Flask-GraphQL

2.0.1 · active · verified Sun Apr 12

Flask-GraphQL adds GraphQL support to your Flask application, providing an easy way to integrate a GraphQL API endpoint and an optional GraphiQL IDE. The library is currently at version 2.0.1 and has a stable, though not rapid, release cadence, focusing on compatibility with Flask and core GraphQL Python libraries.

Warnings

breaking Flask-GraphQL 2.x is incompatible with `graphql-core` v3.x and `graphene` v3.x due to strict dependency pinning (`graphql-core <3,>=2.1`). Attempting to install or upgrade to `graphql-core` v3.x or `graphene` v3.x will result in dependency conflicts.
Fix: Ensure `graphql-core` is constrained to a 2.x version (e.g., `pip install 'graphql-core<3,>=2.1'`) and `graphene` is constrained to a 2.x version (e.g., `pip install 'graphene<3,>=2.1'`).
gotcha When using Graphene v3 (if you manage to override `graphql-core` incompatibility or are on a future `flask-graphql` version), passing the Graphene `Schema` object directly to `GraphQLView.as_view`'s `schema` parameter is incorrect. You must use the `graphql_schema` attribute of the Graphene `Schema` object.
Fix: Change `schema=my_graphene_schema_instance` to `schema=my_graphene_schema_instance.graphql_schema` if using Graphene v3.
gotcha Enabling batch GraphQL queries requires an additional URL rule definition with `batch=True`. Without this, clients expecting batch query functionality will encounter errors.
Fix: Add a separate `app.add_url_rule` for `/graphql/batch` and set `batch=True` in `GraphQLView.as_view` options, as shown in the quickstart example.
gotcha Flask-GraphQL supports Flask 2.x, but be aware that Flask 2.0 introduced several breaking changes itself, including dropping support for Python 2 and 3.5. Ensure your Python environment and other Flask extensions are compatible with Flask 2.x before upgrading.
Fix: Review Flask 2.0 changelog for breaking changes, ensure Python version is 3.6+ (preferably 3.7+), and update other Flask extensions as needed.

Install

pip install flask-graphql Install latest stable version

Imports

GraphQLView
```
from flask_graphql import GraphQLView
```
The primary class for handling GraphQL requests is directly importable from the top-level package.

Quickstart

This quickstart sets up a basic Flask application with a GraphQL endpoint at `/graphql`. It defines a simple 'hello world' GraphQL query using Graphene and enables the interactive GraphiQL interface for easy testing in the browser. It also demonstrates how to enable batch query support.

import os
from flask import Flask
from flask_graphql import GraphQLView
import graphene

class Query(graphene.ObjectType):
    hello = graphene.String(description='A typical hello world')

    def resolve_hello(self, info):
        # In a real app, 'info' can contain request context, e.g., for auth
        # For this example, we'll just return a string.
        return 'Hello, World!'

schema = graphene.Schema(query=Query)

app = Flask(__name__)
app.add_url_rule(
    '/graphql',
    view_func=GraphQLView.as_view(
        'graphql',
        schema=schema,
        graphiql=True # Enable the GraphiQL IDE for testing
    )
)

# Optional: for adding batch query support (used in Apollo-Client)
app.add_url_rule(
    '/graphql/batch',
    view_func=GraphQLView.as_view(
        'graphql_batch',
        schema=schema,
        batch=True
    )
)

if __name__ == '__main__':
    # Use a secure way to get host/port in production
    host = os.environ.get('FLASK_HOST', '127.0.0.1')
    port = int(os.environ.get('FLASK_PORT', 5000))
    app.run(host=host, port=port)

view raw JSON →