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README.md

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+# Underpass
+
+Self-hosted [ngrok](https://ngrok.com) alternative.
+
+## Installation (CLI)
+
+```bash
+brew install cjdenio/tap/underpass
+```
+
+Or, download a release from the [releases page](https://github.com/cjdenio/underpass/releases/latest).
+
+## Usage with hosted server
+
+There's a hosted instance running at https://underpass.clb.li.
+
+```bash
+underpass -p <port> -s <optional subdomain>
+```
+
+## Self-hosting
+
+(more docs coming soon, possibly)
+
+```bash
+go run ./cmd/server --host <host here>
+```
+
+```bash
+underpass -p <port> --host <host here> -s <optional subdomain>
+```
+
+## Known caveats
+
+- No WebSocket support