Skills

Skill 9 of 14

Apollo Server

Guide for building GraphQL servers with Apollo Server 5.x.

2 minutes · 352 words · 18 sections

Install

$ npx skills add apollographql/skills --skill apollo-server

$ npx skills add apollographql/skills

» /plugin marketplace add apollographql/skills

The first command installs just this skill, by the name in its SKILL.md; the second installs the whole repository.

Apollo Server 5.x Guide

Apollo Server is an open-source GraphQL server that works with any GraphQL schema. Apollo Server 5 is framework-agnostic and runs standalone or integrates with Express, Fastify, and serverless environments.

Quick Start

Step 1: Install

npm install @apollo/server graphql

For Express integration:

npm install @apollo/server @as-integrations/express5 express graphql cors

Step 2: Define Schema

const typeDefs = `#graphql
  type Book {
    title: String
    author: String
  }

  type Query {
    books: [Book]
  }
`;

Step 3: Write Resolvers

const resolvers = {
  Query: {
    books: () => [
      { title: "The Great Gatsby", author: "F. Scott Fitzgerald" },
      { title: "1984", author: "George Orwell" },
    ],
  },
};

Step 4: Start Server

Standalone (Recommended for prototyping):

The standalone server is great for prototyping, but for production services, we recommend integrating Apollo Server with a more fully-featured web framework such as Express, Koa, or Fastify. Swapping from the standalone server to a web framework later is straightforward.

import { ApolloServer } from "@apollo/server";
import { startStandaloneServer } from "@apollo/server/standalone";

const server = new ApolloServer({ typeDefs, resolvers });

const { url } = await startStandaloneServer(server, {
  listen: { port: 4000 },
});

console.log(`Server ready at ${url}`);

Express:

import { ApolloServer } from "@apollo/server";
import { expressMiddleware } from "@as-integrations/express5";
import { ApolloServerPluginDrainHttpServer } from "@apollo/server/plugin/drainHttpServer";
import express from "express";
import http from "http";
import cors from "cors";

const app = express();
const httpServer = http.createServer(app);

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

await server.start();

app.use(
  "/graphql",
  cors(),
  express.json(),
  expressMiddleware(server, {
    context: async ({ req }) => ({ token: req.headers.authorization }),
  }),
);

await new Promise<void>((resolve) => httpServer.listen({ port: 4000 }, resolve));
console.log("Server ready at http://localhost:4000/graphql");

Schema Definition

Scalar Types

Int - 32-bit integer
Float - Double-precision floating-point
String - UTF-8 string
Boolean - true/false
ID - Unique identifier (serialized as String)

Type Definitions

type User {
  id: ID!
  name: String!
  email: String
  posts: [Post!]!
}

type Post {
  id: ID!
  title: String!
  content: String
  author: User!
}

input CreatePostInput {
  title: String!
  content: String
}

type Query {
  user(id: ID!): User
  users: [User!]!
}

type Mutation {
  createPost(input: CreatePostInput!): Post!
}

Enums and Interfaces

enum Status {
  DRAFT
  PUBLISHED
  ARCHIVED
}

interface Node {
  id: ID!
}

type Article implements Node {
  id: ID!
  title: String!
}

Resolvers Overview

Resolvers follow the signature: (parent, args, contextValue, info)

parent: Result from parent resolver (root resolvers receive undefined)
args: Arguments passed to the field
contextValue: Shared context object (auth, dataSources, etc.)
info: Field-specific info and schema details (rarely used)

const resolvers = {
  Query: {
    user: async (_, { id }, { dataSources }) => {
      return dataSources.usersAPI.getUser(id);
    },
  },
  User: {
    posts: async (parent, _, { dataSources }) => {
      return dataSources.postsAPI.getPostsByAuthor(parent.id);
    },
  },
  Mutation: {
    createPost: async (_, { input }, { dataSources, user }) => {
      if (!user) throw new GraphQLError("Not authenticated");
      return dataSources.postsAPI.create({ ...input, authorId: user.id });
    },
  },
};

Context Setup

Context is created per-request and passed to all resolvers.

interface MyContext {
  token?: string;
  user?: User;
  dataSources: {
    usersAPI: UsersDataSource;
    postsAPI: PostsDataSource;
  };
}

const server = new ApolloServer<MyContext>({
  typeDefs,
  resolvers,
});

// Standalone
const { url } = await startStandaloneServer(server, {
  context: async ({ req }) => ({
    token: req.headers.authorization || "",
    user: await getUser(req.headers.authorization || ""),
    dataSources: {
      usersAPI: new UsersDataSource(),
      postsAPI: new PostsDataSource(),
    },
  }),
});

// Express middleware
expressMiddleware(server, {
  context: async ({ req, res }) => ({
    token: req.headers.authorization,
    user: await getUser(req.headers.authorization),
    dataSources: {
      usersAPI: new UsersDataSource(),
      postsAPI: new PostsDataSource(),
    },
  }),
});

Reference Files

Detailed documentation for specific topics:

Resolvers (opens in a new tab) - Resolver patterns and best practices
Context and Auth (opens in a new tab) - Authentication and authorization
Plugins (opens in a new tab) - Server and request lifecycle hooks
Data Sources (opens in a new tab) - RESTDataSource and DataLoader
Error Handling (opens in a new tab) - GraphQLError and error formatting
Troubleshooting (opens in a new tab) - Common issues and solutions

Key Rules

Schema Design

Use ! (non-null) for fields that always have values
Prefer input types for mutations over inline arguments
Use interfaces for polymorphic types
Keep schema descriptions for documentation

Resolver Best Practices

Keep resolvers thin - delegate to services/data sources
Always handle errors explicitly
Use DataLoader for batching related queries
Return partial data when possible (GraphQL’s strength)

Performance

Use @defer and @stream for large responses
Implement DataLoader to solve N+1 queries
Consider persisted queries for production
Use caching headers and CDN where appropriate

Ground Rules

ALWAYS use Apollo Server 5.x patterns (not v4 or earlier)
ALWAYS type your context with TypeScript generics
ALWAYS use GraphQLError from graphql package for errors
NEVER expose stack traces in production errors
PREFER startStandaloneServer for prototyping only
USE an integration with a server framework like Express, Koa, Fastify, Next, etc. for production apps
IMPLEMENT authentication in context, authorization in resolvers

About this skill

Trigger

Guide for building GraphQL servers with Apollo Server 5.x. Use this skill when: (1) setting up a new Apollo Server project, (2) writing resolvers or defining GraphQL schemas, (3) implementing authentication or authorization, (4) creating plugins or custom data sources, (5) troubleshooting Apollo Server errors or performance issues.

The verbatim description from this skill’s front matter — the string an agent matches on to decide whether to load it.

Allowed tools: Bash(npm:*)Bash(npx:*)Bash(node:*)ReadWriteEditGlobGrep
Compatibility: Node.js v20+, TypeScript 4.7+. Works with Express v4/v5, standalone, Fastify, and serverless.
Licence: MIT
Source: skills/apollo-server/SKILL.md

Colophon for this issue

Colophon

How this issue was made

Source

github.com/apollographql/skills, branch main, last pushed 23 September 2026.

Licence

MIT — the text of every skill is reproduced unmodified, frontmatter included, under the upstream licence.

Discovery

14 skills found by walking the repository tree for SKILL.md, not by matching a directory convention. One layout observed: skills/*/SKILL.md.

Issue colours

Resolved from a deterministic hash of the owner name. Two accent tones are generated per issue and each is proven against its own ground before it ships: a single accent that passes AA on both light and dark paper is arithmetically impossible.

Heading repairs

1 repair applied to this skill so the document has one h1 and no skipped levels:

Shifted “18 headings” from h1 to h2 so the skill title is the only h1.

Spec compliance

Every skill satisfies the Agent Skills specification’s frontmatter rules.

Images

Images inside a skill come from the upstream repository. Where the author gave no alternative text we mark the image decorative rather than inventing a description — a plausible caption we made up is worse than none for the reader who depends on it.

Marketplace

A plugin manifest is published at .claude-plugin/marketplace.json by Apollo GraphQL, declaring 1 plugin. It is read for editorial metadata only — never as the skill index, which is always the repository tree.

Signal

Install counts come from skills.sh. They measure downloads, not quality, and an unranked repository is not an unread one.

Agent surfaces

The whole issue is available as one markdown document at /apollographql/skills.md, and each skill at its own .md URL.

Publication

Set by Skills Docs from the source repository. Body text is Literata at the reader’s chosen size and measure; code is Geist Mono. Nothing on this page was written by us except this paragraph.

npm install @apollo/server graphql

For Express integration:

npm install @apollo/server @as-integrations/express5 express graphql cors

Step 2: Define Schema

const typeDefs = `#graphql
  type Book {
    title: String
    author: String
  }

  type Query {
    books: [Book]
  }
`;

Step 3: Write Resolvers

const resolvers = {
  Query: {
    books: () => [
      { title: "The Great Gatsby", author: "F. Scott Fitzgerald" },
      { title: "1984", author: "George Orwell" },
    ],
  },
};

Step 4: Start Server

Standalone (Recommended for prototyping):

import { ApolloServer } from "@apollo/server";
import { startStandaloneServer } from "@apollo/server/standalone";

const server = new ApolloServer({ typeDefs, resolvers });

const { url } = await startStandaloneServer(server, {
  listen: { port: 4000 },
});

console.log(`Server ready at ${url}`);

Express:

import { ApolloServer } from "@apollo/server";
import { expressMiddleware } from "@as-integrations/express5";
import { ApolloServerPluginDrainHttpServer } from "@apollo/server/plugin/drainHttpServer";
import express from "express";
import http from "http";
import cors from "cors";

const app = express();
const httpServer = http.createServer(app);

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

await server.start();

app.use(
  "/graphql",
  cors(),
  express.json(),
  expressMiddleware(server, {
    context: async ({ req }) => ({ token: req.headers.authorization }),
  }),
);

await new Promise<void>((resolve) => httpServer.listen({ port: 4000 }, resolve));
console.log("Server ready at http://localhost:4000/graphql");

Schema Definition

Scalar Types

Int - 32-bit integer
Float - Double-precision floating-point
String - UTF-8 string
Boolean - true/false
ID - Unique identifier (serialized as String)

Type Definitions

type User {
  id: ID!
  name: String!
  email: String
  posts: [Post!]!
}

type Post {
  id: ID!
  title: String!
  content: String
  author: User!
}

input CreatePostInput {
  title: String!
  content: String
}

type Query {
  user(id: ID!): User
  users: [User!]!
}

type Mutation {
  createPost(input: CreatePostInput!): Post!
}

Enums and Interfaces

enum Status {
  DRAFT
  PUBLISHED
  ARCHIVED
}

interface Node {
  id: ID!
}

type Article implements Node {
  id: ID!
  title: String!
}

Resolvers Overview

Resolvers follow the signature: (parent, args, contextValue, info)

parent: Result from parent resolver (root resolvers receive undefined)
args: Arguments passed to the field
contextValue: Shared context object (auth, dataSources, etc.)
info: Field-specific info and schema details (rarely used)

const resolvers = {
  Query: {
    user: async (_, { id }, { dataSources }) => {
      return dataSources.usersAPI.getUser(id);
    },
  },
  User: {
    posts: async (parent, _, { dataSources }) => {
      return dataSources.postsAPI.getPostsByAuthor(parent.id);
    },
  },
  Mutation: {
    createPost: async (_, { input }, { dataSources, user }) => {
      if (!user) throw new GraphQLError("Not authenticated");
      return dataSources.postsAPI.create({ ...input, authorId: user.id });
    },
  },
};

Context Setup

Context is created per-request and passed to all resolvers.

interface MyContext {
  token?: string;
  user?: User;
  dataSources: {
    usersAPI: UsersDataSource;
    postsAPI: PostsDataSource;
  };
}

const server = new ApolloServer<MyContext>({
  typeDefs,
  resolvers,
});

// Standalone
const { url } = await startStandaloneServer(server, {
  context: async ({ req }) => ({
    token: req.headers.authorization || "",
    user: await getUser(req.headers.authorization || ""),
    dataSources: {
      usersAPI: new UsersDataSource(),
      postsAPI: new PostsDataSource(),
    },
  }),
});

// Express middleware
expressMiddleware(server, {
  context: async ({ req, res }) => ({
    token: req.headers.authorization,
    user: await getUser(req.headers.authorization),
    dataSources: {
      usersAPI: new UsersDataSource(),
      postsAPI: new PostsDataSource(),
    },
  }),
});

Reference Files

Detailed documentation for specific topics:

Resolvers (opens in a new tab) - Resolver patterns and best practices
Context and Auth (opens in a new tab) - Authentication and authorization
Plugins (opens in a new tab) - Server and request lifecycle hooks
Data Sources (opens in a new tab) - RESTDataSource and DataLoader
Error Handling (opens in a new tab) - GraphQLError and error formatting
Troubleshooting (opens in a new tab) - Common issues and solutions

Key Rules

Schema Design

Use ! (non-null) for fields that always have values
Prefer input types for mutations over inline arguments
Use interfaces for polymorphic types
Keep schema descriptions for documentation

Resolver Best Practices

Keep resolvers thin - delegate to services/data sources
Always handle errors explicitly
Use DataLoader for batching related queries
Return partial data when possible (GraphQL’s strength)

Performance

Use @defer and @stream for large responses
Implement DataLoader to solve N+1 queries
Consider persisted queries for production
Use caching headers and CDN where appropriate

Ground Rules

ALWAYS use Apollo Server 5.x patterns (not v4 or earlier)
ALWAYS type your context with TypeScript generics
ALWAYS use GraphQLError from graphql package for errors
NEVER expose stack traces in production errors
PREFER startStandaloneServer for prototyping only
USE an integration with a server framework like Express, Koa, Fastify, Next, etc. for production apps
IMPLEMENT authentication in context, authorization in resolvers

About this skill

Trigger

Colophon

Appendix 9.1–9.6

ReferencesMarkdown · 6 files

About this skill

Trigger

Colophon

Appendix 9.1–9.6

ReferencesMarkdown · 6 files