Async-graphql is a GraphQL server-side library implemented in Rust. It is fully compatible with the GraphQL specification and most of its extensions, and offers type safety and high performance.
You can define a Schema in Rust and procedural macros will automatically generate code for a GraphQL query. This library does not extend Rust’s syntax, which means that Rustfmt can be used normally. I value this highly and it is one of the reasons why I developed Async-graphql.
Juniper is a GraphQL server library for Rust. Build type-safe and fast API servers with minimal boilerplate and configuration.
GraphQL is a data query language developed by Facebook intended to serve mobile and web application frontends.
Juniper makes it possible to write GraphQL servers in Rust that are type-safe and blazingly fast. We also try to make declaring and resolving GraphQL schemas as convenient as possible as Rust will allow.
Juniper does not include a web server - instead it provides building blocks to make integration with existing servers straightforward. It optionally provides a pre-built integration for the Hyper, Iron, Rocket, and Warp frameworks, including embedded Graphiql for easy debugging.
Juniper supports the full GraphQL query language according to the specification (October 2021), including interfaces, unions, schema introspection, and validations. It does not, however, support the schema language.
As an exception to other GraphQL libraries for other languages, Juniper builds non-null types by default. A field of type Vec\<Episode\> will be converted into \[Episode!\]!. The corresponding Rust type for e.g. \[Episode\] would be Option\<Vec\<Option\<Episode\>\>\>.