diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
new file mode 100644
index 00000000..8b694390
--- /dev/null
+++ b/implement-shell-tools/cat/cat.js
@@ -0,0 +1,38 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("cat command")
+  .description("create cat command")
+  .option("-n", "Number all lines")
+  .option("-b", "Number non-empty lines")
+  .argument("<paths...>", "File paths");
+
+program.parse();
+const paths = program.args;
+const number = program.opts().n;
+const nonEmptyLine = program.opts().b;
+
+let lineNumber = 1;
+
+for (const path of paths) {
+  try {
+    const read = await fs.readFile(path, "utf-8");
+    const lines = read.split("\n");
+
+    function printNumLine(line) {
+      console.log(`${String(lineNumber).padStart(6, " ")} ${line}`);
+      lineNumber++;
+    }
+
+    for (let i of lines) {
+      if (number || (nonEmptyLine && i.trim() !== "")) {
+        printNumLine(i);
+      } else {
+        console.log(i);
+      }
+    }
+  } catch (err) {
+    console.error(`File could not read: ${path}`);
+  }
+}
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
new file mode 100644
index 00000000..634fac12
--- /dev/null
+++ b/implement-shell-tools/ls/ls.js
@@ -0,0 +1,43 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("ls command")
+  .description("create ls command")
+  .option("-1", "One entry per line")
+  .option("-a", "Show all files including hidden")
+  .argument("[paths...]", "File paths");
+
+program.parse();
+
+const opts = program.opts();
+const paths = program.args.length > 0 ? program.args : ["."];
+const onePerLine = opts["1"];
+const showAll = opts.a;
+
+for (const targetPath of paths) {
+  try {
+    let files = await fs.readdir(targetPath);
+
+    if (!showAll) {
+      files = files.filter((f) => !f.startsWith("."));
+    }
+
+    
+    if (paths.length > 1) {
+      console.log(`${targetPath}:`);
+    }
+
+    if (onePerLine) {
+      for (const f of files) console.log(f);
+    } else {
+      console.log(files.join("  "));
+    }
+
+    if (paths.length > 1) {
+      console.log(); 
+    }
+  } catch (err) {
+    console.error(`ls: cannot access '${targetPath}': ${err.message}`);
+  }
+}
diff --git a/implement-shell-tools/package-lock.json b/implement-shell-tools/package-lock.json
new file mode 100644
index 00000000..38a22987
--- /dev/null
+++ b/implement-shell-tools/package-lock.json
@@ -0,0 +1,25 @@
+{
+  "name": "implement-shell-tools",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "implement-shell-tools",
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "commander": "^14.0.2"
+      }
+    },
+    "node_modules/commander": {
+      "version": "14.0.2",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-14.0.2.tgz",
+      "integrity": "sha512-TywoWNNRbhoD0BXs1P3ZEScW8W5iKrnbithIl0YH+uCmBd0QpPOA8yc82DS3BIE5Ma6FnBVUsJ7wVUDz4dvOWQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      }
+    }
+  }
+}
diff --git a/implement-shell-tools/package.json b/implement-shell-tools/package.json
new file mode 100644
index 00000000..e49468b7
--- /dev/null
+++ b/implement-shell-tools/package.json
@@ -0,0 +1,16 @@
+{
+  "name": "implement-shell-tools",
+  "version": "1.0.0",
+  "description": "Your task is to re-implement shell tools you have used.",
+  "main": "index.js",
+  "type": "module",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "commander": "^14.0.2"
+  }
+}
diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
new file mode 100644
index 00000000..9df12a1f
--- /dev/null
+++ b/implement-shell-tools/wc/wc.js
@@ -0,0 +1,54 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .option("-l", "Print only the line count")
+  .option("-w", "Print only the word count")
+  .option("-c", "Print only the byte count")
+  .argument("<paths...>", "One or more file paths");
+
+program.parse();
+
+const opts = program.opts();
+const paths = program.args;
+
+async function wcFile(path) {
+  const content = await fs.readFile(path, "utf8");
+
+  const lines = content.split("\n").length;
+  const words = content.trim().split(/\s+/).filter(Boolean).length;
+  const bytes = Buffer.byteLength(content, "utf8");
+
+  return { lines, words, bytes };
+}
+
+function formatOutput(counts, filename, opts) {
+  if (opts.l) return `${counts.lines} ${filename}`;
+  if (opts.w) return `${counts.words} ${filename}`;
+  if (opts.c) return `${counts.bytes} ${filename}`;
+
+  return `${String(counts.lines).padStart(8)} ${String(counts.words).padStart(
+    8
+  )} ${String(counts.bytes).padStart(8)} ${filename}`;
+}
+
+async function main() {
+  let total = { lines: 0, words: 0, bytes: 0 };
+  let multipleFiles = paths.length > 1;
+
+  for (const path of paths) {
+    const counts = await wcFile(path);
+
+    total.lines += counts.lines;
+    total.words += counts.words;
+    total.bytes += counts.bytes;
+
+    console.log(formatOutput(counts, path, opts));
+  }
+
+  if (multipleFiles) {
+    console.log(formatOutput(total, "total", opts));
+  }
+}
+
+main();