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..c901b258f
--- /dev/null
+++ b/implement-shell-tools/ls/ls.js
@@ -0,0 +1,32 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const args = process.argv.slice(2);
+
+let showAll = false;
+let path = ".";
+
+
+for (const arg of args) {
+  if (arg === "-a") {
+    showAll = true;
+  } else if (arg === "-1") {
+    // do nothing: already printing one file per line
+    path = arg;
+  }
+}
+
+
+const files = await fs.readdir(path);
+
+for (const file of files) {
+
+  if (!showAll && file.startsWith(".")) {
+    continue;
+  }
+
+  console.log(file);
+}
+
+// We already print one file per line because 
+// console.log(file) automatically puts each file on its own line.
\ No newline at end of file
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