diff --git a/lib/store.js b/lib/store.js
index 661b4b2..74c0932 100644
--- a/lib/store.js
+++ b/lib/store.js
@@ -45,4 +45,13 @@ function search(term) {
   return matches(load().notes, term);
 }
 
-module.exports = { all, add, remove, search, matches };
+function edit(id, newText) {
+  const data = load();
+  const note = data.notes.find(n => n.id === id);
+  if (!note) return null;
+  note.text = newText;
+  save(data);
+  return note;
+}
+
+module.exports = { all, add, remove, search, matches, edit };
diff --git a/notes.js b/notes.js
index df64a18..c0b128e 100644
--- a/notes.js
+++ b/notes.js
@@ -45,8 +45,24 @@ function main() {
       console.log(ok ? `Deleted note #${id}` : `No note #${id} found`);
       break;
     }
+    case "edit": {
+      const id = Number(rest[0]);
+      const text = rest.slice(1).join(" ").trim();
+      if (!id || !text) {
+        console.log("Usage: notes edit <id> <new text>");
+        return;
+      }
+      const note = store.edit(id, text);
+      console.log(note ? `Updated note #${id}: ${note.text}` : `No note #${id} found`);
+      break;
+    }
+    case "count": {
+      const total = store.all().length;
+      console.log(`You have ${total} note${total === 1 ? "" : "s"}.`);
+      break;
+    }
     default:
-      console.log("Commands: add <text> | list | search <term> | delete <id>");
+      console.log("Commands: add <text> | list | search <term> | delete <id> | edit <id> <new text> | count");
       console.log(`(Session locks after ${config.SESSION_TIMEOUT_MINUTES} minutes of inactivity.)`);
   }
 }
diff --git a/tests/notes.test.js b/tests/notes.test.js
index f0a31d8..7998baa 100644
--- a/tests/notes.test.js
+++ b/tests/notes.test.js
@@ -1,7 +1,20 @@
 const test = require("node:test");
 const assert = require("node:assert");
+const fs = require("fs");
+const path = require("path");
 
-const { matches } = require("../lib/store");
+const { matches, edit } = require("../lib/store");
+
+const NOTES_FILE = path.join(__dirname, "..", "notes.json");
+
+function withCleanStore(notes, fn) {
+  const prev = fs.existsSync(NOTES_FILE) ? fs.readFileSync(NOTES_FILE) : null;
+  const nextId = notes.length ? Math.max(...notes.map(n => n.id)) + 1 : 1;
+  fs.writeFileSync(NOTES_FILE, JSON.stringify({ nextId, notes }, null, 2));
+  try { return fn(); } finally {
+    prev ? fs.writeFileSync(NOTES_FILE, prev) : fs.unlinkSync(NOTES_FILE);
+  }
+}
 
 const notes = [
   { id: 1, text: "buy milk" },
@@ -24,3 +37,18 @@ test("search returns nothing when no note contains the term", () => {
   const result = matches(notes, "xyz");
   assert.strictEqual(result.length, 0);
 });
+
+test("edit updates the text of an existing note", () => {
+  withCleanStore([{ id: 1, text: "original" }], () => {
+    const updated = edit(1, "revised");
+    assert.strictEqual(updated.id, 1);
+    assert.strictEqual(updated.text, "revised");
+  });
+});
+
+test("edit returns null when the note id does not exist", () => {
+  withCleanStore([{ id: 1, text: "original" }], () => {
+    const result = edit(999, "revised");
+    assert.strictEqual(result, null);
+  });
+});