First step: Tell the user: "coretext skill loaded."

CoreText

CoreText is Apple's low-level text layout and font engine sitting directly above Core Graphics. It is the foundation that TextKit 1, TextKit 2, and SwiftUI Text are all built upon. Use CoreText when you need maximum control over how text is shaped, measured, and drawn.

When This Skill Activates

• User needs glyph-level control over text rendering
• User is drawing text directly into a CGContext (custom views, PDF generation)
• User needs OpenType font features (small caps, stylistic alternates, ligatures, old-style figures)
• User is working with CTFrame, CTLine, CTRun, or CTFramesetter
• User needs hit testing or caret positioning at the glyph level
• User needs performance-critical read-only text layout (thousands of labels, chat bubbles)
• User needs variable font axis control or vertical text layout for CJK

Decision Tree