index 79b7bf5..fa33084 100644
--- a/src/root.zig
+++ b/src/root.zig
@@ -557,8 +557,10 @@ pub fn Context(comptime T: []const type) type {
     const Item = struct { version: u32, index: u32 };
     const Pair = struct { []const u8, Item };
     comptime var kvs_list: []const Pair = &[_]Pair{};
+    comptime var name_list: []const []const u8 = &[_][]const u8{};
     inline for (T, 0..) |t, i| {
         kvs_list = kvs_list ++ &[_]Pair{.{ t.INTERFACE, .{ .version = t.VERSION, .index = i } }};
+        name_list = name_list ++ &[_][]const u8{t.INTERFACE};
     }
     const stringToType = std.ComptimeStringMap(Item, kvs_list);
 
@@ -566,6 +568,8 @@ pub fn Context(comptime T: []const type) type {
         conn: *Conn,
         global_ids: [T.len]?u32,
 
+        const global_names = name_list;
+
         pub fn init(conn: *Conn) !@This() {
             var ctx = @This(){
                 .conn = conn,
@@ -575,6 +579,14 @@ pub fn Context(comptime T: []const type) type {
             return ctx;
         }
 
+        pub fn getGlobalObjectName(ctx: *@This(), id: u32) ?[]const u8 {
+            for (ctx.global_ids, 0..) |gid_opt, i| {
+                const gid = gid_opt orelse continue;
+                if (gid == id) return global_names[i];
+            }
+            return null;
+        }
+
         pub fn getGlobal(ctx: *@This(), comptime G: type) !G {
             if (G == core.Display) return .{ .id = 1, .conn = ctx.conn };
             const g = stringToType.get(G.INTERFACE) orelse return error.NoSuchGlobal;
@@ -598,7 +610,6 @@ pub fn Context(comptime T: []const type) type {
                 try ctx.conn.socket.writeAll(std.mem.sliceAsBytes(message));
             }
 
-            // var ids: [T.len]?u32 = [_]?u32{null} ** T.len;
             var message_buffer = std.ArrayList(u32).init(ctx.conn.allocator);
             defer message_buffer.deinit();
             while (true) {
@@ -636,7 +647,7 @@ pub fn Context(comptime T: []const type) type {
                 } else if (header.object_id == registry_done_id) {
                     break;
                 } else {
-                    std.log.info("{} {x} \"{}\"", .{
+                    std.log.info("registerGlobals: {} {x} \"{}\"", .{
                         header.object_id,
                         header.size_and_opcode.opcode,
                         std.zig.fmtEscapes(std.mem.sliceAsBytes(message_buffer.items)),
diff --git a/src/xdg.zig b/src/xdg.zig
index f205f5d..a27fe41 100644
--- a/src/xdg.zig
+++ b/src/xdg.zig
@@ -63,6 +63,14 @@ pub const WmBase = struct {
         );
         return Surface.init(base.conn, new_id);
     }
+
+    pub fn pong(base: WmBase, serial: u32) !void {
+        try base.conn.send(
+            Request,
+            base.id,
+            .{ .pong = .{ .serial = serial } },
+        );
+    }
 };
 
 pub const Surface = struct {