diff --git a/include/ghostty.h b/include/ghostty.h
index af3aa1fa7..a6fc51d9b 100644
--- a/include/ghostty.h
+++ b/include/ghostty.h
@@ -233,6 +233,7 @@ typedef enum {
 typedef enum {
     GHOSTTY_BINDING_COPY_TO_CLIPBOARD,
     GHOSTTY_BINDING_PASTE_FROM_CLIPBOARD,
+    GHOSTTY_BINDING_NEW_TAB,
 } ghostty_binding_action_e;
 
 // Fully defined types. This MUST be kept in sync with equivalent Zig
@@ -242,6 +243,7 @@ typedef struct {
     void *userdata;
     void *nsview;
     double scale_factor;
+    uint16_t font_size;
 } ghostty_surface_config_s;
 
 typedef void (*ghostty_runtime_wakeup_cb)(void *);
@@ -250,6 +252,7 @@ typedef void (*ghostty_runtime_set_title_cb)(void *, const char *);
 typedef const char* (*ghostty_runtime_read_clipboard_cb)(void *, ghostty_clipboard_e);
 typedef void (*ghostty_runtime_write_clipboard_cb)(void *, const char *, ghostty_clipboard_e);
 typedef void (*ghostty_runtime_new_split_cb)(void *, ghostty_split_direction_e);
+typedef void (*ghostty_runtime_new_tab_cb)(void *, ghostty_surface_config_s);
 typedef void (*ghostty_runtime_close_surface_cb)(void *, bool);
 typedef void (*ghostty_runtime_focus_split_cb)(void *, ghostty_split_focus_direction_e);
 typedef void (*ghostty_runtime_goto_tab_cb)(void *, int32_t);
@@ -264,6 +267,7 @@ typedef struct {
     ghostty_runtime_read_clipboard_cb read_clipboard_cb;
     ghostty_runtime_write_clipboard_cb write_clipboard_cb;
     ghostty_runtime_new_split_cb new_split_cb;
+    ghostty_runtime_new_tab_cb new_tab_cb;
     ghostty_runtime_close_surface_cb close_surface_cb;
     ghostty_runtime_focus_split_cb focus_split_cb;
     ghostty_runtime_goto_tab_cb goto_tab_cb;
@@ -289,6 +293,8 @@ bool ghostty_app_tick(ghostty_app_t);
 void *ghostty_app_userdata(ghostty_app_t);
 void ghostty_app_keyboard_changed(ghostty_app_t);
 
+ghostty_surface_config_s ghostty_surface_config_new();
+
 ghostty_surface_t ghostty_surface_new(ghostty_app_t, ghostty_surface_config_s*);
 void ghostty_surface_free(ghostty_surface_t);
 ghostty_app_t ghostty_surface_app(ghostty_surface_t);
diff --git a/macos/Sources/AppDelegate.swift b/macos/Sources/AppDelegate.swift
index 066401056..fa468221d 100644
--- a/macos/Sources/AppDelegate.swift
+++ b/macos/Sources/AppDelegate.swift
@@ -81,11 +81,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, ObservableObject {
     }
     
     @IBAction func newTab(_ sender: Any?) {
-        if let existingWindow = windowManager.mainWindow {
-            windowManager.addNewTab(to: existingWindow)
-        } else {
-            windowManager.addNewWindow()
-        }
+        windowManager.newTab()
     }
     
     @IBAction func closeWindow(_ sender: Any) {
diff --git a/macos/Sources/Features/Primary Window/PrimaryView.swift b/macos/Sources/Features/Primary Window/PrimaryView.swift
index 221c50078..b62e630b7 100644
--- a/macos/Sources/Features/Primary Window/PrimaryView.swift	
+++ b/macos/Sources/Features/Primary Window/PrimaryView.swift	
@@ -11,6 +11,9 @@ struct PrimaryView: View {
     // We need this to report back up the app controller which surface in this view is focused.
     let focusedSurfaceWrapper: FocusedSurfaceWrapper
     
+    // If this is set, this is the base configuration that we build our surface out of.
+    let baseConfig: ghostty_surface_config_s?
+    
     // We need access to our window to know if we're the key window to determine
     // if we show the quit confirmation or not.
     @State private var window: NSWindow?
@@ -71,7 +74,7 @@ struct PrimaryView: View {
                 self.appDelegate.confirmQuit = $0
             })
             
-            Ghostty.TerminalSplit(onClose: Self.closeWindow)
+            Ghostty.TerminalSplit(onClose: Self.closeWindow, baseConfig: self.baseConfig)
                 .ghosttyApp(ghostty.app!)
                 .background(WindowAccessor(window: $window))
                 .onReceive(gotoTab) { onGotoTab(notification: $0) }
diff --git a/macos/Sources/Features/Primary Window/PrimaryWindow.swift b/macos/Sources/Features/Primary Window/PrimaryWindow.swift
index 85ca49601..6f6e0ba73 100644
--- a/macos/Sources/Features/Primary Window/PrimaryWindow.swift	
+++ b/macos/Sources/Features/Primary Window/PrimaryWindow.swift	
@@ -16,7 +16,7 @@ class FocusedSurfaceWrapper {
 class PrimaryWindow: NSWindow {
     var focusedSurfaceWrapper: FocusedSurfaceWrapper = FocusedSurfaceWrapper()
 
-    static func create(ghostty: Ghostty.AppState, appDelegate: AppDelegate) -> PrimaryWindow {
+    static func create(ghostty: Ghostty.AppState, appDelegate: AppDelegate, baseConfig: ghostty_surface_config_s? = nil) -> PrimaryWindow {
         let window = PrimaryWindow(
             contentRect: NSRect(x: 0, y: 0, width: 800, height: 600),
             styleMask: [.titled, .closable, .miniaturizable, .resizable],
@@ -27,7 +27,9 @@ class PrimaryWindow: NSWindow {
         window.contentView = NSHostingView(rootView: PrimaryView(
             ghostty: ghostty,
             appDelegate: appDelegate,
-            focusedSurfaceWrapper: window.focusedSurfaceWrapper))
+            focusedSurfaceWrapper: window.focusedSurfaceWrapper,
+            baseConfig: baseConfig
+        ))
         
         // We do want to cascade when new windows are created
         window.windowController?.shouldCascadeWindows = true
diff --git a/macos/Sources/Features/Primary Window/PrimaryWindowController.swift b/macos/Sources/Features/Primary Window/PrimaryWindowController.swift
index ffc7d12f5..a77aebf28 100644
--- a/macos/Sources/Features/Primary Window/PrimaryWindowController.swift	
+++ b/macos/Sources/Features/Primary Window/PrimaryWindowController.swift	
@@ -7,8 +7,8 @@ class PrimaryWindowController: NSWindowController {
     // This is required for the "+" button to show up in the tab bar to add a
     // new tab.
     override func newWindowForTab(_ sender: Any?) {
-        guard let window = self.window else { preconditionFailure("Expected window to be loaded") }
+        guard let window = self.window as? PrimaryWindow else { preconditionFailure("Expected window to be loaded") }
         guard let manager = self.windowManager else { return }
-        manager.addNewTab(to: window)
+        manager.triggerNewTab(for: window)
     }
 }
diff --git a/macos/Sources/Features/Primary Window/PrimaryWindowManager.swift b/macos/Sources/Features/Primary Window/PrimaryWindowManager.swift
index 16b241070..987dc86a2 100644
--- a/macos/Sources/Features/Primary Window/PrimaryWindowManager.swift	
+++ b/macos/Sources/Features/Primary Window/PrimaryWindowManager.swift	
@@ -1,5 +1,7 @@
 import Cocoa
 import Combine
+import GhosttyKit
+import SwiftUI
 
 // PrimaryWindowManager manages the windows and tabs in the primary window
 // of the application. It keeps references to windows and cleans them up when
@@ -43,6 +45,22 @@ class PrimaryWindowManager {
     
     init(ghostty: Ghostty.AppState) {
         self.ghostty = ghostty
+        
+        // Register self as observer for the NewTab notification that
+        // is triggered via callback from Zig code.
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(onNewTab),
+            name: Ghostty.Notification.ghosttyNewTab,
+            object: nil)
+    }
+    
+    deinit {
+        // Clean up the observer.
+        NotificationCenter.default.removeObserver(
+            self,
+            name: Ghostty.Notification.ghosttyNewTab,
+            object: nil)
     }
     
     /// Add the initial window for the application. This should only be called once from the AppDelegate.
@@ -61,16 +79,41 @@ class PrimaryWindowManager {
         newWindow.makeKeyAndOrderFront(nil)
     }
     
-    func addNewTab(to window: NSWindow) {
-        guard let controller = createWindowController() else { return }
+    // triggerNewTab tells the Zig core code to create a new tab, which then calls
+    // back into Swift code.
+    func triggerNewTab(for window: PrimaryWindow) {
+        guard let surface = window.focusedSurfaceWrapper.surface else { return }
+        ghostty.newTab(surface: surface)
+    }
+    
+    func newTab() {
+        if let window = mainWindow as? PrimaryWindow {
+            self.triggerNewTab(for: window)
+        } else {
+            self.addNewWindow()
+        }
+    }
+
+    @objc private func onNewTab(notification: SwiftUI.Notification) {
+        guard let surfaceView = notification.object as? Ghostty.SurfaceView else { return }
+        guard let window = surfaceView.window else { return }
+        
+        let configAny = notification.userInfo?[Ghostty.Notification.NewTabKey]
+        let config = configAny as? ghostty_surface_config_s
+        
+        self.addNewTab(to: window, withBaseConfig: config)
+    }
+    
+    private func addNewTab(to window: NSWindow, withBaseConfig config: ghostty_surface_config_s? = nil) {
+        guard let controller = createWindowController(withBaseConfig: config) else { return }
         guard let newWindow = addManagedWindow(windowController: controller)?.window else { return  }
         window.addTabbedWindow(newWindow, ordered: .above)
         newWindow.makeKeyAndOrderFront(nil)
     }
 
-    private func createWindowController() -> PrimaryWindowController? {
+    private func createWindowController(withBaseConfig config: ghostty_surface_config_s? = nil) -> PrimaryWindowController? {
         guard let appDelegate = NSApplication.shared.delegate as? AppDelegate else { return nil }
-        let window = PrimaryWindow.create(ghostty: ghostty, appDelegate: appDelegate)
+        let window = PrimaryWindow.create(ghostty: ghostty, appDelegate: appDelegate, baseConfig: config)
         Self.lastCascadePoint = window.cascadeTopLeft(from: Self.lastCascadePoint)
         let controller = PrimaryWindowController(window: window)
         controller.windowManager = self
diff --git a/macos/Sources/Ghostty/AppState.swift b/macos/Sources/Ghostty/AppState.swift
index 68076c224..1a0a17f4b 100644
--- a/macos/Sources/Ghostty/AppState.swift
+++ b/macos/Sources/Ghostty/AppState.swift
@@ -61,6 +61,7 @@ extension Ghostty {
                 read_clipboard_cb: { userdata, loc in AppState.readClipboard(userdata, location: loc) },
                 write_clipboard_cb: { userdata, str, loc in AppState.writeClipboard(userdata, string: str, location: loc) },
                 new_split_cb: { userdata, direction in AppState.newSplit(userdata, direction: direction) },
+                new_tab_cb: { userdata, surfaceConfig in AppState.newTab(userdata, config: surfaceConfig) },
                 close_surface_cb: { userdata, processAlive in AppState.closeSurface(userdata, processAlive: processAlive) },
                 focus_split_cb: { userdata, direction in AppState.focusSplit(userdata, direction: direction) },
                 goto_tab_cb: { userdata, n in AppState.gotoTab(userdata, n: n) },
@@ -137,6 +138,10 @@ extension Ghostty {
             ghostty_surface_request_close(surface)
         }
         
+        func newTab(surface: ghostty_surface_t) {
+            ghostty_surface_binding_action(surface, GHOSTTY_BINDING_NEW_TAB, nil)
+        }
+        
         func split(surface: ghostty_surface_t, direction: ghostty_split_direction_e) {
             ghostty_surface_split(surface, direction)
         }
@@ -258,6 +263,19 @@ extension Ghostty {
             )
         }
         
+        static func newTab(_ userdata: UnsafeMutableRawPointer?, config: ghostty_surface_config_s) {
+            guard let surface = self.surfaceUserdata(from: userdata) else { return }
+            
+            var userInfo: [AnyHashable : Any] = [:];
+            userInfo[Notification.NewTabKey] = config;
+            
+            NotificationCenter.default.post(
+                name: Notification.ghosttyNewTab,
+                object: surface,
+                userInfo: userInfo
+            )
+        }
+        
         /// Returns the GhosttyState from the given userdata value.
         static private func appState(fromSurface userdata: UnsafeMutableRawPointer?) -> AppState? {
             let surfaceView = Unmanaged<SurfaceView>.fromOpaque(userdata!).takeUnretainedValue()
diff --git a/macos/Sources/Ghostty/Ghostty.SplitView.swift b/macos/Sources/Ghostty/Ghostty.SplitView.swift
index cc0f72487..a3e224139 100644
--- a/macos/Sources/Ghostty/Ghostty.SplitView.swift
+++ b/macos/Sources/Ghostty/Ghostty.SplitView.swift
@@ -8,10 +8,11 @@ extension Ghostty {
     struct TerminalSplit: View {
         @Environment(\.ghosttyApp) private var app
         let onClose: (() -> Void)?
+        let baseConfig: ghostty_surface_config_s?
         
         var body: some View {
             if let app = app {
-                TerminalSplitRoot(app: app, onClose: onClose)
+                TerminalSplitRoot(app: app, onClose: onClose, baseConfig: baseConfig)
             }
         }
     }
@@ -67,9 +68,9 @@ extension Ghostty {
             @Published var surface: SurfaceView
             
             /// Initialize a new leaf which creates a new terminal surface.
-            init(_ app: ghostty_app_t) {
+            init(_ app: ghostty_app_t, _ baseConfig: ghostty_surface_config_s?) {
                 self.app = app
-                self.surface = SurfaceView(app)
+                self.surface = SurfaceView(app, baseConfig)
             }
         }
         
@@ -87,7 +88,7 @@ extension Ghostty {
                 // Initially, both topLeft and bottomRight are in the "nosplit"
                 // state since this is a new split.
                 self.topLeft = .noSplit(from)
-                self.bottomRight = .noSplit(.init(app))
+                self.bottomRight = .noSplit(.init(app, nil))
             }
         }
         
@@ -141,12 +142,14 @@ extension Ghostty {
         @State private var node: SplitNode
         @State private var requestClose: Bool = false
         let onClose: (() -> Void)?
+        let baseConfig: ghostty_surface_config_s?
         
         @FocusedValue(\.ghosttySurfaceTitle) private var surfaceTitle: String?
         
-        init(app: ghostty_app_t, onClose: (() ->Void)? = nil) {
+        init(app: ghostty_app_t, onClose: (() ->Void)? = nil, baseConfig: ghostty_surface_config_s? = nil) {
             self.onClose = onClose
-            _node = State(wrappedValue: SplitNode.noSplit(.init(app)))
+            self.baseConfig = baseConfig
+            _node = State(wrappedValue: SplitNode.noSplit(.init(app, baseConfig)))
         }
         
         var body: some View {
diff --git a/macos/Sources/Ghostty/Package.swift b/macos/Sources/Ghostty/Package.swift
index d4b3a9fa9..006433c72 100644
--- a/macos/Sources/Ghostty/Package.swift
+++ b/macos/Sources/Ghostty/Package.swift
@@ -78,6 +78,10 @@ extension Ghostty.Notification {
     /// Goto tab. Has tab index in the userinfo.
     static let ghosttyGotoTab = Notification.Name("com.mitchellh.ghostty.gotoTab")
     static let GotoTabKey = ghosttyGotoTab.rawValue
+    
+    /// New tab. Has base surface config requestesd in userinfo.
+    static let ghosttyNewTab = Notification.Name("com.mitchellh.ghostty.newTab")
+    static let NewTabKey = ghosttyNewTab.rawValue
 
     /// Toggle fullscreen of current window
     static let ghosttyToggleFullscreen = Notification.Name("com.mitchellh.ghostty.toggleFullscreen")
diff --git a/macos/Sources/Ghostty/SurfaceView.swift b/macos/Sources/Ghostty/SurfaceView.swift
index cad0fdbd5..11f809fc9 100644
--- a/macos/Sources/Ghostty/SurfaceView.swift
+++ b/macos/Sources/Ghostty/SurfaceView.swift
@@ -24,7 +24,7 @@ extension Ghostty {
         @StateObject private var surfaceView: SurfaceView
         
         init(_ app: ghostty_app_t, @ViewBuilder content: @escaping ((SurfaceView) -> Content)) {
-            _surfaceView = StateObject(wrappedValue: SurfaceView(app))
+            _surfaceView = StateObject(wrappedValue: SurfaceView(app, nil))
             self.content = content
         }
         
@@ -137,7 +137,7 @@ extension Ghostty {
         // so we'll use that to tell ghostty to refresh.
         override var wantsUpdateLayer: Bool { return true }
         
-        init(_ app: ghostty_app_t) {
+        init(_ app: ghostty_app_t, _ baseConfig: ghostty_surface_config_s?) {
             self.markedText = NSMutableAttributedString()
             
             // Initialize with some default frame size. The important thing is that this
@@ -146,10 +146,11 @@ extension Ghostty {
             super.init(frame: NSMakeRect(0, 0, 800, 600))
             
             // Setup our surface. This will also initialize all the terminal IO.
-            var surface_cfg = ghostty_surface_config_s(
-                userdata: Unmanaged.passUnretained(self).toOpaque(),
-                nsview: Unmanaged.passUnretained(self).toOpaque(),
-                scale_factor: NSScreen.main!.backingScaleFactor)
+            var surface_cfg = baseConfig ?? ghostty_surface_config_new()
+            surface_cfg.userdata = Unmanaged.passUnretained(self).toOpaque()
+            surface_cfg.nsview = Unmanaged.passUnretained(self).toOpaque()
+            surface_cfg.scale_factor = NSScreen.main!.backingScaleFactor
+            
             guard let surface = ghostty_surface_new(app, &surface_cfg) else {
                 self.error = AppError.surfaceCreateError
                 return
diff --git a/src/apprt/embedded.zig b/src/apprt/embedded.zig
index e1ef1612b..777b7870e 100644
--- a/src/apprt/embedded.zig
+++ b/src/apprt/embedded.zig
@@ -59,6 +59,9 @@ pub const App = struct {
         /// views then this can be null.
         new_split: ?*const fn (SurfaceUD, input.SplitDirection) callconv(.C) void = null,
 
+        /// New tab with options.
+        new_tab: ?*const fn (SurfaceUD, apprt.Surface.Options) callconv(.C) void = null,
+
         /// Close the current surface given by this function.
         close_surface: ?*const fn (SurfaceUD, bool) callconv(.C) void = null,
 
@@ -162,17 +165,23 @@ pub const Surface = struct {
         userdata: ?*anyopaque = null,
 
         /// The pointer to the backing NSView for the surface.
-        nsview: *anyopaque = undefined,
+        nsview: ?*anyopaque = null,
 
         /// The scale factor of the screen.
         scale_factor: f64 = 1,
+
+        /// The font size to inherit. If 0, default font size will be used.
+        font_size: u16 = 0,
     };
 
     pub fn init(self: *Surface, app: *App, opts: Options) !void {
+        const nsview = objc.Object.fromId(opts.nsview orelse
+            return error.NSViewMustBeSet);
+
         self.* = .{
             .app = app,
             .core_surface = undefined,
-            .nsview = objc.Object.fromId(opts.nsview),
+            .nsview = nsview,
             .content_scale = .{
                 .x = @floatCast(opts.scale_factor),
                 .y = @floatCast(opts.scale_factor),
@@ -201,6 +210,13 @@ pub const Surface = struct {
             self,
         );
         errdefer self.core_surface.deinit();
+
+        // If our options requested a specific font-size, set that.
+        if (opts.font_size != 0) {
+            var font_size = self.core_surface.font_size;
+            font_size.points = opts.font_size;
+            self.core_surface.setFontSize(font_size);
+        }
     }
 
     pub fn deinit(self: *Surface) void {
@@ -593,6 +609,22 @@ pub const Surface = struct {
         func(self.opts.userdata, nonNativeFullscreen);
     }
 
+    pub fn newTab(self: *const Surface) !void {
+        const func = self.app.opts.new_tab orelse {
+            log.info("runtime embedder does not support new_tab", .{});
+            return;
+        };
+
+        const font_size: u16 = font_size: {
+            if (!self.app.config.@"window-inherit-font-size") break :font_size 0;
+            break :font_size self.core_surface.font_size.points;
+        };
+
+        func(self.opts.userdata, .{
+            .font_size = font_size,
+        });
+    }
+
     /// The cursor position from the host directly is in screen coordinates but
     /// all our interface works in pixels.
     fn cursorPosToPixels(self: *const Surface, pos: apprt.CursorPos) !apprt.CursorPos {
@@ -662,6 +694,11 @@ pub const CAPI = struct {
         };
     }
 
+    /// Returns initial surface options.
+    export fn ghostty_surface_config_new() apprt.Surface.Options {
+        return .{};
+    }
+
     /// Create a new surface as part of an app.
     export fn ghostty_surface_new(
         app: *App,
@@ -817,6 +854,7 @@ pub const CAPI = struct {
         const action: input.Binding.Action = switch (key) {
             .copy_to_clipboard => .{ .copy_to_clipboard = {} },
             .paste_from_clipboard => .{ .paste_from_clipboard = {} },
+            .new_tab => .{ .new_tab = {} },
         };
 
         ptr.core_surface.performBindingAction(action) catch |err| {
diff --git a/src/input/Binding.zig b/src/input/Binding.zig
index 6431853bd..400e9695e 100644
--- a/src/input/Binding.zig
+++ b/src/input/Binding.zig
@@ -276,6 +276,7 @@ pub const Action = union(enum) {
 pub const Key = enum(c_int) {
     copy_to_clipboard,
     paste_from_clipboard,
+    new_tab,
 };
 
 /// Trigger is the associated key state that can trigger an action.