Hacky way to combine PostGraphile with another GraphQL schema

graphql.js

import express from 'express';
import bodyParser from 'body-parser';
import { graphqlExpress, graphiqlExpress } from 'apollo-server-express';

import { postgraphile } from 'postgraphile';
import { createApolloFetch } from 'apollo-fetch';
import {
  makeRemoteExecutableSchema,
  introspectSchema,
  mergeSchemas,
} from 'graphql-tools';

import stripe from './stripe';

export default async (app, knex) => {
  const internalApp = express();
  internalApp.use(bodyParser.json());
  internalApp.use(postgraphile(process.env.DATABASE_URL, 'public', {
    pgSettings: (req) => {
      const userId = req.headers['user-id'];
      return {
        role: 'app_user',
        ...(userId
          ? { 'jwt.claims.user_id': String(userId) }
          : {}),
      };
    },
  }));
  internalApp.listen(process.env.INTERNAL_PORT, () => {
    console.log(`postgraphile server listening on port ${process.env.INTERNAL_PORT}`);
  });

  const pgFetcher = createApolloFetch({
    uri: `http://localhost:${process.env.INTERNAL_PORT}/graphql`,
  });
  pgFetcher.use(({ request, options }, next) => {
    if (!options.headers) {
      options.headers = {}; // eslint-disable-line
    }
    const { context } = request;
    // eslint-disable-next-line
    options.headers['user-id'] = context &&
      context.graphqlContext &&
      context.graphqlContext.userId;
    next();
  });
  const pgSchema = makeRemoteExecutableSchema({
    schema: await introspectSchema(pgFetcher),
    fetcher: pgFetcher,
  });

  const schema = mergeSchemas({
    schemas: [pgSchema, stripe.schema, stripe.linkTypeDefs],
    resolvers: stripe.linkResolvers,
  });

  // The GraphQL endpoint
  app.use('/graphql', graphqlExpress(req => ({
    schema,
    context: {
      userId: req.user && req.user.id, // to use in our resolvers + send to postgraphile
      knex, // so we can make direct DB calls in our stripe resolvers
    },
  })));

  // GraphiQL, a visual editor for queries
  if (process.env.NODE_ENV === 'development') {
    app.get('/graphiql', graphiqlExpress({
      endpointURL: '/graphql',
    }));
  }

  return true;
};