```coffeescript
# Map of environment vars to config properties
EnvVars =
  NODE_ENV:     'appMode'
  PORT:         'port'
  LOG_LEVEL:    'logLevel'
  STORAGE_TYPE: 'storageType'
  POSTGRES_URL: 'postgresUrl'
  GZIP:         'gzip'

module.exports = EnvVars
```

Add environment variable for BASE_URL.
user
```coffeescript
# Map of environment vars to config properties
EnvVars =
  NODE_ENV:     'appMode'
  BASE_URL:     'baseUrl'
  PORT:         'port'
  LOG_LEVEL:    'logLevel'
  STORAGE_TYPE: 'storageType'
  POSTGRES_URL: 'postgresUrl'
  GZIP:         'gzip'

module.exports = EnvVars
```
assistant