SAML logout without browser (cookies)

Good morning,

I’m trying to make SAML logout from SP, but without browser involved, e.g. there is no IdP cookies sent in request. I have background thread on server side that delete local session on timeout and I want to end IdP session as well.

Wonder if it’s possible at all with KeyCloak. I use version 15.0.2.

If I try to send same GET request that I use in redirect, it fails with 400 error (Invalid Request) - I assume no cookies makes it imposible to authenticate such request on the KeyClock side. Is it possible to sign request to make it works?

Attempt to POST same samlp:LogoutRequest fails with unsupported content type - looks like it expect JSON only.