what is SubscribePayload.extensions for?

[jjangga0214]

I looked around source code, but couldn't find how SubscribePayload.extensions is practically used.

Is it something like context, but not implemented yet?

Thanks :)

[enisdenjo]

*Converted to a Q&A discussion

The extensions field is reserved for implementors to extend the protocol however they see fit. Through it you can pass extra values to the GraphQL operation for custom behaviour, one example being: persisted queries.

[enisdenjo]

FYI, I've changed the "ws server and client usage with persisted queries" recipe to showcase the convention of using the extensions field.