GraphQL Playground Middleware for Express

Express middleware that exposes the GraphQL Playground IDE (an interactive GraphQL client with introspection, subscriptions, and documentation) as a route in your Express server. Current stable version is 1.7.23, with infrequent releases. Key differentiator: more feature-rich than GraphiQL, offering subscription support, theming, and collapsible docs. Alternatives: graphiql-express, altair-express. Note: versions before 1.7.16 had a security vulnerability when passing unsanitized user input to expressPlayground().