Composition
Composition is how a skill version resolves ordered prompt attachments into the rendered message list for the model.
Prompts are reusable authored objects. Prompt versions hold immutable content. Skill versions expose promptComposition, which records the prompt references, attachment mode, resolved version metadata, and order used for preview and runs.
Trace
Preview and run detail expose composition trace data in skillVersionSchema.preview and in contract trace sections on runs.