Google OAUTH2 no refresh_token received

I am using emberjs and i could get this response from http://ift.tt/1GDfmSD

{
 "access_token": "snip",
 "token_type": "Bearer",
 "expires_in": 3600,
 "id_token": "snip"
}

but i am never getting refresh token not even on first authentication. I am stuck with it for hours can anyone help me

My request params

code:4/6_Rm706y9Y4vAFSiR6BAF6GXEIQgG8IKkk_8JHSC7sU
redirect_uri:http://localhost:8080/app
client_id:****************
client_secret:****************
scope: null
grant_type:authorization_code
access_type:offline
approval_prompt:force