diff --git a/cd/__init__.py b/cd/__init__.py
index befcf35..6b90987 100644
--- a/cd/__init__.py
+++ b/cd/__init__.py
@@ -6,7 +6,7 @@ import env
 from rwx import fs
 from rwx import ps
 
-COMMANDS_PREFIX = 'cd-'
+COMMANDS_PREFIX = "cd-"
 
 projects = Projects(os.environ)
 project = Project(projects)
@@ -17,8 +17,8 @@ def cd_browse_workspace():
 
 
 def cd_build_project():
-    for extension in ['py', 'sh']:
-        path = os.path.join(project.root, f'build.{extension}')
+    for extension in ["py", "sh"]:
+        path = os.path.join(project.root, f"build.{extension}")
         if os.path.exists(path):
             ps.run(path)
             break
@@ -27,14 +27,14 @@ def cd_build_project():
 
 
 def cd_clone_branch():
-    print(f'''\
+    print(f"""\
 {project.url}
 ↓
-''', end=str(), flush=True)
-    ps.run('git',
-        'clone',
-        '--branch', project.branch,
-        '--',
+""", end=str(), flush=True)
+    ps.run("git",
+        "clone",
+        "--branch", project.branch,
+        "--",
         project.url,
         project.root,
     )
@@ -42,25 +42,25 @@ def cd_clone_branch():
 
 def cd_list_environment():
     for variable, value in sorted(projects.environment.items()):
-        print(variable, '=', value)
+        print(variable, "=", value)
 
 
 def cd_synchronize():
-    host = 'rwx.work'
-    source = 'out'
-    user = 'cd'
+    host = "rwx.work"
+    source = "out"
+    user = "cd"
     #
     root = os.sep.join([str(),
                         user, project.branch, projects.group, project.name])
     #
-    target = f'{user}@{host}:{root}'
-    ps.run('rsync',
-        '--archive',
-        '--delete-before',
-        '--verbose',
-        f'{source}/',
-        f'{target}/',
-        '--dry-run',
+    target = f"{user}@{host}:{root}"
+    ps.run("rsync",
+        "--archive",
+        "--delete-before",
+        "--verbose",
+        f"{source}/",
+        f"{target}/",
+        "--dry-run",
     )
 
 
@@ -84,38 +84,38 @@ def cat(file: str):
 
 
 def install_commands(path):
-    step('Install commands')
-    user = '/usr/local/bin'
+    step("Install commands")
+    user = "/usr/local/bin"
     for command in [
-        'browse-workspace',
-        'build-project',
-        'clone-branch',
-        'list-environment',
-        'synchronize',
+        "browse-workspace",
+        "build-project",
+        "clone-branch",
+        "list-environment",
+        "synchronize",
     ]:
         print(command)
-        os.symlink(path, os.path.join(user, f'{COMMANDS_PREFIX}{command}'))
+        os.symlink(path, os.path.join(user, f"{COMMANDS_PREFIX}{command}"))
 
 
 def set_ssh(*arguments):
-    step('Set SSH')
+    step("Set SSH")
     #
     ssh_key, ssh_hosts = arguments
     #
-    ssh_type = 'ed25519'
+    ssh_type = "ed25519"
     #
-    home = os.path.expanduser('~')
+    home = os.path.expanduser("~")
     #
-    ssh = os.path.join(home, '.ssh')
+    ssh = os.path.join(home, ".ssh")
     os.makedirs(ssh, exist_ok=True)
     os.chmod(ssh, 0o700)
     #
-    key = os.path.join(ssh, f'id_{ssh_type}')
+    key = os.path.join(ssh, f"id_{ssh_type}")
     if ssh_key:
         fs.write(key, ssh_key)
         os.chmod(key, 0o400)
     #
-    known = os.path.join(ssh, 'known_hosts')
+    known = os.path.join(ssh, "known_hosts")
     if ssh_hosts:
         fs.write(known, ssh_hosts)
         os.chmod(known, 0o400)