103 Early Hints

Lets the server send some headers (like links to CSS or JS) before the main response is ready, so the browser can start preloading resources in advance.

When and Why to Use It

Use this to optimize load times. While your server is busy gathering data for the main response, you can fire off a 103 Early Hints to tell the browser ‘Start downloading these CSS & JS files while you wait for my actual response’.

Usage Examples

Shokupan (Functional)

import { HttpCode, get } from 'shokupan';

export const getResource = get('/resource', () => {
    return { message: 'Early Hints' };
}).pipe(HttpCode(103));

Shokupan (Controller)

import { Controller, Get, HttpCode } from 'shokupan';

@Controller('/api')
export class ExampleController {
    @Get('/resource')
    @HttpCode(103)
    getResource() {
        return { message: 'Early Hints' };
    }
}

Express

import express from 'express';
const app = express();

app.get('/resource', (req, res) => {
    res.status(103).json({ message: 'Early Hints' });
});

Nest

import { Controller, Get, HttpCode } from '@nestjs/common';

@Controller('api')
export class ExampleController {
  @Get('resource')
  @HttpCode(103)
  getResource() {
    return { message: 'Early Hints' };
  }
}

Koa

import Koa from 'koa';
const app = new Koa();

app.use(async ctx => {
  if (ctx.path === '/resource' && ctx.method === 'GET') {
    ctx.status = 103;
    ctx.body = { message: 'Early Hints' };
  }
});