Trouble with CORS preflight request

#1

Hi All,

I am having trouble integrating one of our REST API. When making a POST request from composer I am geting the following error in the test

Error: TypeError: Failed to fetch. Does the server allow CORS?status: undefined


Resource settings for Create record (POST)
-------------------
Resource URL: https://[redacted]/sirocco/sms-voice-demo
Relative path: /send

In our server, we are getting a pre-flight request (OPTIONS) like so:

OPTIONS /sirocco/sms-voice-demo/send?msisdn=124&message=124 HTTP/1.1" 200 0 "https://platform.appgyver.com/builder/applications/111721/pages/1" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36" "-"

And this is the response I am sending to the OPTIONS request

  HTTP/1.1 200 OK
  Server: openresty
  Date: Thu, 23 Jul 2020 10:14:42 GMT
  Content-Type: application/octet-stream
  Content-Length: 0
  Connection: keep-alive
  Access-Control-Allow-Origin: https://platform.appgyver.com
  Access-Control-Allow-Methods: POST, GET, OPTIONS, DELETE
  Access-Control-Max-Age: 86400

Any hint ?

Thanks,
Luis

#2

It’s not necessarily cors issue. I’d suggest you take a look at the requests in browser console and see if it’s truly a cors issue.

#3

Thanks for the hint

Access to fetch at 'https://[redacted]/sirocco/sms-voice-demo/send?msisdn=f&message=f' from origin 'https://platform.appgyver.com' has been blocked by CORS policy: Request header field content-type is not allowed by Access-Control-Allow-Headers in preflight response.

I added this header and everything works now

#4

@Luis_Gasca what did you excatly add to the header (and to which header - do you mean the request header)?

#5

Likely if their backend required headers for authentication, that was the missing header they added. It would depend on your backend and what sort of headers it requires.