graphql-playground VS graphql-subscriptions

graphql-yoga is built on other packages that provide functionality required for building a GraphQL server such as web server frameworks like express and apollo-server, GraphQL subscriptions with graphql-subscriptions and subscriptions-transport-ws, GraphQL engine & schema helpers including graphql.js and graphql-tools, and an interactive GraphQL IDE with graphql-playground.

graphql-yoga is built on other packages that provide functionality required for building a GraphQL server such as web server frameworks like express and apollo-server, GraphQL subscriptions with graphql-subscriptions and subscriptions-transport-ws, GraphQL engine & schema helpers including graphql.js and graphql-tools, and an interactive GraphQL IDE with graphql-playground.

The most common used (but not best maintained) library for such a PubSub engine in the GraphQL context is graphql-subscriptions. There are also adapters available for more distributed systems (where all GraphQL API replicas must be notified about the event) e.g. over Redis.

During that work, we created and merged the reference implementation into graphql-js and created two supporting libraries: graphql-subscriptions and subscriptions-transport-ws. Here is a talk with deep dive into all the details.

The Prisma / GraphQL-Yoga comes with Subscriptions, and this was the first thing I came across when my client asked for realtime updates. The implementation was quite difficult - took me a long time. Eventually, it was working locally, and in staging. However, when it came to the production environment, for some reason it just didn't work! This unfortunately ended up with a user losing an auction, which ultimately went to court etc.

There are also other solutions available: https://github.com/apollographql/graphql-subscriptions#pubsub-implementations

First, let's try to understand what PubSub is exactly. Apollo Server uses a publish-subscribe (pub/sub) model to track events that update subscriptions. The graphql-subscriptions library included in all apollo-server packages (including middleware integrations) provides a PubSub class as a basic in-memory event bus.

To add this, I can just expand the basic setup above. To do so, I do actually use a couple of small Apollo modules! Most can be picked and configured independently. For this case, graphql-subscriptions provides a little bit of pubsub logic that works within resolvers, and subscriptions-transport-ws integrates that into Express to handle the websockets themselves. Super helpful