Visual overview

Use the workflow to follow the task, and the architecture map to separate responsibilities. These are conceptual maps; the guide below defines implementation details and verification limits.

01 / WorkflowFrom intent to a checked result
  1. Identify the configuration file
  2. Validate syntax without conversion
  3. Resolve targets in compatible Xcode
  4. Record preview destination and evidence
02 / ArchitectureResponsibility boundaries
  1. Boundary 1Xcode project bundle
  2. Boundary 2JSON or legacy configuration
  3. Boundary 3Read-only analysis boundary

Connected responsibilities, not a required class hierarchy or an execution trace.

Context

Rechecked 2026-09-29 (beta 2) against Apple’s release notes and project-format guide. This is beta documentation, not a local Xcode 27.2 execution result.

Pattern

The .xcodeproj bundle remains. Its internal project configuration can use JSON with an .xcproj extension instead of the older .pbxproj property list. Apple says Xcode 27 and later can open either format; Xcode 27.2 makes JSON the default for new configurations. Existing projects can switch through the File inspector’s Project Format control. Review both the removed file and the added file in Git.

Our project analysis recognizes both configuration files and checks JSON syntax. It does not resolve the new target/build-setting schema or write conversions. Release preparation stays blocked for JSON projects; launch review reports an explicit coverage limitation. When both formats coexist, it does not silently choose the legacy file. Use compatible Xcode to resolve the project before making claims about target membership, deployment settings, or launch assets.

For Apple’s RenderPreview MCP tool, inspect the available render destinations returned by the installed tool and select the intended one using its advertised schema. Record the destination with preview evidence. Don’t hardcode guessed argument names or treat a preview as a Simulator test.

Apple directs Duo development to Xcode 27.1 beta, even from the 27.2 notes. See docs/platforms/iphone-duo.md and docs/tooling/device-hub.md.

Anti-Patterns

  • Do not rename the outer bundle to .xcproj.
  • Do not feed JSON to the OpenStep plist parser, infer its schema from .pbxproj, or claim that valid JSON proves a buildable project.
  • Do not change the selected Xcode or migrate user projects without a scoped request.

Verification

Synthetic regression tests cover discovery, malformed JSON, unsupported JSON roots, workspace selection and coexisting formats. The earlier verification used Xcode 26.6; Xcode 27.0 is now installed, but real JSON project builds and Xcode 27.2 preview sessions remain unverified.

Beta 2 follow-up

Apple adds GetCodeCoverage to its coding-assistant MCP tools. Discover its installed schema before requesting the latest test coverage, optionally scoped to a target or file. This is Apple's tool, not a new ios-agent-mcp tool. The preview override picker also gains alternative-display selection.

Known issues include temporary black Duo captures after boot, simulator-clone permissions, and reinstalled runtimes remaining unavailable. Avoid diagnosing those immediately as app defects. Apple's service-restart workaround is disruptive; obtain authorization before interrupting active simulators. For iOS 27.1-specific APIs in Catalyst, Apple recommends platform compilation conditionals. The non-iOS SDKs incorrectly advertising deployment target 27.1 need extra scrutiny. None of these beta 2 behaviors was exercised on the local Xcode 27.0 installation.