Slack Trustelem Configuration Enter the value of your slack sub-domain in the corresponding field on Trustelem. For example for mydomain.slack.com, enter mydomain Slack Configuration Log in your Slack workspace Click on the drop-down menu then Parameters and administration -> Workspace parameters Click on the Authentication tab and setup SAML Authentication. Paste the following URL in the SAML 2.0 Endpoint (HTTP) field. https://mydomain.trustelem.com/app/33XXXX/sso Paste the following URL in the Identity Provider Issuer field. https://mydomain.trustelem.com/app/33XXXX Paste the certificate into the Public Certificate field $cert = "MIIDXXX...XXXNTYw==" In Advanced Options click on expand Disable Sign In the field AuthnContextClassRef change to Don't send this value In the field Service Provider Issuer let the default url https://slack.com Enable Responses Signed and Assertions Signed Click on Save Configuration