---
title: JSGI? SVR.JS has implemented it!
date: 2023-08-11 19:56:08
tags:
- jsgi
- javascript
categories:
- [News]
- [Tips]
---
**We have recently added support for PHP-CGI and SCGI. We have implemented JSGI in SVR.JS through new [YellowSquare](https://svrjs.org/dl/mods) mod.** We have more specifically implemented JSGI Level 0/A Draft 2 Proposal (aka JSGI 0.3).
JSGI (JavaScript Gateway Interface) is an interface between JavaScript web applications and web servers. It is inspired by Rack by Ruby and WSGI by Python. JSGI is included in and further developed by the CommonJS project.
Since SVR.JS is written in JavaScript, we could easily implement JSGI.
This blog post will instruct you, how to set up JSGI web applications on SVR.JS.
## Setting up JSGI
First of all, [download](https://svrjs.org/) and install SVR.JS web server. You can also use `create-svrjs-server` tool or [SVR.JS installer](https://svrjs.org/dl/installer) to install SVR.JS.
After setting up SVR.JS, download and install [YellowSquare](https://svrjs.org/dl/mods) to _mods_ directory.
JSGI web applications in YellowSquare have *.jsgi* or *.jsgi.js* extensions and reside in *jsgi-bin* directory in the web root.
Create an example JSGI web application in *<webroot>/jsgi-bin/hello.jsgi* with those contents:
```js
var util = require("util");
exports.app = function(request) {
var requestObjectJson = util.inspect(request);
return {
status: 200,
headers: {
"Content-Type": "text/html"
},
body: [
"Hello World!Hello World!
JSGI request object:
",
requestObjectJson.replace(/&/g,"&").replace(/ /g," ").replace(/>/g,">").replace(/"),
""
]
}
};
```
After creating JSGI application, run SVR.JS using `node svr.js` or `bun run svr.js` and visit JSGI page (for example http://localhost/jsgi-bin/hello.jsgi). You will then see this page:
**We have set up JSGI!** You need to note that every change in JSGI application will require restart of SVR.JS in order to be applied. Also, when JSGI error occurs, it may be printed into server log, crash the server, or invoke 500 error like one below:
