Node.js oAuth - unsupported_grant_type on Step 4

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1

Hello,

I am trying to implement the oAuth2 flow using Node.js to enable my users to connect their Patreon account to my site to prove they are indeed paying. I am following the oAuth implementation guide but at step 4 the only response I get from the API is

{ error: 'unsupported_grant_type' }

My code is

const response = await fetch("https://www.patreon.com/api/oauth2/token", {
    method: "POST",
    headers: { "Content-Type": "application/x-www-form-encoded" },
    body:
      "code=" +
      code +
      "&grant_type=authorization_code&client_id=" +
      PA_APP_ID +
      "&client_secret=" +
      PA_APP_SECRET +
      "&redirect_url=" +
      PA_CALLBACK,
  });

All the variables are set correctly and according to the docs the required grant type is indeed “authorization_code”. So … what am I doing wrong? I have done several other oAuth implementations and this is the only time an API gives me a headache.

Thanks, Richard

2

Can you try adding a user-agent header to the call…

3

I just tried that and it didn’t change anything, unfortunately.

4

Are you using a v2 client? Are you calling v2 endpoints?