Integration with Koa

Koa is a new web framework designed by the team behind Express, which aims to be a smaller, more expressive, and more robust foundation for web applications and APIs. GraphQL Yoga can be integrated easily as a route to the existing Koa application with a few lines of code. So you can benefit middlewares written for Koa with GraphQL Yoga.

Installation

npm i koa graphql-yoga graphql

Example

import { createYoga } from 'graphql-yoga'
import Koa from 'koa'
 
const app = new Koa()
 
const yoga = createYoga<Koa.ParameterizedContext>()
 
// Bind GraphQL Yoga to `/graphql` endpoint
app.use(async ctx => {
  // Second parameter adds Koa's context into GraphQL Context
  const response = await yoga.handleNodeRequestAndResponse(ctx.req, ctx.res, ctx)
 
  // Set status code
  ctx.status = response.status
 
  // Set headers
  response.headers.forEach((value, key) => {
    ctx.append(key, value)
  })
 
  // Converts ReadableStream to a NodeJS Stream
  ctx.body = response.body
})
 
app.listen(4000, () => {
  console.log(`Running a GraphQL API server at http://localhost:4000/${yoga.graphqlEndpoint}`)
})

You can also check a full example on our GitHub repository here