GraphiQL

GraphiQL is an interactive in-browser GraphQL IDE. This is a fantastic developer tool to help you form queries and explore your Schema.

graphiql

The easiest way to add GraphiQL into your ASP.NET Core app is to use the GraphQL.Server.Ui.GraphiQL package. All you need to do after installing nuget is to append one extra line in your Startup.cs:

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseGraphiQLServer();
}

If you do not explicitly specify an endpoints through the optional options argument then GraphiQL by default will run on /graphiql endpoint and will send requests to /graphql GraphQL API endpoint.

You may find GraphiQL example in graphql-dotnet repo. This ASP.NET Core sample project also provides an example of hosting the GraphiQL IDE with a little more effort.