I have figured this out, but with a caveat that makes me think this could be improved. https://github.com/supertokens/supertokens-node/blob/db2588234df431959afa65546fc8db717dbd17fe/lib/build/recipe/thirdparty/providers/google.d.ts#L8-L10 I noticed that the

TypeThirdPartyProviderGoogleConfig['authorisationRedirect']['params']

in the config could be a function that gets the request instead of a string, so I used that.

ts
          ThirdPartyEmailPassword.Google({
            clientId: config.clientId,
            clientSecret: config.clientSecret,
            scope: [ ... ],
            authorisationRedirect: {
              params: {
                login_hint: (request: any) => {
                  const params = new URLSearchParams(request.url)
                  const someParam = params.get('someParam')
                  
                  if(someParam){
                    return someParam
                  }
                  
                  // dont want to return anything here
                  return ''
                }
              }
            }
          })

The problem is that I only want to set the

login_hint

sometimes (when the parameter is added to the request). But currently I am forced to always set it or never set it. I see 2 ways this could be addressed: 1. The keys of

TypeThirdPartyProviderGoogleConfig['authorisationRedirect']['params']

(and the other provider configs) could be changed to return a string or undefined, then the keys with undefined values could be filtered out. This was my first instinct. 2.

TypeThirdPartyProviderGoogleConfig['authorisationRedirect']['params']

type could be expanded to also include a function with the request passed in which returns

params

(similar to the keys on params which I utilized above). Is there currently another workaround for this issue? Would you be open to a pull request implementing either of these?

Again, this brings up my original question: can the config be modified in the

thirdPartySignInUpPOST

hook? If so, that would be another way to solve this problem.

I'll check this out in more detail tomorrow, meanwhile: - this may be worth checking out: https://supertokens.com/docs/thirdparty/common-customizations/sign-in-and-up/custom-providers - we are always open to PRs 🙂

1. Override

authorisationUrlGET

, call the original implementation and then append

login_hint

param to the url (whenever you need it) and return it. 2. In the method you are currently doing which forces you to send a value, you could return empty string instead of undefined in cases you don't need it. the google provider will ignore it.