get your graphql schema

get_schema.js

var fetch = require('node-fetch');
var fs = require('fs');

const {
    buildClientSchema,
    introspectionQuery,
    printSchema,
} = require('graphql/utilities');

console.log(introspectionQuery);

fetch('http://localhost:4000/api', {
    method: 'POST',
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
    },
    body: JSON.stringify({ 'query': introspectionQuery }),
})
    .then(res => res.json())
    .then(res => {
        const schemaString = printSchema(buildClientSchema(res.data));
        console.log("sgdfdg", schemaString);
        fs.writeFileSync('data/schema.json', JSON.stringify(res, null, 2));
        fs.writeFileSync('data/schema.graphql', schemaString);
    });