diff --git a/src/commands/add/dep.ts b/src/commands/add/dep.ts
new file mode 100644
index 0000000..8bf6b7d
--- /dev/null
+++ b/src/commands/add/dep.ts
@@ -0,0 +1,44 @@
+// import {flags} from '@oclif/command'
+import { BaseCommand } from '../../utls/base-command';
+import { BaseAddCommand } from '../../utls/base-add-command';
+import { flags } from '@oclif/command';
+
+export default class Dep extends BaseAddCommand {
+  static description = 'proxy to yarn add, plus gitmoji commit';
+
+  static examples = [
+    `$ nbx add:dep -D eslint`,
+    `$ nbx add:dep --dev eslint`,
+    `$ nbx add:dep chalk`,
+  ];
+
+  static flags = {
+    ...BaseCommand.flags,
+    dev: flags.boolean({ default: false, char: 'D', description: 'install as a dev dependency' }),
+  };
+
+  static args = [{ name: 'dep', description: 'The dependency to install', required: true }];
+
+  async run() {
+    if (!this.hasDirPackageJson()) {
+      this.error('There is no package.json not found in the current folder');
+    }
+    const {
+      args: { dep },
+      flags: { dev },
+    } = this.parse(Dep);
+
+    if ((dev && this.hasDevDependencyInPackageJson(dep)) || this.hasDependencyInPackageJson(dep)) {
+      if (this.hasDevDependencyInPackageJson(dep)) {
+        this.error(`${dep} is already installed in this project.`);
+      }
+    }
+
+    await this.initGit();
+    if (dev) {
+      await this.addDevDependency(dep, true);
+    } else {
+      await this.addDependency(dep, true);
+    }
+  }
+}
diff --git a/src/tests/add/__snapshots__/dep.spec.ts.snap b/src/tests/add/__snapshots__/dep.spec.ts.snap
new file mode 100644
index 0000000..86d4335
--- /dev/null
+++ b/src/tests/add/__snapshots__/dep.spec.ts.snap
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`dep should fail if dependancy is already in package.json 1`] = `[Error: Config not found. Tried to look for a .nbxrc, .nbxrc.json, .nbxrc.yaml, .nbxrc.yml, .nbxrc.js]`;
+
+exports[`dep should fail if dev dependancy is already in package.json 1`] = `[Error: chalk is already installed in this project.]`;
+
+exports[`dep should fail if no package.json found 1`] = `[Error: There is no package.json not found in the current folder]`;
+
+exports[`dep should print help correctly 1`] = `
+Array [
+  "proxy to yarn add, plus gitmoji commit
+",
+  "USAGE
+  $ nbx add:dep DEP
+
+ARGUMENTS
+  DEP  The dependency to install
+
+OPTIONS
+  -D, --dev       install as a dev dependency
+  -h, --help      show CLI help
+  -v, --verbose   Verbose output
+  --[no-]spinner  Enable spinner in cli output, true by default
+
+EXAMPLES
+  $ nbx add:dep -D eslint
+  $ nbx add:dep --dev eslint
+  $ nbx add:dep chalk",
+  "",
+]
+`;
+
+exports[`dep should work with a dev dependency 1`] = `
+Array [
+  "Adding chalk as a dev dependency",
+  "The step was done without any error.",
+]
+`;
+
+exports[`dep should work with dependency 1`] = `
+Array [
+  "Adding chalk as a dependency",
+  "The step was done without any error.",
+]
+`;
diff --git a/src/tests/add/dep.spec.ts b/src/tests/add/dep.spec.ts
new file mode 100644
index 0000000..d3b2244
--- /dev/null
+++ b/src/tests/add/dep.spec.ts
@@ -0,0 +1,145 @@
+import { filesystem, system } from 'gluegun';
+const stripANSI = require('strip-ansi');
+import * as latestVersion from 'latest-version';
+import Dep from '../../commands/add/dep';
+
+jest.setTimeout(90000);
+
+/* eslint-disable no-console,max-nested-callbacks,@typescript-eslint/ban-ts-ignore */
+let consoleLogOutput: string[];
+let execPath: string;
+const originalCwd = process.cwd();
+const originalLog = console.log;
+
+beforeEach(async () => {
+  consoleLogOutput = [];
+  console.log = (x: any) => consoleLogOutput.push(stripANSI(x));
+
+  const tmpDirName = `${new Date().getTime()}-${Math.random() * 100}-add-nbx-test`;
+  execPath = filesystem.path('/', 'tmp', tmpDirName);
+  filesystem.dir(execPath);
+  process.chdir(execPath);
+});
+afterEach(() => {
+  console.log = originalLog;
+  process.chdir(originalCwd);
+  jest.restoreAllMocks();
+  filesystem.remove(execPath);
+});
+
+const initWithConfigAndCommit = async () => {
+  await system.run('git init');
+  filesystem.write('.nbxrc', { git: { user: 'aaa', email: 'bbb' } });
+  filesystem.write('package.json', {});
+  await system.run('touch yarn.lock');
+  await system.run('echo node_modules > .gitignore');
+  await system.run('git add * .nbxrc .gitignore');
+  try {
+    await system.run('git config user.email "you@example.com"');
+    await system.run('git config user.name "Your Name"');
+  } catch {}
+  await system.run('git commit -m "init state"');
+};
+
+describe('dep', () => {
+  it('should print help correctly', async () => {
+    try {
+      await Dep.run(['-h']);
+    } catch {}
+    expect(consoleLogOutput).toMatchSnapshot();
+  });
+  it('should fail if no package.json found', async () => {
+    expect.assertions(1);
+    try {
+      filesystem.remove('package.json');
+      await Dep.run(['chalk', '--no-spinner']);
+      // eslint-disable-next-line unicorn/catch-error-name
+    } catch (e) {
+      expect(e).toMatchSnapshot();
+    }
+  });
+  it('should fail if dependancy is already in package.json', async () => {
+    expect.assertions(1);
+    try {
+      filesystem.write('package.json', { dependencies: { chalk: '2.3.2' } });
+      await Dep.run(['chalk', '--no-spinner']);
+      // eslint-disable-next-line unicorn/catch-error-name
+    } catch (e) {
+      expect(e).toMatchSnapshot();
+    }
+  });
+  it('should fail if dev dependancy is already in package.json', async () => {
+    expect.assertions(1);
+    try {
+      filesystem.write('package.json', { devDependencies: { chalk: '2.3.2' } });
+      await Dep.run(['chalk', '--dev', '--no-spinner']);
+      // eslint-disable-next-line unicorn/catch-error-name
+    } catch (e) {
+      expect(e).toMatchSnapshot();
+    }
+  });
+
+  it('should work with dependency', async () => {
+    await initWithConfigAndCommit();
+    const latestChalk = await latestVersion('chalk');
+
+    await Dep.run(['chalk', '--no-spinner']);
+
+    const packageJson = filesystem.read('package.json', 'json');
+    expect(consoleLogOutput).toMatchSnapshot();
+    expect(packageJson).toStrictEqual({
+      dependencies: {
+        chalk: latestChalk,
+      },
+    });
+    const after = await system.run('git log --name-status  --format="%s"');
+    const afterSlitted = after
+      .split('\n')
+      .map(val => val.trim())
+      .map(val => stripANSI(val))
+      .filter(val => val !== '');
+
+    expect(afterSlitted).toStrictEqual([
+      `:heavy_plus_sign: add chalk@${latestChalk} as a dependency`,
+      'M\tpackage.json',
+      'M\tyarn.lock',
+      'init state',
+      'A\t.gitignore',
+      'A\t.nbxrc',
+      'A\tpackage.json',
+      'A\tyarn.lock',
+    ]);
+  });
+
+  it('should work with a dev dependency', async () => {
+    await initWithConfigAndCommit();
+    const latestChalk = await latestVersion('chalk');
+
+    await Dep.run(['chalk', '-D', '--no-spinner']);
+
+    const packageJson = filesystem.read('package.json', 'json');
+    expect(consoleLogOutput).toMatchSnapshot();
+    expect(packageJson).toStrictEqual({
+      devDependencies: {
+        chalk: latestChalk,
+      },
+    });
+    const after = await system.run('git log --name-status  --format="%s"');
+    const afterSlitted = after
+      .split('\n')
+      .map(val => val.trim())
+      .map(val => stripANSI(val))
+      .filter(val => val !== '');
+
+    expect(afterSlitted).toStrictEqual([
+      `:heavy_plus_sign: add chalk@${latestChalk} as a dev dependency`,
+      'M\tpackage.json',
+      'M\tyarn.lock',
+      'init state',
+      'A\t.gitignore',
+      'A\t.nbxrc',
+      'A\tpackage.json',
+      'A\tyarn.lock',
+    ]);
+  });
+});