Making project references

I am trying to recreate a React-Native project with XcodeGen, and I must admit that it feels like a "one step forward, two steps back" kind of deal to understand xcode project files.

But, I have come to understand, from looking at the project file I have, that I need to make some "projectReferences", but I can't seem to figure out how to spec that.

In the project file I have, the section looks something like this:

projectReferences = (
				{
					ProductGroup = 00C302A81ABCB8CE00DB3ED1 /* Products */;
					ProjectRef = 00C302A71ABCB8CE00DB3ED1 /* RCTActionSheet.xcodeproj */;
				},
				{
					ProductGroup = 5E91572E1DD0AC6500FF2AA8 /* Products */;
					ProjectRef = 5E91572D1DD0AC6500FF2AA8 /* RCTAnimation.xcodeproj */;
				},

/* Begin PBXGroup section */
		00C302A81ABCB8CE00DB3ED1 /* Products */ = {
			isa = PBXGroup;
			children = (
				00C302AC1ABCB8CE00DB3ED1 /* libRCTActionSheet.a */,
			);
			name = Products;
			sourceTree = "<group>";
		};

		00C302A71ABCB8CE00DB3ED1 /* RCTActionSheet.xcodeproj */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.pb-project"; name = RCTActionSheet.xcodeproj; path = "../node_modules/react-native/Libraries/ActionSheetIOS/RCTActionSheet.xcodeproj"; sourceTree = "<group>"; };

Is this possible to do? Or am I misunderstanding something?

Start by tracing how XcodeGen represents external Xcode projects in its project specification, then compare generated output with the projectReferences, PBXGroup, and PBXFileReference snippets shown here. Done means a project specification can express these references and generation produces the corresponding project entries.