palette/jsx/bundles/graphiql.js

import React from 'react'
import ReactDOM from 'react-dom'
import GraphiQL from 'graphiql'
import axios from 'axios'
import 'graphiql/graphiql.css'

function fetcher (params) {
  return axios.post(
    '/api/graphql',
    JSON.stringify(params),
    {
      headers: {'Content-Type': 'application/json'},
    }
  ).then(({data}) => data)
}

ReactDOM.render(<GraphiQL fetcher={fetcher} />, document.getElementById('graphiql'))