Xcode 26.3
Apple (RC xip, downloads, Hacker News):
Xcode 26.3 introduces support for agentic coding, a new way in Xcode for developers to build apps, powered by coding agents from Anthropic and OpenAI. With agentic coding, Xcode can work autonomously toward a developer’s goals — from breaking down tasks to making decisions based on the project architecture, and using built-in tools to get things done.
In addition to Anthropic’s Claude Agent and OpenAI’s Codex integrations, Xcode 26.3 makes its capabilities available through the Model Context Protocol, an open standard that gives developers the flexibility to use any compatible agent or tool with Xcode.
For more information, see Setting up coding intelligence.
The agent sits in Xcode’s sidebar where developers can use it to plan new features, implement them, and review the results. As developers work, the agent generates a transcript of its actions, which lets developers follow along and interact with it. For example, code snippets will appear in the sidebar that can be clicked to take developers directly to the spot in the file where the agent made a change. Code updates can also be simultaneously previewed.
So Xcode just builds entire apps without you now
Xcode’s Codex support will happily trundle away for half an hour sticking its tendrils into every little corner of your project, touching and changing every file. It’s certainly going to be fun to build new projects with, but ain’t no way in hell I want to let that loose on any of my existing apps 😂
Xcode 26.3 getting official Claude and Codex integration without the usual guardrails is interesting enough, but having MCP in the mix is… unusually open for Apple.
[…]
But at least they seem to have done their homework where it regards the in-editor agent harness–not sure how deep they went into IDE primitives (file graph, docs search, project settings), though, and the apparent lack of skills and other creature comforts that all the VS Code–based tools have is a bit of a bummer.
I don’t know if this is super-duper interesting news, but I think it’s super-duper interesting that Apple saw the need to release this now, not at WWDC in June.
They couldn’t even wait for the final version to be shipping before sending out the press release.
I presume Apple announced these integrations now, and not at WWDC, to capture some of the frenzy surrounding tools like Cursor and Copilot.
As a heads-up, it’s around this time of year that Xcode traditionally goes new-OS-only, i.e. requires macOS 26.
They haven’t done that with Xcode 26.3 just yet, but you might find that this is the last point release to run on Sequoia.
AI models can access more of Xcode’s features to work toward a project goal, and Apple worked directly with Anthropic and OpenAI to configure their agents for use in Xcode. Agents can create new files, examine the structure of a project in Xcode, build a project directly and run tests, take image snapshots to double-check work, and access full Apple developer documentation that has been designed for AI agents.
If you’re an developer for Apple’s platforms and were wondering where you rank in their list of priorities consider that they were apparently capable of writing docs and adding meaningful Xcode integrations all this time but they decided to do it to help AI models instead of you.
This repository contains system prompts and documentation from Xcode 26.3, providing insights into Apple’s approach to AI-assisted coding and comprehensive guides for iOS 26 features and frameworks.
Combine is officially dead. Quote from Xcode 26.3 AgentSystemPromptAddition:
Avoid using the Combine framework and instead prefer to use Swift’s async and await versions of APIs instead.
It’s still not officially deprecated, but it’s obviously not preferred for new development.
Previously:
- Codex App
- Apple LLM Generating SwiftUI
- Xcode 26.2
- What Xcode 26’s AI Chat Integration Is Missing
- How to Use Google Gemini in Xcode 26 Beta
- Claude Code Experience
- Swift Assist, Part Deux
- Xcode + Claude
- Tim, Don’t Kill My Vibe
- Whither Swift Assist?
- How to Use Cursor for iOS Development
- Xcode 16 Announced
- LLM Coding Tools in Xcode
Update (2026-02-05): Dimitri Bouniol:
512 GB is a rough starting SSD size for development… All I did is install Xcode, my usual git repos, and a few other apps, and I’m already at >50% used before anything iCloud has even been touched…
Apple has honed in their
config.tomlto supercharge iOS development. Notes on Liquid Glass, call outs for Foundation Models — the list goes on. Though Apple blasts the doors off of their “big” stuff at W.W.D.C., you’d be crazy to think they aren’t paying attention. How we develop software is changing, and internally, it’s clear they are humming along with it. The fact that Xcode 26.3 exists, right now, is proof. They didn’t just cut a new branch once Codex’s macOS app shipped.[…]
So, how is the actual experience? Well, pretty nice! This is such a tiny thing, but in Terminal — removing a chunk of text sucks. I’m sure there is some keyboard shortcut I’m missing, or some other app I could use like iTerm or what have you, but not being able to use
Command+Aand then delete it hurts. In Xcode, that’s easily done because the input is not longer running through Terminal, it’s just an AppKit text entry control.[…]
This is a fantastic start for Xcode. If you’re later to the Claude Code or Codex scene, this is a wonderful place to start. There’s simply no going back once you learn how to use these tools. Ideas that you wanted to hack on become doable, those dusty side project folders come alive a bit more, and you get ideas out of your head much faster.
I handed it the classic SameGame codebase, gave it my coding style markdown file, and said “So this is an old ObjC app for iOS. I would like you to completely convert it 1:1 to modern Swift, with the coding style in mind. Leave no ObjC behind”
No other prompts needed; I needed to update a few legacy things in the xcode project settings (min OS version, Swift version, etc), and got this[…] All automatic, not a line of ObjC remains. Deprecated APIs were all modernized. 5,400 lines of ObjC became 2900 lines of Swift 5.
I really hate to say it, but at least on a test project, this Xcode 26.3 coding agent stuff is pretty good. I can see why some are going gaga over it.
My main concern (other than copyright, which for some reason companies seem to ignore) is that it makes it to easy to just trust the generated code. You start reading things line by line and after a few minutes its hard not to skim over the suggested bits that get added.
Update (2026-02-06): Christian Tietze (Mastodon):
For example, ever wondered when to use the new
InlineArray? See Swift-InlineArray-Span.md[…][…]
That is a very good summary that is painfully absent on the InlineArray API docs. As a Swift veteran, you usually look for a Swift Evolution proposal for the new tech then an try to find out there what this is all about.
[…]
The collection also has docs for 3D charts,
VisualIntelligence(I didn’t know that framework existed!), and UIKit Liquid Glass guides andAttributedStringtutorials.These documents are probably not written by a human, or team of humans, because of inconsistent tone and all. So I’d wager they were LLM-generated themselves. I do hope they were edited for misinformation at least!
