Add README with usage docs

README.md

@@ -1,4 +1,73 @@
-# 👟 sneaker
+# sneaker
 
-don't ask
+An HTTP tunnel server and client. Expose a local server to the internet through a WebSocket-based tunnel with auto-assigned subdomains.
 
+## Install
+
+```sh
+bun add @because/sneaker
+```
+
+## Server
+
+Run the tunnel server:
+
+```sh
+bun run src/server.tsx
+```
+
+The server exposes:
+
+- `GET /health` — returns the current git SHA
+- `GET /tunnels` — lists active tunnel connections
+- `GET /tunnel/:app` — redirects to the app's subdomain
+- `GET /tunnel?app=NAME` — WebSocket endpoint for clients to establish a tunnel (optional `subdomain` query param to request a specific subdomain)
+
+Incoming HTTP requests to `SUBDOMAIN.your-server.com` are forwarded through the WebSocket to the connected client and proxied to the local target.
+
+The server adds an `x-sneaker` header with the server's hostname to all proxied requests.
+
+## Client
+
+```ts
+import { connect } from "@because/sneaker"
+
+const tunnel = connect({
+  server: "ws://your-server.com",
+  app: "my-app",
+  target: "http://localhost:3000",
+  subdomain: "my-app",       // optional: request a specific subdomain
+  reconnect: true,            // optional: auto-reconnect (default: true)
+  onOpen(subdomain) {
+    console.log(`Tunnel open: ${subdomain}.your-server.com`)
+  },
+  onClose() {
+    console.log("Tunnel closed")
+  },
+  onRequest(req) {
+    console.log(`${req.method} ${req.path}`)
+  },
+  onError(err) {
+    console.error(err)
+  },
+})
+
+// Later:
+tunnel.close()
+```
+
+### Client options
+
+| Option | Type | Description |
+|---|---|---|
+| `server` | `string` | WebSocket URL of the tunnel server |
+| `app` | `string` | App name identifier |
+| `target` | `string` | Local URL to proxy requests to |
+| `subdomain` | `string?` | Request a specific subdomain |
+| `reconnect` | `boolean?` | Auto-reconnect on disconnect (default: `true`) |
+| `onOpen` | `(subdomain: string) => void` | Called when tunnel is established |
+| `onClose` | `() => void` | Called when tunnel disconnects |
+| `onRequest` | `(req) => void` | Called for each proxied request |
+| `onError` | `(error: Error) => void` | Called on errors |
+
+Binary responses (images, fonts, etc.) are automatically base64-encoded over the tunnel and decoded by the server.