Apollo Federation

What it does

When your agent uses it

• Creating new subgraph schemas for a federated supergraph
• Modifying entities with @key
• Sharing types/fields across subgraphs with @shareable
• Working with federation directives (@external

Example prompts

• “/apollo-federation”

Requirements

• Compatibility (from SKILL.md): Works with any Federation 2.x compatible subgraph library (Apollo Server, GraphQL Yoga, etc.)
• Pre-approved tools (allowed-tools): Bash(rover:*), Read, Write, Edit, Glob, Grep

What it can do on your machine

Read from SKILL.md and the folder at commit 5f02fcf. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Bash(rover:*)
  • Read
  • Write
  • Edit
  • Glob
  • Grep

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are graphql).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • specs.apollo.dev

  Also links to:

  • apollographql.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Works with any Federation 2.x compatible subgraph library (Apollo Server, GraphQL Yoga, etc.)

  From compatibility in the SKILL.md frontmatter.

Context cost

Apollo Federation loads about 1k tokens when it runs, and up to ~9.7k if it reads all its reference files. Until then it costs about 115 tokens; SKILL.md has 260 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~115

When it runs · the whole SKILL.md, loaded when a task matches

~1k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~9.7k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from apollographql/skills at commit 5f02fcf, republished under its MIT licence (© apollographql). 260 words, ~1,009 tokens.

name

apollo-federation

description

Guide for authoring Apollo Federation subgraph schemas. Use this skill when: (1) creating new subgraph schemas for a federated supergraph, (2) defining or modifying entities with @key, (3) sharing types/fields across subgraphs with @shareable, (4) working with federation directives (@external, @requires, @provides, @override, @inaccessible), (5) troubleshooting composition errors, (6) any task involving federation schema design patterns.

allowed-tools

Bash(rover:*), Read, Write, Edit, Glob, Grep

compatibility

Works with any Federation 2.x compatible subgraph library (Apollo Server, GraphQL Yoga, etc.)

license

MIT

metadata.author

apollographql

metadata.version

1.0.2

extend schema
  @link(url: "https://specs.apollo.dev/federation/v2.12",
        import: ["@key", "@shareable", "@external", "@requires", "@provides"])

type Product @key(fields: "id") {
  id: ID!
  name: String!
  price: Int
}

# Products subgraph
type Product @key(fields: "id") {
  id: ID!
  name: String!
  price: Int
}

# Reviews subgraph
type Product @key(fields: "id") {
  id: ID!
  reviews: [Review!]!
  averageRating: Float
}

type Product @key(fields: "id") {
  id: ID!
  size: Int @external
  weight: Int @external
  shippingEstimate: String @requires(fields: "size weight")
}

type Money @shareable {
  amount: Int!
  currency: String!
}

type Product @key(fields: "id", resolvable: false) {
  id: ID!
}

© apollographql, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files (references) in skills/apollo-federation of apollographql/skills.

• SKILL.md
• references/composition.md
• references/directives.md
• references/schema-patterns.md

Open the folder on GitHubat commit 5f02fcf