Improve relay testability and CLI onboarding

README.md

@@ -72,15 +72,26 @@ peek prints a public URL.
 
 | Option | Use |
 | --- | --- |
-| `--token` | same value as `PEEK_AUTH_TOKEN` |
 | `--domain` | hosted peek domain, like `example.com` |
+| `--token` | same value as `PEEK_AUTH_TOKEN` |
 | `--subdomain` | public URL name, like `myapp` |
 | `--password` | require a password for visitors |
+| `--server` | full relay WebSocket URL, like `wss://example.com/tunnel` |
 
 `--token` creates the tunnel. `--password` protects the public URL and is optional.
 
 Without `--subdomain`, peek creates a random name. Without `--password`, the URL is public.
 
+Environment variables:
+
+```bash
+PEEK_DOMAIN=example.com
+PEEK_AUTH_TOKEN=change-me
+PEEK_PASSWORD=optional-visitor-password
+```
+
+`PEEK_SERVER` can replace `PEEK_DOMAIN` when you need a full WebSocket URL. `PEEK_TOKEN` is still accepted as an old alias for `PEEK_AUTH_TOKEN`.
+
 ---
 
 ### Uninstall the CLI

crates/peek-client/Cargo.toml

@@ -9,6 +9,7 @@ path = "src/main.rs"
 
 [dependencies]
 peek-proto = { path = "../peek-proto" }
+clap = { version = "4", features = ["derive"] }
 tokio = { version = "1", features = ["full"] }
 tokio-tungstenite = { version = "0.29", features = ["native-tls"] }
 futures-util = "0.3"