diff --git a/src/core/pm.ts b/src/core/pm.ts
new file mode 100644
index 0000000..bf32cc8
--- /dev/null
+++ b/src/core/pm.ts
@@ -0,0 +1,58 @@
+import type { RuneConfig } from "../types.ts";
+
+export const DEFAULT_PREFIX = "bunx @lanyuanxiaoyao/rune";
+
+export function inferFromEnvironment(
+  execPath: string,
+  userAgent: string | undefined,
+): string | null {
+  if (execPath.includes("bun")) return "bunx @lanyuanxiaoyao/rune";
+  if (userAgent?.includes("pnpm")) return "pnpx @lanyuanxiaoyao/rune";
+  if (userAgent?.includes("npm")) return "npx @lanyuanxiaoyao/rune";
+  return null;
+}
+
+export async function checkCommandAvailable(command: string): Promise<boolean> {
+  const which = process.platform === "win32" ? "where" : "which";
+  try {
+    const proc = Bun.spawn([which, command], {
+      stdout: "ignore",
+      stderr: "ignore",
+    });
+    const exitCode = await proc.exited;
+    return exitCode === 0;
+  } catch {
+    return false;
+  }
+}
+
+export async function detectCommandPrefix(): Promise<string | null> {
+  if (await checkCommandAvailable("rune")) return "rune";
+
+  const inferred = inferFromEnvironment(process.execPath, process.env.npm_config_user_agent);
+  if (inferred) return inferred;
+
+  for (const pm of ["bunx", "pnpx", "npx"]) {
+    if (await checkCommandAvailable(pm)) return `${pm} @lanyuanxiaoyao/rune`;
+  }
+
+  return null;
+}
+
+export function getPmPrefix(config?: RuneConfig): string {
+  return config?.metadata?.command ?? DEFAULT_PREFIX;
+}
+
+export function getFallbackNote(): string {
+  return `如果没有安装 bun，可使用 \`pnpx @lanyuanxiaoyao/rune\` 或 \`npx @lanyuanxiaoyao/rune\` 替代`;
+}
+
+export function applyCommandPrefix(text: string, config?: RuneConfig): string {
+  const prefix = getPmPrefix(config);
+  const hasCommand = /\brune(?=\s)/.test(text);
+  const result = text.replace(/\brune(?=\s)/g, prefix);
+  if (!config?.metadata?.command && hasCommand) {
+    return result + "\n\n" + getFallbackNote();
+  }
+  return result;
+}
diff --git a/src/types.ts b/src/types.ts
index e5f62dc..a6af50b 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -36,6 +36,9 @@ export interface StagesConfig {
 
 export interface RuneConfig {
   stages: StagesConfig;
+  metadata?: {
+    command?: string;
+  };
 }
 
 export interface TaskItem {
diff --git a/tests/core/pm.test.ts b/tests/core/pm.test.ts
new file mode 100644
index 0000000..3e0374c
--- /dev/null
+++ b/tests/core/pm.test.ts
@@ -0,0 +1,112 @@
+import { describe, it, expect } from "bun:test";
+import {
+  inferFromEnvironment,
+  getPmPrefix,
+  DEFAULT_PREFIX,
+  getFallbackNote,
+  applyCommandPrefix,
+} from "../../src/core/pm.ts";
+import type { RuneConfig } from "../../src/types.ts";
+
+describe("inferFromEnvironment", () => {
+  it("execPath 包含 bun 时返回 bunx 前缀", () => {
+    const result = inferFromEnvironment("/home/user/.bun/bin/bun", undefined);
+    expect(result).toBe("bunx @lanyuanxiaoyao/rune");
+  });
+
+  it("npm_config_user_agent 包含 pnpm 时返回 pnpx 前缀", () => {
+    const result = inferFromEnvironment("/usr/bin/node", "pnpm/9.0.0");
+    expect(result).toBe("pnpx @lanyuanxiaoyao/rune");
+  });
+
+  it("npm_config_user_agent 包含 npm 时返回 npx 前缀", () => {
+    const result = inferFromEnvironment("/usr/bin/node", "npm/10.0.0");
+    expect(result).toBe("npx @lanyuanxiaoyao/rune");
+  });
+
+  it("pnpm 优先于 npm（userAgent 同时包含两者时）", () => {
+    const result = inferFromEnvironment("/usr/bin/node", "pnpm/9.0.0 npm/10.0.0");
+    expect(result).toBe("pnpx @lanyuanxiaoyao/rune");
+  });
+
+  it("无法推断时返回 null", () => {
+    const result = inferFromEnvironment("/usr/bin/node", undefined);
+    expect(result).toBeNull();
+  });
+});
+
+describe("getPmPrefix", () => {
+  it("有配置时返回 config.metadata.command", () => {
+    const config: RuneConfig = {
+      stages: {},
+      metadata: { command: "rune" },
+    };
+    expect(getPmPrefix(config)).toBe("rune");
+  });
+
+  it("配置中无 metadata 时返回默认前缀", () => {
+    const config: RuneConfig = { stages: {} };
+    expect(getPmPrefix(config)).toBe(DEFAULT_PREFIX);
+  });
+
+  it("不传配置时返回默认前缀", () => {
+    expect(getPmPrefix()).toBe(DEFAULT_PREFIX);
+    expect(getPmPrefix(undefined)).toBe("bunx @lanyuanxiaoyao/rune");
+  });
+});
+
+describe("getFallbackNote", () => {
+  it("返回降级说明文本", () => {
+    const note = getFallbackNote();
+    expect(note).toContain("pnpx @lanyuanxiaoyao/rune");
+    expect(note).toContain("npx @lanyuanxiaoyao/rune");
+  });
+});
+
+describe("applyCommandPrefix", () => {
+  it("有配置时替换 rune 为配置前缀", () => {
+    const config: RuneConfig = {
+      stages: {},
+      metadata: { command: "rune" },
+    };
+    const result = applyCommandPrefix("执行 rune status 查看", config);
+    expect(result).toBe("执行 rune status 查看");
+  });
+
+  it("无配置时替换为默认前缀", () => {
+    const result = applyCommandPrefix("执行 rune status 查看", undefined);
+    expect(result).toContain("bunx @lanyuanxiaoyao/rune status");
+    expect(result).not.toContain("执行 rune status");
+  });
+
+  it("无配置且文本含命令时追加降级说明", () => {
+    const result = applyCommandPrefix("执行 rune status 查看", undefined);
+    expect(result).toContain("pnpx @lanyuanxiaoyao/rune");
+    expect(result).toContain("如果没有安装 bun");
+  });
+
+  it("有配置时不追加降级说明", () => {
+    const config: RuneConfig = {
+      stages: {},
+      metadata: { command: "bunx @lanyuanxiaoyao/rune" },
+    };
+    const result = applyCommandPrefix("执行 rune status 查看", config);
+    expect(result).not.toContain("如果没有安装 bun");
+  });
+
+  it("不替换 /rune- 形式（编辑器斜杠命令）", () => {
+    const text = "使用 /rune-plan 进入规划阶段，然后 rune build 开始构建";
+    const config: RuneConfig = {
+      stages: {},
+      metadata: { command: "bunx @lanyuanxiaoyao/rune" },
+    };
+    const result = applyCommandPrefix(text, config);
+    expect(result).toContain("/rune-plan");
+    expect(result).toContain("bunx @lanyuanxiaoyao/rune build");
+  });
+
+  it("文本不含 rune 命令时无配置也不追加降级说明", () => {
+    const result = applyCommandPrefix("纯文本无命令", undefined);
+    expect(result).toBe("纯文本无命令");
+  });
+});