diff --git a/flake.lock b/flake.lock
new file mode 100644
index 00000000..ff6a61ab
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1769330179,
+        "narHash": "sha256-yxgb4AmkVHY5OOBrC79Vv6EVd4QZEotqv+6jcvA212M=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "48698d12cc10555a4f3e3222d9c669b884a49dfe",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/gcalcli/argparsers.py b/gcalcli/argparsers.py
index 023a338e..2707842e 100644
--- a/gcalcli/argparsers.py
+++ b/gcalcli/argparsers.py
@@ -609,6 +609,12 @@ def get_argument_parser():
         'from lavender, sage, grape, flamingo, banana, tangerine, '
         'peacock, graphite, blueberry, basil, tomato.',
     )
+    add.add_argument(
+        '--availability',
+        default='busy',
+        choices=['free', 'busy'],
+        help='Event availability (free/busy status). Default is busy.',
+    )
     add.add_argument('--title', default=None, type=str, help='Event title')
     add.add_argument(
         '--who',
diff --git a/gcalcli/cli.py b/gcalcli/cli.py
index 5f7ad1da..6a566bfe 100755
--- a/gcalcli/cli.py
+++ b/gcalcli/cli.py
@@ -304,7 +304,8 @@ def main():
 
             gcal.AddEvent(parsed_args.title, parsed_args.where, estart, eend,
                           parsed_args.description, parsed_args.who,
-                          parsed_args.reminders, parsed_args.event_color)
+                          parsed_args.reminders, parsed_args.event_color,
+                          parsed_args.availability)
 
         elif parsed_args.command == 'search':
             gcal.TextQuery(
diff --git a/gcalcli/details.py b/gcalcli/details.py
index acc4bac9..e549f106 100644
--- a/gcalcli/details.py
+++ b/gcalcli/details.py
@@ -356,6 +356,17 @@ class ID(SimpleSingleFieldHandler):
     fieldnames = ['id']
 
 
+class Availability(SimpleSingleFieldHandler):
+    """Handler for event availability (free/busy)."""
+
+    fieldnames = ['transparency']
+
+    @classmethod
+    def _get(cls, event):
+        val = event.get(cls.fieldnames[0], 'opaque')
+        return 'free' if val == 'transparent' else 'busy'
+
+
 class Action(SingleFieldHandler):
     """Handler specifying event processing during an update."""
 
@@ -377,6 +388,7 @@ def _get(cls, event):
                         ('calendar', Calendar),
                         ('email', Email),
                         ('attendees', Attendees),
+                        ('availability', Availability),
                         ('action', Action)])
 HANDLERS_READONLY = {Url, Calendar}
 
diff --git a/gcalcli/gcal.py b/gcalcli/gcal.py
index c8fb52f0..1d1ebe49 100644
--- a/gcalcli/gcal.py
+++ b/gcalcli/gcal.py
@@ -1464,12 +1464,14 @@ def QuickAddEvent(self, event_text, reminders=None):
 
         return new_event
 
-    def AddEvent(self, title, where, start, end, descr, who, reminders, color):
+    def AddEvent(self, title, where, start, end, descr, who, reminders, color,
+                 availability='busy'):
 
         calendar = self._prompt_for_calendar(self.cals)
 
         event = {}
         event['summary'] = title
+        event['transparency'] = 'transparent' if availability == 'free' else 'opaque'
 
         if self.options['allday']:
             event['start'] = {'date': start}
diff --git a/tests/test_gcalcli.py b/tests/test_gcalcli.py
index c6c4bf9a..35a3617f 100644
--- a/tests/test_gcalcli.py
+++ b/tests/test_gcalcli.py
@@ -393,3 +393,23 @@ def test_next_cut(PatchedGCalI):
 
     event_title = "樹貞 fun fun fun"
     assert gcal._next_cut(event_title) == (8, 6)
+
+def test_add_event_availability(PatchedGCalI):
+    cal_names = parse_cal_names(['jcrowgey@uw.edu'], printer=None)
+    gcal = PatchedGCalI(
+            cal_names=cal_names, allday=False, default_reminders=True)
+    assert gcal.AddEvent(title='transparent event',
+                         where='anywhere',
+                         start='now',
+                         end='tomorrow',
+                         descr='testing',
+                         who='anyone',
+                         reminders=None,
+                         color='banana',
+                         availability='free')
+
+    gcal.api_tracker.verify_all_mutating_calls([
+        CallMatcher('insert',
+                    body_has_fields={'summary', 'start', 'end', 'transparency'},
+                    body_fields={'transparency': 'transparent'})
+    ])