diff --git a/src/core/assembler.ts b/src/core/assembler.ts
index 50e8152..b554a00 100644
--- a/src/core/assembler.ts
+++ b/src/core/assembler.ts
@@ -106,23 +106,22 @@ export async function assembleTaskPrompt(
     });
   }
 
-  const parts: string[] = [];
-  parts.push(`# 任务拆解阶段：${changeName}\n`);
-  parts.push(task.prompt);
+  const builder = new PromptBuilder();
+
+  builder.head(`# 任务拆解阶段：${changeName}`);
+  builder.prompt(task.prompt);
 
   const planDocPaths = plan.documents.map((d) => join(changeDir, `${d.name}.md`));
-  parts.push(`\n请先读取以下规划文档：`);
-  for (const p of planDocPaths) {
-    parts.push(`- ${p}`);
-  }
+  builder.context(`请先读取以下规划文档：\n${planDocPaths.map((p) => `- ${p}`).join("\n")}`);
 
   const taskPath = join(changeDir, "task.md");
   if (existsSync(taskPath)) {
-    parts.push(`\ntask.md 已存在，请先读取 ${taskPath} 查看已有内容，在此基础上修订。`);
+    builder.context(`task.md 已存在，请先读取 ${taskPath} 查看已有内容，在此基础上修订。`);
   }
 
-  parts.push(`\n请将任务列表写入 ${taskPath}`);
-  return applyCommandPrefix(parts.join("\n"), config);
+  builder.guide(`请将任务列表写入 ${taskPath}`);
+
+  return applyCommandPrefix(builder.build(), config);
 }
 
 export async function assembleBuildPrompt(
@@ -168,14 +167,16 @@ export async function assembleBuildPrompt(
     return `所有任务已完成。变更 "${changeName}" 可以归档。`;
   }
 
-  const parts: string[] = [];
-  parts.push(`# 构建阶段：${changeName}\n`);
-  parts.push(build.prompt);
-  parts.push(`\n请先读取 ${taskPath} 查看任务列表。`);
-  parts.push(`当前有 ${pendingTasks.length} 个待执行任务，从第一个未完成的任务开始。`);
-  parts.push(`完成后更新 ${taskPath} 中的 checkbox。`);
+  const builder = new PromptBuilder();
 
-  return applyCommandPrefix(parts.join("\n"), config);
+  builder.head(`# 构建阶段：${changeName}`);
+  builder.prompt(build.prompt);
+  builder.context(
+    `请先读取 ${taskPath} 查看任务列表。\n当前有 ${pendingTasks.length} 个待执行任务，从第一个未完成的任务开始。`,
+  );
+  builder.guide(`完成后更新 ${taskPath} 中的 checkbox。`);
+
+  return applyCommandPrefix(builder.build(), config);
 }
 
 export async function assembleArchivePrompt(