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 Iron and Rocket frameworks, including embedded Graphiql for easy debugging.
The best place to get started is the Juniper Book, which contains guides with plenty of examples, covering all features of Juniper.
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 src/tests/schema.rs to see a complex schema including polymorphism with traits and interfaces. For an example of web framework integration, see the rocket and iron examples folders.
Juniper supports the full GraphQL query language according to the specification, 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
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.
Juniper has not reached 1.0 yet, thus some API instability should be expected.
pub use crate::executor::Context;
pub use crate::executor::ExecutionError;
pub use crate::executor::ExecutionResult;
pub use crate::executor::Executor;
pub use crate::executor::FieldError;
pub use crate::executor::FieldResult;
pub use crate::executor::FromContext;
pub use crate::executor::IntoFieldError;
pub use crate::executor::IntoResolvable;
pub use crate::executor::Registry;
pub use crate::executor::ValuesStream;
pub use crate::executor::Variables;
Resolve the document to values
Utilities for building HTTP endpoints in a library-agnostic manner
Provides GraphQLType implementations for some external types
Marker traits for GraphQL types.
Types used to describe a
Query parser and language utilities
Query validation related methods and data structures
Construct JSON-like values by using JSON syntax
Field argument container
Utility type to define read-only schemas
Utillity type to define read-only schemas
Represents the result of executing a GraphQL operation (after parsing and validating has been done).
An ID as defined by the GraphQL specification
An argument passed into the query
A selection performed by a query
A Object value
Root query node of a schema
Query validation error
Metadata for a schema
Data structure used to wrap items with start and end markers in the input source
An enum that describes if a field is available in all types of the interface or only in a certain subtype
The default scalar value representation in juniper
An error that prevented query execution
A JSON-like value that can be passed into the query execution, either out-of-band, or in-band as default variable values. These are not constant and might contain variables.
The desired GraphQL introspection format for the canonical query (https://github.com/graphql/graphql-js/blob/8c96dc8276f2de27b8af9ffbd71a4597d483523f/src/utilities/introspectionQuery.js#L21)
A JSON-like value that can is used as argument in the query execution
Nullable can be used in situations where you need to distinguish between an implicitly and
explicitly null input value.
Error while parsing a GraphQL query
Entry in a GraphQL selection set
A type literal in the syntax tree
GraphQL type kind
Serializable value returned from query and field execution.
This trait is used in
juniper::graphql_subscription macro to get stream’s
item type that implements
GraphQLValue from type alias provided
Parse an unstructured input value into a Rust data type.
Maker trait for GraphQL interfaces.
Primary trait used to expose Rust types in a GraphQL schema.
GraphQLType trait with asynchronous queries/mutations resolvers.
Maker trait for GraphQL unions.
Primary trait used to resolve GraphQL values.
GraphQLValue trait with asynchronous queries/mutations resolvers.
Set of common methods for
A trait used to convert a
ScalarToken into a certain scalar value type
A trait marking a type that could be used as internal representation of scalar values in juniper
Single subscription connection.
Global subscription coordinator trait.
Losslessly clones a Rust data type into an InputValue.
Execute a query in a provided schema
Execute a query synchronously in a provided schema
Execute the reference introspection query in the provided schema
Resolve subscription into
An owned dynamically typed
Future for use in cases where you can’t
statically type your result or need to add some indirection.
BoxFuture, but without the
The result of converting a string into a scalar value
#[graphql_interface] macro for generating a GraphQL interface implementation for traits
and its implementers.
object proc macro is the primary way of defining GraphQL resolvers
that can not be implemented with the GraphQLObject derive.
Expose GraphQL scalars
A proc macro for defining a GraphQL subscription.
#[graphql_union] macro for deriving a GraphQL union implementation for traits.