Invalid_client error when generating access token from signed jwt

[shivani puram]

Hi all,

I am getting invalid_client (400) error when invoking https://fhir.epic.com/interconnect-fhir-oauth/oauth2/token with signed jwt token.

My expiration claim has the right value and non-production-client is active on the epic sandbox.

How can I resolve this issue and is there a way I can find which parameter in the jwt is causing the error.

Thanks,

Shivani

[Noval Agung Prayogo]

Hi Shivani, do you have the solution already?
I am currently facing the same error. I'm pretty sure my jwt token is valid and it has expiration duration under 5 minutes, but still I get `invalid_client` whenever trying to get the token

Appreciate the help

[Jack Neil]

Same here. Posting to  https://fhir.epic.com/interconnect-fhir-oauth/oauth2/token

I've checked my jwt on jwt.io and checked that the public key validates the signature there as well. Setting the exp to 4 minutes in the future and checked the relative timestamp at epochconverter.com to make sure there isn't a timezone issue. Generating a new random 16 character jti on each request. Made sure to post the params into the post body. Uploaded the public jwt key to the epic sandbox nearly 48 hours ago now. 

Still getting 'invalid_client' every time. 

Anyone else have any thoughts?