db.createUser({ user: '<some username>', pwd: passwordPrompt(), roles: [{ role: 'readWrite', db: '<your database>' }] }) code example

Example: mongodb create user

use admin
db.createUser(
   {
     user: "restricted",
     pwd: passwordPrompt(),      // Or  "<cleartext password>"
     roles: [ { role: "readWrite", db: "reporting" } ],
     authenticationRestrictions: [ {
        clientSource: ["192.0.2.0"],
        serverAddress: ["198.51.100.0"]
     } ]
   }
)