how to use rest api with auth

[Amol Phatangade]

Not able to use rest API it gives error:

{
"error": {
"code": 401,
"message": "Invalid OAuth session",
"type": "Unauthorized"
}
}

[Shannon S]

Amol,

Could you let us know what product this is for and which version you're using?

Regards,

Shannon

[Amol Phatangade]

i am trying for hypchat. 

my request is:

POST : http://api.hipchat.com/v2/room?auth_token=jpA76hDdKyXDaomCaMvOC22C&auth_test=true

Authorization : Basic YW1vbEBjeWJlcnNwb25zZS5jb206anBBNzZoRGRLeVhEYW9tQ2FNdk9DMjJD

Host: api.hipchat.com

Authorization: Basic jpA76hDdKyXDaomCaMvOC22C

Content-Type : application/x-www-form-urlencoded

in body:

grant_type : grant_type

scope : send_notification+admin_room

response : 

{
"error": {
"code": 400,
"message": "Invalid BASIC-encoded authentication credentials format",
"type": "Bad Request"
}
}

i am not able to understand what is worng in this.