Xcode 27.2 introduces a new on-disk format for .xcodeproj bundles: a JSON5 file called project.xcproj that replaces the classic OpenStep project.pbxproj. The format is documented at apple/xcode-project-format, and while it's still marked experimental, it already delivers what most teams have been asking for from .pbxproj for years: smaller, more readable diffs and far fewer merge conflicts.
Tuist now lets you opt into it from your Tuist.swift:
import ProjectDescription
let tuist = Tuist(
project: .tuist(
generationOptions: .options(
projectFormat: .xcproj
)
)
)
Every .xcodeproj Tuist generates for that workspace will be written as project.xcproj. The default stays .pbxproj, so nothing changes until you flip the option.
Because the format is still experimental in Xcode itself, you should treat this as an opt in for teams that are already on Xcode 27.2 across local development and CI. Earlier Xcode versions cannot read project.xcproj, so make sure every machine that opens the workspace, including runners, is on 27.2 or later before you turn it on.