First Steps

Using Envelop is straight-forward and intuitive, in this section you will learn how to install and set up a GraphQL server using Envelop from scratch.

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In case you are being referred to the Envelop documentation from a framework or library that implements envelop, you can straight dive into the Plugin Hub or head over to the Plugin Tutorial for learning how to write your plugins.

Installation

Start by adding the core of envelop and graphql to your codebase.

npm i @envelop/core graphql

Create Your First Envelop

After installing the @envelop/core package, you can use the envelop function for creating your getEnveloped function. We use a simple GraphQL schema that we build with the buildSchema function from graphql.

import * as GraphQLJS from 'graphql'
import { envelop, useEngine, useSchema } from '@envelop/core'
 
const schema = buildSchema(/* GraphQL */ `
  type Query {
    hello: String
  }
`)
 
export const getEnveloped = envelop({
  plugins: [useSchema(schema)]
})

Use Your Envelop

The result of envelop is a factory function that allows you to get everything you need for the GraphQL execution: parse, validate, contextBuilder, execute and subscribe. It is usually named getEnveloped.

By calling the getEnveloped function you will get all the primitive functions required for the GraphQL execution layer.

// prettier-ignore
const {
  contextFactory,
  parse,
  validate,
  execute,
  subscribe,
  schema,
} = getEnveloped()

Add Plugins to Your Envelop

After you set up your base Envelop, you can start customizing your GraphQL server. Adding new functionality is as easy as adding a new envelop plugin to your base envelop setup.

Let’s add a parser and validation cache, so sending the same operation string sent to our server is cached using an LRU cache, allowing to improve the overall performance of the GraphQL execution layer.

npm i @envelop/parser-cache @envelop/validation-cache

import { buildSchema } from 'graphql'
import { envelop, useEngine, useSchema } from '@envelop/core'
import { useParserCache } from '@envelop/parser-cache'
import { useValidationCache } from '@envelop/validation-cache'
 
const schema = buildSchema(/* GraphQL */ `
  type Query {
    hello: String
  }
`)
 
const getEnveloped = envelop({
  plugins: [
    // all enabled plugins
    useSchema(schema),
    useParserCache(),
    useValidationCache()
  ]
})

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A list of all available plugins can be found in the Plugins page.

Use Your Envelop with an HTTP Server

You can build a very simple GraphQL HTTP server from scratch, by using the Node.js http module and only these functions.

import { createServer } from 'node:http'
import { GraphQLError } from 'graphql'
import { getEnveloped } from './envelop'
 
const httpServer = createServer(async (req, res) => {
  try {
    // body parsing
    req.body = await new Promise((resolve, reject) => {
      let data = ''
      req.on('data', chunk => {
        data += String(chunk)
      })
      req.on('end', () => {
        resolve(data)
      })
      req.on('error', err => reject(err))
    })
 
    const {
      // Get the GraphQL execution functions with attached plugin handlers
      parse,
      validate,
      contextFactory,
      execute,
      schema
      // pass in an initial context that all plugins can consume and extend
    } = getEnveloped({ req })
 
    // Parse request body JSON
    const { query, variables } = JSON.parse(req.body)
    const document = parse(query)
    const validationErrors = validate(schema, document)
 
    if (validationErrors.length > 0) {
      return res.end(JSON.stringify({ errors: validationErrors }))
    }
 
    // Build the context and execute
    const contextValue = await contextFactory()
    const result = await execute({
      document,
      schema,
      variableValues: variables,
      contextValue
    })
 
    // Send the response
    res.end(JSON.stringify(result))
  } catch (err) {
    if (err instanceof GraphQLError === false) {
      err = new GraphQLError(err.message)
    }
    res.end(JSON.stringify({ errors: [err] }))
  }
})
 
httpServer.listen(3000)

After starting this server we can send a GraphQL operation using curl, yielding a response of {"data":{"__typename":"Query"}}.

curl \
  -X POST \
  -d '{"query":"{__typename}"}' \
  http://localhost:3000

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This example uses the Node.js http module and is a very simplified handler that does not strictly follow the GraphQL over HTTP specification as it does not handle headers or respect HTTP methods. For actual production usage, we recommend using Envelop with one of the popular and battle-tested HTTP frameworks and servers. Check the examples on our Integrations page.

Introduction Integrations and Examples