diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7fa55f2..ca3d662 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 # 3.23.0
 
-- 【feat】支持外部调用 `getInitialAndFinal`、`getFinalParts`、`getNumOfTone` 等 API
+- 【feat】支持外部调用 `getInitialAndFinal`、`getFinalParts`、`getNumOfTone` 等 API [#255](https://github.com/zh-lx/pinyin-pro/pull/255)
 
 # 3.22.2
 
diff --git a/test/external-api.test.js b/test/external-api.test.js
new file mode 100644
index 0000000..57c8fa5
--- /dev/null
+++ b/test/external-api.test.js
@@ -0,0 +1,26 @@
+import { getInitialAndFinal, getFinalParts, getNumOfTone } from "../lib/index";
+import { expect, describe, it } from "vitest";
+
+describe("final", () => {
+  it("[external]initial and final", () => {
+    const result = getInitialAndFinal("guang");
+    expect(result).to.deep.equal({
+      final: "uang",
+      initial: "g",
+    });
+  });
+
+  it("[external]getFinalParts", () => {
+    const result = getFinalParts("guang");
+    expect(result).to.deep.equal({
+      body: "a",
+      head: "u",
+      tail: "ng",
+    });
+  });
+
+  it("[external]getNumOfTone", () => {
+    const result = getNumOfTone("hàn yǔ pīn yīn");
+    expect(result).to.deep.equal("4 3 1 1");
+  });
+});