graphql-sse VS graphql-over-http

The GraphQL over SSE in its simplest form IMHO does not require an additional client library. Setting up a subscription in the browser is as simple as doing the following:

There is already a JavaScript implementation for server + client with support for multiplexing from the same maintainer of graphql-ws: graphql-sse

Actually WebSocket is not the only protocol for executing GraphQL subscriptions. There is also a graphql-over-sse protocol, which is much more lightweight, and uses Server Sent Events. A popular implementation of it is the graphql-sse library, which is maintained by the same person as graphql-ws. The setup and API of both libraries is pretty similar.

graphql-sse is a reference implementation of the GraphQL over Server-Sent Events Protocol aiming to become a part of the GraphQL over HTTP standard.

Another major pain is the fact that operation names and HTTP codes are often hidden in request bodies which makes it really hard to see what is going on in standard monitoring tools. It's possible to write some converter but it's beyond me why some people decided that requests which failed on the server respond with status 200. GraphQL spec doesn't define how it should behave, there's only a proposal (https://github.com/graphql/graphql-over-http)

The GraphQL over HTTP specification states the following:

However, if you are doing GraphQL subscriptions over Server Sent Events (HTTP) (which is currently not part of the GraphQL over HTTP specification), the data flow is only from server to client. So each operation must be a separate request, which should be no problem when using HTTP/2, as the browser connection limit is not hit so fast (There are also workarounds to this if you cannot ise HTTP/2).

Complementary to the note, you can learn more about GraphQL over HTTP in the specification over here: https://github.com/graphql/graphql-over-http/blob/main/spec/GraphQLOverHTTP.md

GraphQL-spec, GraphQL-over-HTTP: guarantees your GraphQL API to work with all existing GraphQL clients (Apollo, Relay, URQL, and more).

Note: While GraphQL can be done over almost any protocol, this article focuses on the most commonly used protocol GraphQL over HTTP. However, most knowledge can be transferred to other protocols such as GraphQL over WebSockets or other more exotic ones.

There is also the GraphQL over HTTP Specification repository https://github.com/graphql/graphql-over-http

graphql-sse is a reference implementation of the GraphQL over Server-Sent Events Protocol aiming to become a part of the GraphQL over HTTP standard.

With no further ado - I humbly introduce graphql-ws. A coherent, feature-full, zero-dependency, plug-n-play, lazy, simple, server and client implementation of the new, security first GraphQL over WebSocket Protocol with full support for all 3 GraphQL operations: Queries, Mutations and Subscriptions. The protocol aims to be standardised and become a part of GraphQL with the help of the foundation’s GraphQL over HTTP work group.

You could additionally also choose a specific HTTP code for that scenario (although that would contradict the official GraphQL over HTTP spec https://github.com/graphql/graphql-over-http/blob/main/spec/GraphQLOverHTTP.md).