v4FeaturesLogging and Debugging
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This is the documentation for the old GraphQL Yoga version 4. We recommend upgrading to the latest GraphQL Yoga version 5.

Migrate to GraphQL Yoga v5

Logging and Debugging

Logging

Yoga uses 4 log levels debug, info, warn and error. By default, Yoga will only log info, warn and error messages.

Log Level Overview

error

  • Only log unexpected errors

warn

  • All prior log levels
  • deprecation notices

info

  • All prior log levels
  • Information about the current state of the system

debug

  • All prior log levels
  • Processing of GraphQL parameters
  • Parsing of GraphQL parameters
  • Execution or subscription start
  • Received GraphQL operation variables
  • Execution or subscription end
  • GraphiQL rendering
  • Health checks

Enabling Debug Logging

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Instead, on JavaScript environments that support environment variables via process.env (e.g. Node.js), you can also conditionally enable debug logging by setting the DEBUG environment variable to 1.

Custom log level
import { createServer } from 'node:http'
import { createYoga } from 'graphql-yoga'
import { schema } from './my-schema.js'
 
const yoga = createYoga({
  schema,
  logging: 'debug'
})

Change log level

You can customize the log lovel by passing on of the 4 levels to the logging option:

💡

We recommend not changing the default log level and only recommend changing it if you know what you are doing.

Custom log level
import { createServer } from 'node:http'
import { createYoga } from 'graphql-yoga'
import { schema } from './my-schema.js'
 
const yoga = createYoga({
  schema,
  logging: 'warn'
})

Specifying the log level of warn will only log warn and error messages being logged.

Custom logger

You can of course provide your own logger for piping to your favorite logging service/utility:

import { createServer } from 'node:http'
import { createYoga } from 'graphql-yoga'
import { logger } from './my-logger.js'
import { schema } from './my-schema.js'
 
const yoga = createYoga({
  schema,
  logging: {
    debug(...args) {
      logger.debug(...args)
    },
    info(...args) {
      logger.info(...args)
    },
    warn(...args) {
      logger.warn(...args)
    },
    error(...args) {
      logger.error(...args)
    }
  }
})
 
const server = createServer(yoga)
 
server.listen(4000, () => {
  console.info('Server is running on http://localhost:4000/graphql')
})

Further hook into the logging system by leveraging envelop’s useLogger plugin:

import { createServer } from 'node:http'
import { createYoga, useLogger } from 'graphql-yoga'
import { logger } from './my-logger'
import { schema } from './my-schema'
 
const yoga = createYoga({
  schema,
  plugins: [
    useLogger({
      logFn: (eventName, args) => {
        // Event could be execute-start / execute-end / subscribe-start / subscribe-end / etc.
        // args will include the arguments passed to execute/subscribe (in case of "start" event) and additional result in case of "end" event.
        logger.debug(eventName, ...args)
      }
    })
  ]
})
 
const server = createServer(yoga)
 
server.listen(4000, () => {
  console.info('Server is running on http://localhost:4000/graphql')
})