Apollo Server plugins — lifecycle hooks for logging, tracing, and custom logic

Cross-cutting concerns like request logging, error reporting, and performance tracing are copy-pasted into resolvers or middleware. There's no clean way to hook into GraphQL-specific lifecycle events from Express middleware.

Write Apollo Server plugins to hook into GraphQL lifecycle events.

import { ApolloServerPlugin, GraphQLRequestListener } from '@apollo/server';

const loggingPlugin: ApolloServerPlugin = {
  async requestDidStart(requestContext) {
    const start = Date.now();
    console.log(`[GQL] ${requestContext.request.operationName ?? 'anonymous'}`);

    return {
      async didEncounterErrors({ errors }) {
        errors.forEach(e => console.error('[GQL Error]', e.message, e.extensions));
      },
      async willSendResponse() {
        console.log(`[GQL] completed in ${Date.now() - start}ms`);
      },
    };
  },
};

const server = new ApolloServer({
  typeDefs,
  resolvers,
  plugins: [loggingPlugin, ApolloServerPluginUsageReporting()],
});

Plugins have access to GraphQL-specific context (operation name, variables, errors) that HTTP middleware cannot see. They compose cleanly and can be extracted into packages.

Adding logging, monitoring, or custom behaviour to Apollo Server request handling