diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index 4e94e64..6c98216 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -5,5 +5,6 @@
   "author": {
     "name": "umiyosh"
   },
-  "repository": "https://github.com/umiyosh/motion-render"
+  "repository": "https://github.com/umiyosh/motion-render",
+  "license": "MIT"
 }
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..8bbac0c
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 umiyosh
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.ja.md b/README.ja.md
index 01ec3fb..f5f6683 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -253,3 +253,7 @@ scripts/quality-gate*.mjs # 今の指摘をベースラインと比べる
 tests/                    # Vitest のユニットテストと描画のスモークテスト（フィクスチャの store、代役のプレーヤー、HTML の映像）
 vitest.config.ts          # テストの設定とカバレッジ 80% の基準
 ```
+
+## ライセンス
+
+[MIT](LICENSE)
diff --git a/README.md b/README.md
index 7477299..a7aabbd 100644
--- a/README.md
+++ b/README.md
@@ -254,3 +254,7 @@ scripts/quality-gate*.mjs # Compares the current findings with the baseline
 tests/                    # Vitest unit tests and render smoke tests (fixture store, a stub player, HTML films)
 vitest.config.ts          # Test settings and the 80% coverage gate
 ```
+
+## License
+
+[MIT](LICENSE)
diff --git a/package.json b/package.json
index 5d3b357..4ecb8bd 100644
--- a/package.json
+++ b/package.json
@@ -2,6 +2,7 @@
   "name": "motion-render-plugin",
   "version": "1.0.0",
   "private": true,
+  "license": "MIT",
   "description": "Claude Code plugin root for motion-render. Claude Code installs these dependencies when it installs the plugin; bin/motion-render runs the CLI in skills/motion-render.",
   "type": "module",
   "engines": {