Cro – elegant reactive services in Raku

# elegant reactive services in Raku Source: [https://cro.raku.org/](https://cro.raku.org/) ## Welcome to Cro Cro is a set of libraries for building reactive distributed systems, lovingly crafted to take advantage of all Raku has to offer\. The high level APIs make the easy things easy, and the asynchronous pipeline concept at Cro's heart makes the hard things possible\. Ready to get started? Just`zef install \-\-/test cro`and check out the[documentation](https://cro.raku.org/docs)\. - [HTTP](https://cro.raku.org/#http) - [Web Sockets](https://cro.raku.org/#ws) - [Tooling](https://cro.raku.org/#tooling) ## Set up your routes, and serve them ``` use Cro::HTTP::Router; use Cro::HTTP::Server; my $application = route { get -> 'greet', $name { content 'text/plain', "Hello, $name!"; } } my Cro::Service $hello = Cro::HTTP::Server.new: :host<localhost>, :port<10000>, :$application; $hello.start; react whenever signal(SIGINT) { $hello.stop; exit; } ``` ## Built\-in HTTP server  HTTP/1\.1 persistent connections  HTTP/2\.0 \(use negotiated with ALPN\)  HTTPS support  Add middleware at the server level  Configure body parsers and serializers  Requests dispatched to the thread pool, to make use of multi\-core CPUs ## Flexible request router ``` # Capture/constrain root segments with a signature. get -> 'product', UUIDv4 $id { content 'application/json', get-product($id); } # Slurp root segments and serve static content get -> 'css', *@path { static 'assets/css', @path; } # Get stuff from the query string get -> 'search', :$term! { content 'application/json', do-search($term); } ``` ## Pluggable body parsing and serialization Enjoy built\-in support for www\-form\-urlencoded, multi\-part, and JSON bodies \- or plug in your own body parsers and serializers\. ``` put -> 'order', UUIDv4 $id { request-body -> %json-object { # Save it, and then... content 'application/json', %json-object; } } ``` ## HTTP client included  Asynchronous API for getting the response and the body \(body delivered all at once or streaming\)  Supports HTTP/1\.1 persistent connections  HTTPS, with optional custom certificate authority  HTTP/2\.0 support, with request multiplexing  Pluggable body parsers/serializers \- the same used by the server \- and middleware support [Previous](https://cro.raku.org/#carousel-http)[Next](https://cro.raku.org/#carousel-http) ## Neatly integrated with the HTTP router ``` my $chat = Supplier.new; get -> 'chat' { web-socket -> $incoming { supply { whenever $incoming -> $message { $chat.emit(await $message.body-text); } whenever $chat -> $text { emit $text; } } } } ``` ## Web socket client A`Supply`\-based web services client is included in Cro\. It's just what you need for using web sockets between services, writing web socket clients, or writing integration tests for services exposed by a web socket\. [Previous](https://cro.raku.org/#carousel-websockets)[Next](https://cro.raku.org/#carousel-websockets)