docs: replace placeholder README with project overview

README.md

@@ -1,3 +1,57 @@
+# static-frontend
 
-env file
+Web frontend for Static — a cross-chain swap UI that connects Solana, Polygon (EVM), Tron, and Lightning. Built with Create React App, TypeScript, Tailwind CSS, and an Apollo GraphQL client talking to the Static backend.
+
+## Stack
+
+- React 18 + TypeScript (Create React App / `react-scripts` 5)
+- Tailwind CSS
+- Apollo Client (`@apollo/client`) for GraphQL
+- Solana wallet adapter (`@solana/wallet-adapter-*`, Backpack)
+- Ethers v6 + `@web3modal/ethers` (WalletConnect) for Polygon
+- `webln` for Lightning, `qrcode.react` for invoice display
+
+See `package.json` for the full dependency list.
+
+## Setup
+
+```bash
+bun install   # or: yarn install / npm install
+```
+
+### Environment
+
+A `.env` file in the repo root is required. The keys come from the team Notion page:
 https://www.notion.so/Static-frontend-env-9e7224d8da0d4979857e04b8bf7f1f31?pvs=4
+
+Variables consumed by the app must be prefixed with `REACT_APP_` (CRA convention). Currently used:
+
+- `REACT_APP_WALLET_CONNECT_PROJECT_ID` — WalletConnect Cloud project ID for Web3Modal (`src/App.tsx`).
+
+## Development
+
+```bash
+bun start         # runs `react-scripts start` on http://localhost:3000
+bun test          # runs `react-scripts test` (Jest, watch mode)
+bun run build     # production build into ./build
+```
+
+The GraphQL endpoint is configured in `src/App.tsx` (`HOST` constant). Point it at a local backend by switching the commented `HOST` value.
+
+## Layout
+
+```
+src/
+  App.tsx          # Apollo + Web3Modal bootstrap
+  Chain.tsx        # chain picker
+  Connect.tsx      # wallet connect flow
+  Swap.tsx         # swap UI
+  Order.tsx        # order lifecycle
+  PolygonAddress.tsx, SolAddress.tsx
+  constants.ts
+public/            # CRA static assets (chain/token logos)
+```
+
+## Related
+
+- `static-escrow` — Anchor (Solana) escrow program used by the swap flow.