Apple Seeds Xcode 26.3 RC 2 With Claude 4.6 Support [Download]

Apple today seeded a second Release Candidate of Xcode 26.3 to developers, build 17C528. The update arrives just over two weeks after RC 1 was released on February 3 and includes Swift 6.2.3 alongside SDKs for iOS 26.2, iPadOS 26.2, macOS 26.2, tvOS 26.2, and visionOS 26.2. Xcode 26.3 RC 2 also supports on-device debugging in iOS 15 and later, tvOS 15 and later, watchOS 8 and later, and visionOS.



The primary focus of Xcode 26.3 is the introduction of agentic coding. This feature allows Xcode to work autonomously toward specific development goals by breaking down tasks, making decisions based on project architecture, and utilizing built-in tools. It is powered by deep integrations with Anthropic's Claude Agent and OpenAI's Codex, while also supporting the open Model Context Protocol (MCP) to let developers bring in other compatible agents. To manage these new capabilities, Apple introduced a permissions system that gives developers fine-grained control over what external tools can access within their environment.


This second Release Candidate resolves several bugs found in earlier builds and updates the underlying agent integrations. Apple has officially added support for Anthropic's recently launched Claude 4.6 and upgraded the Codex integration to version 0.98.0 for improved stability. The release also fixes issues where custom model providers would disappear between app launches, resolves a crash related to the "Generate a Fix" button in the Issues Navigator, ensures that externally configured MCP servers are no longer overwritten during Codex initialization, and addresses additional problems involving agent-run code snippets, conversation history restore, and tool execution behavior.

Apple notes a few lingering issues that developers should keep an eye on. Denying Claude or Codex access to a project located in privacy-protected directories such as Desktop, Downloads, or Documents will permanently block the agent from that folder unless permissions are adjusted in macOS System Settings or the project is moved elsewhere. Additionally, pasting files directly into the coding assistant interface does not consistently send their contents to the active agent, certain conversation history actions may not function as expected, and some agent settings may require restarting Xcode to take effect.

Developers can download Xcode 26.3 RC 2 directly from the Apple Developer Center. The software requires a Mac running macOS Sequoia 15.6 or later.

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