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Ariadne

Ariadne is a Python library for implementing GraphQL servers.

• Schema-first: Ariadne enables Python developers to use schema-first approach to the API implementation. This is the leading approach used by the GraphQL community and supported by dozens of frontend and backend developer tools, examples, and learning resources. Ariadne makes all of this immediately available to your and other members of your team.
• Simple: Ariadne offers small, consistent and easy to memorize API that lets developers focus on business problems, not the boilerplate.
• Open: Ariadne was designed to be modular and open for customization. If you are missing or unhappy with something, extend or easily swap with your own.

Documentation is available here.

Features

• Simple, quick to learn and easy to memorize API.
• Compatibility with GraphQL.js version 14.2.1.
• Queries, mutations and input types.
• Asynchronous resolvers and query execution.
• Subscriptions.
• Custom scalars and enums.
• Unions and interfaces.
• Defining schema using SDL strings.
• Loading schema from .graphql files.
• WSGI middleware for implementing GraphQL in existing sites.
• Opt-in automatic resolvers mapping between camelCase and snake_case.
• Build-in simple synchronous dev server for quick GraphQL experimentation and GraphQL Playground.
• Support for Apollo GraphQL extension for Visual Studio Code.
• GraphQL syntax validation via gql() helper function. Also provides colorization if Apollo GraphQL extension is installed.
• No global state or object registry, support for multiple GraphQL APIs in same codebase with explicit type reuse.

Installation

Ariadne can be installed with pip:

pip install ariadne

Quickstart

The following example creates an API defining Person type and single query field people returning a list of two persons. It also starts a local dev server with GraphQL Playground available on the http://127.0.0.1:8000 address.

Start by installing uvicorn, an ASGI server we will use to serve the API:

pip install uvicorn

Then create an example.py file for your example application:

from ariadne import ObjectType, QueryType, gql, make_executable_schema
from ariadne.asgi import GraphQL

# Define types using Schema Definition Language (https://graphql.org/learn/schema/)
# Wrapping string in gql function provides validation and better error traceback
type_defs = gql("""
    type Query {
        people: [Person!]!
    }

    type Person {
        firstName: String
        lastName: String
        age: Int
        fullName: String
    }
""")

# Map resolver functions to Query fields using QueryType
query = QueryType()

# Resolvers are simple python functions
@query.field("people")
def resolve_people(*_):
    return [
        {"firstName": "John", "lastName": "Doe", "age": 21},
        {"firstName": "Bob", "lastName": "Boberson", "age": 24},
    ]


# Map resolver functions to custom type fields using ObjectType
person = ObjectType("Person")

@person.field("fullName")
def resolve_person_fullname(person, *_):
    return "%s %s" % (person["firstName"], person["lastName"])

# Create executable GraphQL schema
schema = make_executable_schema(type_defs, [query, person])

# Create an ASGI app using the schema, running in debug mode
app = GraphQL(schema, debug=True)

Finally run the server:

uvicorn example:app

For more guides and examples, please see the documentation.

Contributing

We are welcoming contributions to Ariadne! If you've found a bug or issue, or if you have any questions or feedback, feel free to use GitHub issues.

For guidance and instructions, please see CONTRIBUTING.md.

Crafted with ❤️ by Mirumee Software hello@mirumee.com