Use graphiql-explorer in your Koa app.

Installation

npm install koa-graphql-explorer

Usage

const graphiqlExplorer = require('koa-graphiql-explorer')
const Koa = require('koa')

const app = new Koa()

app.use(graphiqlExplorer({
  mountPoint: '/graphiql',
  graphqlEndpoint: '/graphql', 
  defaultQuery: `query MyQuery {}`
}))