diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..3f2e280
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 falltwo
+
+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.md b/README.md
index 1441651..ffd0a68 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,7 @@
 [![Release](https://img.shields.io/github/v/release/falltwo/AI-Risk-Based-Inventory-ERP?display_name=tag)](https://github.com/falltwo/AI-Risk-Based-Inventory-ERP/releases)
 ![Python](https://img.shields.io/badge/Python-3.11%2B-3776AB?logo=python&logoColor=white)
 ![Streamlit](https://img.shields.io/badge/UI-Streamlit-FF4B4B?logo=streamlit&logoColor=white)
+[![License](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
 
 > **v1.0 — A governed supply-chain AI decision loop**
 > AI makes judgments and proposals; humans retain execution authority. Protected AI/Gateway procurement writes can be approved, replayed, and traced.
@@ -163,3 +164,7 @@ docs/                        architecture diagrams, runbooks, and release notes
 - [v0.1 English release notes](docs/releases/v0.1.md)
 
 Stack: Python 3.11 · Streamlit · SQLite · LiteLLM · FastAPI · LINE Messaging API · Plotly
+
+## License
+
+Released under the [MIT License](LICENSE).
diff --git a/README.zh.md b/README.zh.md
index ed54951..7d0158f 100644
--- a/README.zh.md
+++ b/README.zh.md
@@ -6,6 +6,7 @@
 [![Release](https://img.shields.io/github/v/release/falltwo/AI-Risk-Based-Inventory-ERP?display_name=tag)](https://github.com/falltwo/AI-Risk-Based-Inventory-ERP/releases)
 ![Python](https://img.shields.io/badge/Python-3.11%2B-3776AB?logo=python&logoColor=white)
 ![Streamlit](https://img.shields.io/badge/UI-Streamlit-FF4B4B?logo=streamlit&logoColor=white)
+[![License](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
 
 > **v1.0 — 可治理的供應鏈 AI 決策閉環**
 > AI 負責判斷與提案，人類保留執行權；受保護的 AI／Gateway 採購寫入可被審批、重放與追溯。
@@ -163,3 +164,7 @@ docs/                        架構圖、runbook 與 Release notes
 - [v0.1 English release notes](docs/releases/v0.1.md)
 
 技術組成：Python 3.11 · Streamlit · SQLite · LiteLLM · FastAPI · LINE Messaging API · Plotly
+
+## 授權
+
+本專案採用 [MIT License](LICENSE)。