diff --git a/src/expand.ts b/src/expand.ts
index 61e48b9..6cc654f 100644
--- a/src/expand.ts
+++ b/src/expand.ts
@@ -27,3 +27,10 @@ export function appendSuffix(block: string, suffix: string | undefined): string
 	}
 	return `${block}\n\n${trimmed}`;
 }
+
+/** Read SKILL.md and format full user message text for re-inject (SPEC §5.3). */
+export function expandSkill(meta: SkillBlockMeta, suffix?: string): string {
+	const body = readSkillBody(meta.filePath);
+	const block = formatBlock(meta, body);
+	return appendSuffix(block, suffix);
+}