diff --git a/kanken_online/__init__.py b/kanken_online/__init__.py
index b95881e..ae6abed 100644
--- a/kanken_online/__init__.py
+++ b/kanken_online/__init__.py
@@ -86,6 +86,7 @@ def create_app(test_config=None):
     app.register_blueprint(indices.blueprint)
 
     from . import lang
+    lang.add_translation_commands(app)
 
     @app.route("/translations", methods=["GET", "POST"])
     def strings_translation():
diff --git a/kanken_online/lang.py b/kanken_online/lang.py
index 370b05f..39f861b 100644
--- a/kanken_online/lang.py
+++ b/kanken_online/lang.py
@@ -1,6 +1,8 @@
 import json
+import os
 from pathlib import Path
-from flask import session
+import click
+from flask import Flask, session, current_app
 
 LanguageMapping = dict[str, str]
 
@@ -32,3 +34,45 @@ def localize(text_id: str, language: dict[str, str] = None) -> str:
         preference = session.get("language", "ja")
         language = LANGUAGES.get(preference)
     return language[text_id]
+
+
+@click.command("add-string")
+@click.argument("string")
+def add_string(string):
+    """Add a new string to the translations."""
+    for path in Path("kanken_online/static/lang").glob("*.json"):
+        with open(path) as f:
+            data = json.load(f)
+            data[string] = ""
+        with open(path, mode="w") as f:
+            json.dump(data, f, ensure_ascii=False, indent=0)
+
+@click.command("set-string")
+@click.argument("lang")
+@click.argument("string")
+def set_string(lang, string, value):
+    """Set the value of a string for a particular language's translation file."""
+    path = Path("kanken_online/static/lang", f"{lang}.json")
+    with open(path) as f:
+        data = json.load(f)
+        data[string] = value
+    with open(path, mode="w") as f:
+        json.dump(data, f, ensure_ascii=False, indent=0)
+
+@click.command("rename-string")
+@click.argument("string")
+@click.argument("new_name")
+def rename_string(string, new_name):
+    """Rename a string in the translations files."""
+    for path in Path("kanken_online/static/lang").glob("*.json"):
+        with open(path) as f:
+            data = json.load(f)
+            data[new_name] = data[string]
+            del data[string]
+        with open(path, mode="w") as f:
+            json.dump(data, f, ensure_ascii=False, indent=0)
+
+def add_translation_commands(app: Flask):
+    app.cli.add_command(add_string)
+    app.cli.add_command(set_string)
+    app.cli.add_command(rename_string)