diff --git a/pkg/macos/foundation.zig b/pkg/macos/foundation.zig
index 309da9675..3471c1757 100644
--- a/pkg/macos/foundation.zig
+++ b/pkg/macos/foundation.zig
@@ -1,5 +1,6 @@
 pub const c = @import("foundation/c.zig");
 pub usingnamespace @import("foundation/array.zig");
+pub usingnamespace @import("foundation/attributed_string.zig");
 pub usingnamespace @import("foundation/base.zig");
 pub usingnamespace @import("foundation/data.zig");
 pub usingnamespace @import("foundation/dictionary.zig");
diff --git a/pkg/macos/foundation/attributed_string.zig b/pkg/macos/foundation/attributed_string.zig
new file mode 100644
index 000000000..1194924af
--- /dev/null
+++ b/pkg/macos/foundation/attributed_string.zig
@@ -0,0 +1,72 @@
+const std = @import("std");
+const assert = std.debug.assert;
+const Allocator = std.mem.Allocator;
+const foundation = @import("../foundation.zig");
+const text = @import("../text.zig");
+const c = @import("c.zig");
+
+pub const MutableAttributedString = opaque {
+    pub fn create(cap: usize) Allocator.Error!*MutableAttributedString {
+        return @intToPtr(
+            ?*MutableAttributedString,
+            @ptrToInt(c.CFAttributedStringCreateMutable(
+                null,
+                @intCast(c.CFIndex, cap),
+            )),
+        ) orelse Allocator.Error.OutOfMemory;
+    }
+
+    pub fn release(self: *MutableAttributedString) void {
+        foundation.CFRelease(self);
+    }
+
+    pub fn replaceString(
+        self: *MutableAttributedString,
+        range: foundation.Range,
+        replacement: *foundation.String,
+    ) void {
+        c.CFAttributedStringReplaceString(
+            @ptrCast(c.CFMutableAttributedStringRef, self),
+            range.cval(),
+            @ptrCast(c.CFStringRef, replacement),
+        );
+    }
+
+    pub fn setAttribute(
+        self: *MutableAttributedString,
+        range: foundation.Range,
+        key: anytype,
+        value: ?*anyopaque,
+    ) void {
+        const T = @TypeOf(key);
+        const info = @typeInfo(T);
+        const Key = if (info != .Pointer) T else info.Pointer.child;
+        const key_arg = if (@hasDecl(Key, "key"))
+            key.key()
+        else
+            key;
+
+        c.CFAttributedStringSetAttribute(
+            @ptrCast(c.CFMutableAttributedStringRef, self),
+            range.cval(),
+            @ptrCast(c.CFStringRef, key_arg),
+            value,
+        );
+    }
+};
+
+test "mutable attributed string" {
+    //const testing = std.testing;
+
+    const str = try MutableAttributedString.create(0);
+    defer str.release();
+
+    {
+        const rep = try foundation.String.createWithBytes("hello", .utf8, false);
+        defer rep.release();
+        str.replaceString(foundation.Range.init(0, 0), rep);
+    }
+
+    str.setAttribute(foundation.Range.init(0, 0), text.FontAttribute.url, null);
+    str.setAttribute(foundation.Range.init(0, 0), text.FontAttribute.name.key(), null);
+}
diff --git a/pkg/macos/foundation/base.zig b/pkg/macos/foundation/base.zig
index b48d6df38..1b8f75661 100644
--- a/pkg/macos/foundation/base.zig
+++ b/pkg/macos/foundation/base.zig
@@ -1,5 +1,20 @@
+const c = @import("c.zig");
+
 pub const ComparisonResult = enum(c_int) {
     less = -1,
     equal = 0,
     greater = 1,
 };
+
+pub const Range = extern struct {
+    location: c.CFIndex,
+    length: c.CFIndex,
+
+    pub fn init(loc: usize, len: usize) Range {
+        return @bitCast(Range, c.CFRangeMake(@intCast(c_long, loc), @intCast(c_long, len)));
+    }
+
+    pub fn cval(self: Range) c.CFRange {
+        return @bitCast(c.CFRange, self);
+    }
+};