Subscriptions in graphQL mesh

[sesmi123]

Hi,

I have a graphql mesh acting as gateway for multiple services, one of which is a graphql service having subscription type. I am able to subscribe successfully from the graphiql mesh client. But I noticed that the subscription from graphiql mesh is working on http SSE streaming and not using websockets.

I need to subscribe to the query from an angular app. I am using apollo client for angular and it is using websockets by default. I tried using graphql-sse but it didnt work for me either. Could you please guide me on how subscriptions can me made to mesh from angular client?

Thanks

[sesmi123]

I could subscribe to it by using SSE implementation in angular. Just in case anyone need reference: Angular and Server Sent Events (SSE)

[ardatan]

Do you think we can improve the documentation by pointing this out?

[sesmi123]

Yes, I think it would be a nice addition to specify the protocol used for subscriptions in the documentation. Personally, I was stuck for a while trying to subscribe from the client using websockets protocol.

[ardatan]

I see I created an issue for that;
#4089
Maybe you were trying the old protocol instead of this one?
https://github.com/enisdenjo/graphql-ws

[sesmi123]

Yes I use the old websocket protocol for my graphql service, but I was able to make it work by configuring the mesh as subscriptionsProtocol: LEGACY_WS. It is clearly documented, thankyou.
I am not very confident, but as per my understanding the communication is something like this:

I don't know if I missed it in the docs or if I'm wrong, but the mesh establishes subscriptions and live queries through SSE.

PS: In the context of improving documentation, in the sample given for file upload, extend Mutation should be extend type Mutation right?

[ardatan]

Mesh is able to receive subscription requests via both WS and SSE. If WS doesn't work, this is definitely a bug.
Yes you're right it should be extend type It is a typo :)