graphql-subscriptions VS express-graphql

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

It looked a little janky but it actually worked fine. But then I needed file uploads. Something graphql-zeus does not support. So I had to create a small wrapper for the SDK created so that it worked. And then also express-graphql, the server I was using, was deprecated.

This seems like a minor deal unless you're not using Express as your web framework. And an important note here is that Express GraphQL is being deprecated by the GraphQL Foundation. So if you're using Express for a GraphQL API, you should move away from it anyway.

You might have seen other GraphQL server solutions where the schema is implemented by using a more programmatic approach. Here is an example of how schemas are implemented using the express-graphql library. (link: https://github.com/graphql/express-graphql)

I'm not sure where the "8MB limit" comes from but, indeed, there are issues like this where, in some implementations, the response size is limited to 100KB: https://github.com/graphql/express-graphql/issues/346

With Node I used express-graphql as opposed to something like Apollo because it's lighter and less heavy on resources compared to Apollo.

Daniel Rearden listed the following reasons pushing him to create Helix, believing that these factors were absent from popular solutions like Apollo Server, express-graphql and Mercurius:

Express GraphQL is a library for building production ready GraphQL HTTP middleware. Despite the emphasis on Express in the repo name, you can create a GraphQL HTTP server with any HTTP web framework that supports connect styled middleware. This includes Connect itself, Express and Restify.

If you are using Node.js there are a lot of implementations of GraphQL servers with a few being express-graphql, apollo-server, mercurius, graphql-helix and more. And if you are using other languages, you can see a great list here

express-graphql GitHub Repository

Not sure about other libraries but it's certainly not the case for express-graphql on node.js. You can tie the graphql endpoint to any method you like. On the site I work on, we have a graphql endpoint that only accepts GET requests in production and is thus cacheable by Cloudfront. In dev and staging we accept all requests so that GraphIQL works.