diff --git a/docs/spec.md b/docs/spec.md
new file mode 100644
index 0000000..870409e
--- /dev/null
+++ b/docs/spec.md
@@ -0,0 +1,141 @@
+## Casadoc: Technical specifications describing cross-platform feasibility
+
+##### Summary
+
+The strategic choice, considering high quality UI/UX and performance over a quick-fix migration (using a framework like Ionic), is **React Native**. While it requires more initial work than Ionic, the result will be a robust mobile app that feels truly native on both iOS and Android. The frontend will have to be written in JavaScript entirely but it offers a significantly faster, smoother *native* feel. The PHP code would only serve as the backend API.
+
+##### React Native
+
+* **Architecture:** Renders true native mobile UI components using JavaScript.
+
+* **Frontend Migration:** We won't be able to use the original HTML/CSS output rendered by the PHP code directly. We'll have to rewrite the UI using JSX (React).
+
+* **Language:** JavaScript/TypeScript.
+
+* **Native Features:** React Native supports a large ecosystem of native modules.
+
+#### Technical strategy for migrating Casadoc from PHP to React Native
+
+1. **Architectural Shift**
+
+ **Decoupling**. Currently, our PHP code likely mixes logic and UI (e.g., fetching data from DB and immediately rendering an HTML table).
+
+ - **Current State:** PHP $\rightarrow$ HTML/CSS (Browser renders UI)
+
+ - **Future State:** PHP $\rightarrow$ JSON Data $\rightarrow$ React Native (Mobile renders UI)
+
+2. **Category-Wise Migration Plan**
+
+ - **The Backend (PHP): Transformation to API**
+
+ We do not need to rewrite the backend logic (code), but we must change *how* it delivers data.
+
+ - Create a new set of endpoints specifically for the mobile app.
+
+ - **Authentication:**
+
+ - *Current:* Likely uses Sessions/Cookies (`$_SESSION`).
+
+ - *New:* Switch to **JWT (JSON Web Tokens)**. The app will send a "Token" with every request to prove who the user is.
+
+ - **Response Format:**
+
+ - Stop returning `view('profile.index', $data)`
+
+ - Start returning `json_encode($data)` or `return response()->json($data)`
+
+ - **The Frontend (React Native): Complete Rewrite**
+
+ Most of the work will go into the frontend development since we can't use the HTML/CSS given by PHP directly for rendering.
+
+ **UI Components:**
+
+ - HTML `
` becomes ``
+
+ - HTML `` or `
` becomes ``
+
+ - HTML `` becomes ``
+
+ - HTML `