Why can I not reach my localhost?
This tool cannot access localhost, or any endpoint behind your firewall or VPN, because it runs on the internet rather than on your computer. To reach one, sign in to Postman and use either the Postman Desktop App or the Desktop Agent in the web app. Both run on your own machine: the request goes straight from your computer to your endpoint, and your request data and credentials never pass through Postman's cloud.
Can the playground use server reflection?
Yes. Enter a server URL, open Service definition, and choose Use Server Reflection.
Can I import protobuf files?
Yes. Import a local .proto file from the Service definition tab.
Does the playground load Postman workspaces or variables?
No. It does not load workspace, collection, environment, history, variable, Spec Hub, or account state.