Calling Uber API from Rails: {"error": "invalid_client"} -

been @ day.

using rails call uber api , failing access token. grabbing authorization code works, exchanging access token not.

i've tried , without oauth 2.0 gem , made sure keys accurate. tried on 2 separate uber accounts, too. combinations give same error: {"error": "invalid_client"}.

i'll post non-oauth code below. params[:code] auth code returned uber.

uri = uri.parse('https://login.uber.com/oauth/v2/token') https = net::http.new(uri.host, uri.port) https.use_ssl = true  headers = {   # authentication content-type not json   # 'content-type'  => 'application/x-www-form-urlencoded',   'authorization' => 'token ' + @server_token }  request = net::http::post.new(uri.path, headers)  request.set_form_data({   'client_id'     => @client_id,   'client_secret' => @client_secret,   'grant_type'    => 'authorization_code',   'code'          => params[:code] })  response = https.request(request)  render :json => response.body 

thanks in advance help.

• if {"error": "invalid_client"} means sending additional http request header not required validated uber oauth provider server.
  possible reason misspelled request parameter names. (not case)

  solution: need remove authorization header request , try again, i.e. don't send http request headers.

• if have multiple redirect urls defined in uber developers dashboard , making authentication request without 1 keep in mind first url defined in dashboard used:

  if none provided default first redirect uri provided in application's dashboard.

  and if first url doesn't match url used in the authorize step of oauth flow {"error": "access_denied"}

  however, i've noticed error raised if first url matches url sent authorize step, recommend send redirect_uri parameter @ each step of oauth flow.

  solution: need send redirect_uri parameter in request (the same used on authorize step)

• if code inside params[:code] has been used once or has become invalid {"error": "invalid_grant"}

  solution: need redo authorize (first) step in oauth flow obtain new code need exchange access token.