Chirpstack 4 grpc with grpcurl

Hello,

i'd like to automate some things via bash scripts. My goto tool in this case is "grpcurl".

My server runs in docker (chirpstack/chirpstack:4.15).

The following command:

grpcurl -import-path "$PROTO_PATH" \
        -proto as/external/api/organization.proto \
        "$CHIRPSTACK_API_URL" list

returns:

api.OrganizationService

Am i right to assume that grpc communication is wokring?

The next command:

grpcurl -d "$(cat <<EOF
{
  "organization": {
    "name": "$TENANT_NAME",
    "display_name": "$TENANT_DESC",
    "can_have_gateways": true
  }
}
EOF
)" \
-H "Authorization: Bearer $CHIRPSTACK_API_TOKEN" \
-import-path "$PROTO_PATH" \
-proto as/external/api/organization.proto \
"$CHIRPSTACK_API_URL" api.OrganizationService.Create

}

fails with the message:

ERROR:
  Code: Unimplemented
  Message:

Now i have tried some variations, including one that suggested "api.OrganizationService/Create" but none of the commands worked.

Am i missing something?