# Bertrand
Building prototypes for backend systems isn't always easy, so Bertrand lets you define a simple HTML file like this one:
```html
Bertrand Test
```
We've got a few `div`s with the classes `bertrand` and `bstate:`. When we run `bertrand example.html`, we'll have a local file server started (you can customise where with `--host` and `-p`/`--port`) which will, when the index is loaded in a browser, initially display *This is state A!*, because that was `bertrand-init`. However, we can send messages to it with a command like the following:
```
curl -X POST -d "stateB" http://localhost:8080/api/send
```
And that will be relayed by the server to all connected clients, who will switch to displaying the `bstate:stateB` `div`. That's pretty much all there is to it!
This lets you easily create state-based demos of backend systems by linking up your backend to Bertrand, and then displaying a browser-based representation of what's going on. In my personal experience, this resonates much more than a CLI demo!
*Note: you can provide either a single HTML file or a directory containing an `index.html` to Bertrand, and it will serve everything in there.*
## Installation
You'll need a [Rust toolchain](https://rustup.rs) to install Bertrand, and then you can run:
```
cargo install bertrand
```
## License
See [`LICENSE`](LICENSE).