graphql_api

GraphQL API Example

A simple GraphQL API built with the Vania framework and vania_graphql. Open the endpoint in a browser and you get the GraphiQL web IDE (like the Apollo Sandbox) to explore and run queries.

The schema

type Book { id: Int, title: String, author: String }

type Query {
  hello: String
  books: [Book]
  book(id: Int!): Book
}

It resolves against an in-memory list of books — see lib/graphql/schema.dart. The whole app is wired in config/app.dart with a single provider:

GraphQLServiceProvider(schema: buildSchema())

That registers one route that answers both GET and POST at /graphql.

Open the IDE

Start the server and open the endpoint in a browser:

dart pub get
dart run bin/server.dart

→ http://localhost:8000/graphql

A browser sends Accept: text/html, so the endpoint returns the GraphiQL IDE. Try:

{
  books { id title author }
  book(id: 2) { title }
}

Programmatic clients POST instead:

curl -X POST http://localhost:8000/graphql \
  -H 'Content-Type: application/json' \
  -d '{"query":"{ books { title } }"}'

Enabling the IDE (important)

GraphiQL and introspection are off in production by default — they publish your whole schema. The switch is APP_ENV, not APP_DEBUG:

• isProduction = env('APP_ENV', 'production') == 'production'
• graphiqlEnabled / introspectionEnabled default to !isProduction

So this example's .env sets APP_ENV=local. Without it, GET /graphql returns JSON errors instead of the IDE. (APP_DEBUG=true alone does not enable it.) To serve the IDE in a production environment on purpose, set GRAPHQL_GRAPHIQL_ENABLED=true and GRAPHQL_INTROSPECTION_ENABLED=true explicitly.

Tests

The schema is executed in-process, no server needed:

dart test