diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
new file mode 100644
index 000000000..0563a28fa
--- /dev/null
+++ b/implement-shell-tools/cat/cat.js
@@ -0,0 +1,54 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const args = process.argv.slice(2);
+
+let option = "none";
+const paths = [];
+
+
+for (const arg of args) {
+  if (arg === "-n") {
+    option = "n";
+  } else if (arg === "-b") {
+    option = "b";
+  } else {
+    paths.push(arg);
+  }
+}
+
+if (paths.length === 0) {
+  console.error("Expected at least one file path.");
+  process.exit(1);
+}
+
+for (const path of paths) {
+  const content = await fs.readFile(path, "utf-8");
+
+  const lines = content.split("\n");
+
+  let lineNumber = 1;
+
+  for (const line of lines) {
+
+    if (option === "n") {
+      console.log(`${lineNumber} ${line}`);
+      lineNumber++;
+    }
+
+    else if (option === "b") {
+
+      if (line !== "") {
+        console.log(`${lineNumber} ${line}`);
+        lineNumber++;
+      } else {
+        console.log("");
+      }
+
+    }
+
+    else {
+      console.log(line);
+    }
+  }
+}
\ No newline at end of file
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
new file mode 100644
index 000000000..d7b1efe73
--- /dev/null
+++ b/implement-shell-tools/ls/ls.js
@@ -0,0 +1,28 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("ls")
+  .description("List directory contents")
+  .option("-a, --all", "show hidden files")
+  .option("-1, --one-per-line", "display one file per line")
+  .argument("[path]", "directory to list", ".");
+
+program.parse();
+
+const options = program.opts();
+const path = program.args[0] || ".";
+
+const files = await fs.readdir(path);
+
+const filteredFiles = files.filter((file) => {
+  return options.all || !file.startsWith(".");
+});
+
+if (options.onePerLine) {
+  for (const file of filteredFiles) {
+    console.log(file);
+  }
+} else {
+  console.log(filteredFiles.join(" "));
+}
\ No newline at end of file
diff --git a/implement-shell-tools/package-lock.json b/implement-shell-tools/package-lock.json
new file mode 100644
index 000000000..0bdcfb87e
--- /dev/null
+++ b/implement-shell-tools/package-lock.json
@@ -0,0 +1,21 @@
+{
+  "name": "implement-shell-tools",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "commander": "^15.0.0"
+      }
+    },
+    "node_modules/commander": {
+      "version": "15.0.0",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-15.0.0.tgz",
+      "integrity": "sha512-z67u4ZhzCL/Tydu1lJARtEZYWbWaN7oYLHbsuzocr6y4N6WZAagG3RQ4FW61V1/0+jImpj293XfrcYnd1qxtPg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=22.12.0"
+      }
+    }
+  }
+}
diff --git a/implement-shell-tools/package.json b/implement-shell-tools/package.json
new file mode 100644
index 000000000..c85f233e0
--- /dev/null
+++ b/implement-shell-tools/package.json
@@ -0,0 +1,17 @@
+{
+  "dependencies": {
+    "commander": "^15.0.0"
+  },
+  "name": "implement-shell-tools",
+  "version": "1.0.0",
+  "description": "Your task is to re-implement shell tools you have used.",
+  "main": "index.js",
+  "devDependencies": {},
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "type": "module"
+}
diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
new file mode 100644
index 000000000..a57901653
--- /dev/null
+++ b/implement-shell-tools/wc/wc.js
@@ -0,0 +1,44 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const args = process.argv.slice(2);
+
+let countLines = false;
+let countWords = false;
+let countChars = false;
+const paths = [];
+
+// parse args
+for (const arg of args) {
+  if (arg === "-l") countLines = true;
+  else if (arg === "-w") countWords = true;
+  else if (arg === "-c") countChars = true;
+  else paths.push(arg);
+}
+
+if (paths.length === 0) {
+  console.error("Please provide at least one file");
+  process.exit(1);
+}
+
+for (const path of paths) {
+  const content = await fs.readFile(path, "utf-8");
+
+  const lines = content.split("\n").length;
+  const words = content.trim().split(/\s+/).length;
+  const chars = content.length;
+
+  // if no flags → show all
+  if (!countLines && !countWords && !countChars) {
+    console.log(lines, words, chars, path);
+    continue;
+  }
+
+  const output = [];
+
+  if (countLines) output.push(lines);
+  if (countWords) output.push(words);
+  if (countChars) output.push(chars);
+
+  console.log(...output, path);
+}
\ No newline at end of file