"Test Connection" fails for very basic gRPC configuration, grpcui works

I'm trying out retool and wanted to try out the gRPC connection but keep getting a

Test connection failed
Error: 14 UNAVAILABLE: No connection established

Its the most basic setup

  • Host is the server's domain - no scheme, no port, just a domain name
  • Port is 443
  • Service definition using reflection
  • No metadata
  • No authentication
  • Enable SSL/TLS with full verification

For comparison, with grpcui <host>:443 I get a working grpcui (which uses reflection) and can send a grpc.health.v1.Health/Check request and receive a response.

What might be going wrong? What else can I check?

Hey @nev.sensat! How is the certificate for your gRPC server managed and how have you configured it in Retool?