shell> curl -X POST --data-binary @- --dump - http://localhost:8529/_api/transaction
{ 
  "collections" : { 
    "read" : "products" 
  }, 
  "action" : "function () { return true; }" 
}

HTTP/1.1 404 Not Found
content-type: application/json; charset=utf-8

{ 
  "exception" : "[ArangoError 1203: collection not found]", 
  "stacktrace" : [ 
    "Error: collection not found", 
    "  at Error (native)", 
    "  at post_api_transaction (js/actions/api-transaction.js:268:16)", 
    "  at Function.actions.defineHttp.callback (js/actions/api-transaction.js:288:11)", 
    "" 
  ], 
  "error" : true, 
  "code" : 404, 
  "errorNum" : 1203, 
  "errorMessage" : "collection not found" 
}