Note: this repo has been archived. For Apollo Server v4, our intention was to publish this package separately. We have since decided to no longer support the idea of a DataSource interface at all, since it's a very light abstraction that isn't really necessary. For more details, see apollographql/apollo-server#6047
The @apollo/datasource package exports an abstract class to be implemented by DataSource authors. An implementation of a DataSource is simply a means for fetching data. Aside from the initialize function (used to provide cache and context objects), ApolloServer is agnostic to how a DataSource is used and how it goes about fetching data.
Visit the documentation for information on how DataSources are used and implemented.