michael-groble / juniper

GraphQL server library for Rust

GraphQL server library for Rust

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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 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 Actix, Hyper, Iron, Rocket, and Warp frameworks, including embedded Graphiql and GraphQL Playground for easy debugging.

• Cargo crate
• API Reference
• Book: Guides and Examples (current | master)

The book is also available for the master branch and older versions published after 0.11.1. See the book index.

Getting Started

The best place to get started is the Juniper Book, which contains guides with plenty of examples, covering all features of Juniper. (very much WIP)

To get started quickly and get a feel for Juniper, check out the Quickstart section.

For specific information about macros, types and the Juniper api, the API Reference is the best place to look.

You can also check out the Star Wars schema to see a complex example including polymorphism with traits and interfaces. For an example of web framework integration, see the actix, hyper, rocket, iron, and warp examples folders.

Features

Juniper supports the full GraphQL query language according to the specification (October 2021), including interfaces, unions, schema introspection, and validations. It can also output the schema in the GraphQL 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>>>.

Juniper is agnostic to serialization format and network transport.

Juniper supports both asynchronous and synchronous execution using execute() and execute_sync() respectively. Asynchronous execution is runtime agnostic.

Juniper follows a code-first approach to defining GraphQL schemas. If you would like to use a schema-first approach instead, consider juniper-from-schema for generating code from a schema file.

Integrations

Data types

Juniper has automatic integration with some very common Rust crates to make building schemas a breeze. The types from these crates will be usable in your Schemas automatically.

• uuid
• url
• chrono
• chrono-tz
• time
• bson

Web Frameworks

• actix
• hyper
• rocket
• iron
• warp

Guides & Examples

• Juniper + actix-web example

API Stability

Juniper has not reached 1.0 yet, thus some API instability should be expected.