Basics

Select

$ echo '{"name":"Tom"}' | dasel -r json 'name'
"Tom"

Put

$ echo '{"name":"Tom"}' | 
  dasel put -r json -t string -v '[e-mail]' 'email'
{
  "email": "[e-mail]",
  "name": "Tom"
}

Delete

$ echo '{
  "email": "[e-mail]",
  "name": "Tom"
}' | dasel delete -r json 'email'
{
  "name": "Tom"
}