diff --git a/.changeset/heavy-cameras-nail.md b/.changeset/heavy-cameras-nail.md
new file mode 100644
index 0000000..91a04fc
--- /dev/null
+++ b/.changeset/heavy-cameras-nail.md
@@ -0,0 +1,5 @@
+---
+'@xstools/utility': patch
+---
+
+add internal utilities
diff --git a/packages/utility/src/_internal/index.ts b/packages/utility/src/_internal/index.ts
new file mode 100644
index 0000000..5618975
--- /dev/null
+++ b/packages/utility/src/_internal/index.ts
@@ -0,0 +1,3 @@
+export * from './pathToSegments';
+export * from './stub';
+export * from './toArgs';
diff --git a/packages/utility/src/_internal/pathToSegments.spec.ts b/packages/utility/src/_internal/pathToSegments.spec.ts
new file mode 100644
index 0000000..2aceff4
--- /dev/null
+++ b/packages/utility/src/_internal/pathToSegments.spec.ts
@@ -0,0 +1,42 @@
+import { describe, expect, test } from 'bun:test';
+import { pathToSegments } from './pathToSegments';
+
+describe('pathToSegments', () => {
+  test('normal usage', () => {
+    expect(pathToSegments('a.b.c')).toEqual(['a', 'b', 'c']);
+    expect(pathToSegments('a[b][c]')).toEqual(['a', 'b', 'c']);
+    expect(pathToSegments('a[b].c')).toEqual(['a', 'b', 'c']);
+    expect(pathToSegments('a["b.c"].d')).toEqual(['a', 'b.c', 'd']);
+    expect(pathToSegments('.a.b.c')).toEqual(['', 'a', 'b', 'c']);
+  });
+
+  test('empty', () => {
+    expect(pathToSegments('')).toEqual([]);
+    expect(pathToSegments('.')).toEqual(['', '']);
+    expect(pathToSegments('[]')).toEqual(['']);
+    expect(pathToSegments('a[].b')).toEqual(['a', '', 'b']);
+  });
+
+  test('one path', () => {
+    expect(pathToSegments('a')).toEqual(['a']);
+    expect(pathToSegments('[a]')).toEqual(['a']);
+    expect(pathToSegments('[a.b]')).toEqual(['a.b']);
+    expect(pathToSegments('["a.b"]')).toEqual(['a.b']);
+    expect(pathToSegments('"[a.b]"')).toEqual(['"', 'a.b', '"']);
+  });
+
+  test('complex', () => {
+    expect(pathToSegments('a[-1.23]["[\\"b\\"]"].c[\'[\\\'d\\\']\'][\ne\n][f].g')).toEqual([
+      'a',
+      '-1.23',
+      '["b"]',
+      'c',
+      "['d']",
+      '\ne\n',
+      'f',
+      'g',
+    ]);
+
+    expect(pathToSegments('.a[b].c.d[e]["f.g"].h')).toEqual(['', 'a', 'b', 'c', 'd', 'e', 'f.g', 'h']);
+  });
+});
diff --git a/packages/utility/src/_internal/pathToSegments.ts b/packages/utility/src/_internal/pathToSegments.ts
new file mode 100644
index 0000000..18c9b34
--- /dev/null
+++ b/packages/utility/src/_internal/pathToSegments.ts
@@ -0,0 +1,65 @@
+/**
+ * Converts a deep key string into an array of path segments.
+ *
+ * References: https://github.com/toss/es-toolkit/blob/main/src/compat/_internal/toPath.ts
+ *
+ * @example
+ * toSegments('') // => []
+ * toSegments('a.b.c') // => ['a', 'b', 'c']
+ * toSegments('a[b][c]') // => ['a', 'b', 'c']
+ * toSegments('.a.b.c') // => ['', 'a', 'b', 'c']
+ * toSegments('a["b.c"].d') // => ['a', 'b.c', 'd']
+ * toSegments('.a[b].c.d[e]["f.g"].h') // => ['', 'a', 'b', 'c', 'd', 'e', 'f.g', 'h']
+ */
+export function pathToSegments(deepKey: string): string[] {
+  const ESCAPE_REGEXP = /\\(\\)?/g;
+  const PROPERTY_REGEXP = RegExp(
+    // Match anything that isn't a dot or bracket.
+    '[^.[\\]]+' +
+      '|' +
+      // Or match property names within brackets.
+      '\\[(?:' +
+      // Match a non-string expression.
+      '([^"\'][^[]*)' +
+      '|' +
+      // Or match strings (supports escaping characters).
+      '(["\'])((?:(?!\\2)[^\\\\]|\\\\.)*?)\\2' +
+      ')\\]' +
+      '|' +
+      // Or match "" as the space between consecutive dots or empty brackets.
+      '(?=(?:\\.|\\[\\])(?:\\.|\\[\\]|$))',
+    'g',
+  );
+
+  const result: string[] = [];
+
+  if (deepKey[0] === '.') {
+    result.push('');
+  }
+
+  let match: RegExpExecArray | null;
+  let lastIndex = 0;
+
+  while ((match = PROPERTY_REGEXP.exec(deepKey)) !== null) {
+    let key = match[0];
+    const expr = match[1];
+    const quote = match[2];
+    const substr = match[3];
+
+    if (quote && substr) {
+      key = substr.replace(ESCAPE_REGEXP, '$1');
+    } else if (expr) {
+      key = expr;
+    }
+
+    result.push(key);
+
+    if (PROPERTY_REGEXP.lastIndex === lastIndex) {
+      PROPERTY_REGEXP.lastIndex++;
+    } else {
+      lastIndex = PROPERTY_REGEXP.lastIndex;
+    }
+  }
+
+  return result;
+}
diff --git a/packages/utility/src/_internal/stub.ts b/packages/utility/src/_internal/stub.ts
new file mode 100644
index 0000000..c821867
--- /dev/null
+++ b/packages/utility/src/_internal/stub.ts
@@ -0,0 +1,15 @@
+import { toArgs } from './toArgs';
+
+export const stubTrue = (): true => {
+  return true;
+};
+
+export const stubFalse = (): false => {
+  return false;
+};
+
+export const stubZero = (): number => {
+  return 0;
+};
+
+export const stubArgs = toArgs([1, 2, 3]);
diff --git a/packages/utility/src/_internal/toArgs.spec.ts b/packages/utility/src/_internal/toArgs.spec.ts
new file mode 100644
index 0000000..71ad2eb
--- /dev/null
+++ b/packages/utility/src/_internal/toArgs.spec.ts
@@ -0,0 +1,14 @@
+import { describe, expect, test } from 'bun:test';
+import { toArgs } from './toArgs';
+
+describe('toArgs', () => {
+  test('converts an array to an arguments object', () => {
+    const result = toArgs([1, 2, 3]);
+
+    expect(result.toString()).toBe('[object Arguments]');
+
+    (function (..._args) {
+      expect(arguments).toEqual(result);
+    })(1, 2, 3);
+  });
+});
diff --git a/packages/utility/src/_internal/toArgs.ts b/packages/utility/src/_internal/toArgs.ts
new file mode 100644
index 0000000..5c307c4
--- /dev/null
+++ b/packages/utility/src/_internal/toArgs.ts
@@ -0,0 +1,11 @@
+/**
+ * Converts an array to an `arguments` object.
+ *
+ * @example
+ * toArgs([1, 2, 3]); // { '0': 1, '1': 2, '2': 3 } as IArguments
+ */
+export const toArgs = (arr: unknown[]): IArguments => {
+  return (function (..._: unknown[]) {
+    return arguments;
+  })(...arr);
+};