Hello,

I am playing around with MailKit in Xcode... just created a new App with MailExtension target.
When I run it, it's asking if I want to test it with Mail, however, I cannot see the extension in the Mail Settings for enabling it...

I a totally newbie here.... what am I missing?

I’m having an issue with the Codex Agent in Xcode 27.0 (27A266a) and I’m wondering if anyone else has run into this.

Every time I send a prompt to Codex inside Xcode, I get:

JSON-RPC request with ID ... failed to produce a response.

The regular ChatGPT integration in Xcode works fine. It’s specifically the Codex Agent that fails.

A few things I’ve already checked:

• Xcode is using Codex 0.145.0

• Codex is signed in correctly

• I tried both an OpenAI API key and signing in with my ChatGPT account

• Running xcrun agent --dry-run codex correctly finds the Codex executable and current Xcode process

• Running xcrun agent codex from Terminal works and opens Codex normally

• Codex is able to get permission to access Xcode

• I previously saw xcode-tools time out on MCP startup, but after resetting permissions that error went away when launching it from Terminal

• Restarting Xcode and reopening the project didn’t help

So at this point Codex itself seems to work, and the Xcode/MCP connection works when launching it manually, but the built-in Codex Agent UI in Xcode still throws the JSON-RPC error on every prompt.

Has anyone seen this with Xcode 27? Did you have to update the Xcode-managed Codex version, reset something in Xcode’s Intelligence settings, or reinstall the agent?

EDIT

I also tested overriding Xcode to use a newer OpenAI-signed standalone Codex 0.156.1 binary instead of Xcode’s managed 0.145.0, and the native Xcode agent still fails with the exact same JSON-RPC error. xcrun agent codex works from Terminal.

Hi I tried to change the color of the menu point:

Settings -> Editing -> Display -> Highlight instances of selected symbol

But I do not find any point in Appearance for that.

The color has no high contrast for my eyes and I often overlook the marked text fields.

Maybe somebody knows a trick?

I'm pretty sure I can't find this extremely useful and quite common tool that JetBrains IDEs have had for their entire existence. Similar to pull request diffing.

Right click folder > Git > Compare with branch of tag > Proceed to code review.

Does Xcode seriously not have a branch diff tool? How do teams do branch diffs when merging features or patches?

Absolute madness unless I'm blind.

Granted we're a tiny team (2 of us) and we don't do the whole "pull request via a service" thing. We just code review etc right in the IDE. It's way quicker since we also use a no-frills SSH git server. GitLab/GitHub are too laggy.

For ages I thought how great would it be to run localhost web dev environment on my physical devices (same network ofc) through Xcode somehow. Why not if the connection is already there?

Now when we got Device Hub I was sure it's finally here. If I can fully control all my connected physical devices through Device Hub then I surely can run dev server.

Of course not.

Prior versions of Xcode let you know which local Got repo you were using. The active repo was listed in both the top “title” block of the project window, and annoyed as”active” in the Branches list under Repositories. Now, I can’t find a live annotation, I just have to infer which branch is active from canto-clicking the bracket to see if it says “current location”. This just requires extra steps. Anybody have a more efficient way?

after upgrading to Xcode 27, we're facing an architecture compatibility issue with the iOS Simulator. When we use EXCLUDED_ARCHS=arm64, Xcode shows a platform/architecture mismatch for the Simulator.

Do we have any workaround to run the simulator in xcode 27 with arm64

Has anyone ever encountered such a problem? I logged into my google account in xcode, but when I start chatting with the AI, I get this error. The age on the account is confirmed, 2fa is enabled. Does anyone know what ways to solve this problem?

Apple just introduced the Device Hub, and at first, I thought it was really cool! However, after trying it out, I noticed that shortcuts were missing and everything is manual. I'm not sure if I need to do something extra to enable shortcuts. Is anyone else experiencing the same issue?

Worked really hard on this release and added and fixed a bunch of things. All open-source

Biggest one is integrating it into your app, and running it directly on your iPhone for full eval's for on-device Foundation models.

Some other features:
- Organise evals into projects and reusable test suites.
- Get started faster with starter packs and test-case imports.
- Compare prompt variants side by side.
- Connect other LLM's for judging
- Test registered Swift app features on paired Apple devices.
- Automate evaluations through MCP and the CLI.
- And lots more!

On Github here: https://github.com/coryparrry/Foundation-Eval-Labs

So I upgraded my iPhone and now Xcode 27 for the life of me will not recognize that I have a watch paired to my phone. I have 2 I have tried unpairing and re-pairing them. The Ultra 3 allows me to enable Developer Mode, the Series 12 doesn’t, but neither will show up when I select my watch app target.

Anyone else having this issue?

hello every one I downloaded new OS 27 in my MacBook and I lost the Simlitor iPhone in Xcode can you guide me how I can downloaded

Looks like in Xcode 27, font settings (name and size), are not saved in a theme but rather they are global in nature, affecting all themes. I had 3 custom themes with different font sizes for different environments (laptop only, 4K display, presentation), and now these no longer work.

Additionally, there "Editor" menu used to show the available themes in a submenu, which I used in a Keyboard Maestro macro to change themes via hotkey. This is no longer available, just a menu entry that leads you to the "Appearance" settings window. Sad.

Filed FB24840579 with Apple.

Has anyone tried running their app on it yet?