Blest-js NPM | npm.io

BLEST.js

The NodeJS reference implementation of BLEST (Batch-able, Lightweight, Encrypted State Transfer), an improved communication protocol for web APIs which leverages JSON, supports request batching and selective returns, and provides a modern alternative to REST. It includes examples for Connect, Express, Fastify, Hapi, and Koa.

To learn more about BLEST, please visit the website: https://blest.jhunt.dev

For a front-end implementation in React, please visit https://github.com/jhuntdev/blest-react

Features

Built on JSON - Reduce parsing time and overhead
Request Batching - Save bandwidth and reduce load times
Compact Payloads - Save more bandwidth
Selective Returns - Save even more bandwidth
Single Endpoint - Reduce complexity and improve data privacy
Fully Encrypted - Improve data privacy

Installation

Install BLEST.js from npm

With npm:

npm install --save blest-js

or using yarn:

yarn add blest-js

Usage

The default export of this library has an interface similar to Express or Connect. It also provides a Router class with a handle method for use in an existing NodeJS application and an HttpClient class with a request method for making BLEST HTTP requests.

const express = require('express');
const blest = require('blest-js');

const app = blest({
  timeout: 1000,
  url: '/',
  cors: 'http://localhost:3000'
});
const port = 8080;

const authMiddleware = (params, context) => {
  if (params?.name) {
    context.user = {
      name: params.name
    };
  } else {
    throw new Error('Unauthorized');
  }
};

const greetController = (params, context) => {
  return {
    greeting: `Hi, ${context.user?.name}!`
  };
};

const errorHandler = (params, context, error) => {
  console.log(error);
};

app.use(errorHandler);

app.use(authMiddleware);

app.route('greet', greetController);

app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

Router

This example uses Express, but you can find examples with other frameworks here.

const express = require('express');
const { Router } = require('blest-js');

const app = express();
const port = 8080;

// Create some middleware (optional)
const authMiddleware = (params, context) => {
  if (params?.name) {
    context.user = {
      name: params.name
    };
  } else {
    throw new Error('Unauthorized');
  }
};

// Create a route controller
const greetController = (params, context) => {
  return {
    greeting: `Hi, ${context.user?.name}!`
  };
};

// Create a BLEST router
const router = new Router({ timeout: 1000 });
router.route('greet', authMiddleware, greetController);

// Parse the JSON body
app.use(express.json());

// Use the request handler
app.post('/', async (req, res, next) => {
  const [result, error] = await router.handle(req.body, {
    headers: req.headers
  });
  if (error) {
    return next(error);
  } else {
    res.json(result);
  }
});

// Listen for requests
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

HttpClient

const { HttpClient } = require('blest-js');

// Create a client
const client = new HttpClient('http://localhost:8080', {
  maxBatchSize: 25,
  bufferDelay: 10,
  headers: {
    'Authorization': 'Bearer token'
  }
});

// Send a request
client.request('greet', { name: 'Steve' }, ['greeting'])
.then((result) => {
  // Do something with the result
})
.catch((error) => {
  // Do something in case of error
});