Expertise·API Development·v1.0.2

Apollo Federation

Guide for authoring Apollo Federation subgraph schemas: entities with @key, @shareable, federation directives and composition error…

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Buy it · $79 Read it before you buy $79 Written by apollographql · unverified publisher
Context cost
9.7k tokensestimated from the bundle, loaded when it triggers
Bundle
4 files · 38.8 kBtext throughout, nothing executable
Licence
MITpaid listing
Last change
v1.0.2
Servers it uses
Noneruns standalone

What it does

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.

Installed, it changes the agent in these ways.

What this skill changes about the agent is not written down here yet. The listing was collected from its source, and the description is in its own SKILL.md.

Expertise

Domain judgement the base model does not have.

graphqlfederationsubgraphschema
Filed under

API Development

The skill itself

This is the whole product. A skill is instructions the model reads, so there is nothing behind the listing you cannot see first — the front matter loads with every session, and the body below it loads when the skill triggers.

SKILL.md4.0 kB · 128 lines
--- 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. license: MIT compatibility: Works with any Federation 2.x compatible subgraph library (Apollo Server, GraphQL Yoga, etc.) metadata: author: apollographql version: "1.0.2" allowed-tools: Bash(rover:*) Read Write Edit Glob Grep ---
19# Apollo Federation Schema Authoring
20
21Apollo Federation enables composing multiple GraphQL APIs (subgraphs) into a unified supergraph.
22
23## Federation 2 Schema Setup
24
25Every Federation 2 subgraph must opt-in via @link:
26
27```graphql
28extend schema
29 @link(url: "https://specs.apollo.dev/federation/v2.12",
30 import: ["@key", "@shareable", "@external", "@requires", "@provides"])
31```
32
33Import only the directives your subgraph uses. The version shown (v2.12) is
34illustrative — check the [Federation changelog](https://www.apollographql.com/docs/graphos/schema-design/federated-schemas/reference/versions)
35for currently supported versions before copying it verbatim.
36
37> A subgraph's @link version is a floor, not the composition version — see
38> [Federation versions](references/composition.md#federation-versions-floor-vs-composition)
39> for the full explanation.
40
41## Core Directives Quick Reference
42
43| Directive | Purpose | Example |
44|-----------|---------|---------|
45| @key | Define entity with unique key | type Product @key(fields: "id") |
46| @shareable | Allow multiple subgraphs to resolve field | type Position @shareable { x: Int! } |
47| @external | Reference field from another subgraph | weight: Int @external |
48| @requires | Computed field depending on external fields | shippingCost: Int @requires(fields: "weight") |
49| @provides | Conditionally resolve external field | @provides(fields: "name") |
50| @override | Migrate field to this subgraph | @override(from: "Products") |
51| @inaccessible | Hide from API schema | internalId: ID! @inaccessible |
52| @interfaceObject | Add fields to entity interface | type Media @interfaceObject |
53
54## Reference Files
55
56Detailed documentation for specific topics:
57
58- [Directives](references/directives.md) - All federation directives with syntax, examples, and rules
59- [Schema Patterns](references/schema-patterns.md) - Multi-subgraph patterns and recipes
60- [Composition](references/composition.md) - Composition rules, error codes, and debugging
61
62## Key Patterns
63
64### Entity Definition
65
66```graphql
67type Product @key(fields: "id") {
68 id: ID!
69 name: String!
70 price: Int
71}
72```
73
74### Entity Contributions Across Subgraphs
75
76```graphql
77# Products subgraph
78type Product @key(fields: "id") {
79 id: ID!
80 name: String!
81 price: Int
82}
83
84# Reviews subgraph
85type Product @key(fields: "id") {
86 id: ID!
87 reviews: [Review!]!
88 averageRating: Float
89}
90```
91
92### Computed Fields with @requires
93
94```graphql
95type Product @key(fields: "id") {
96 id: ID!
97 size: Int @external
98 weight: Int @external
99 shippingEstimate: String @requires(fields: "size weight")
100}
101```
102
103### Value Types with @shareable
104
105```graphql
106type Money @shareable {
107 amount: Int!
108 currency: String!
109}
110```
111
112### Entity Stub (Reference Without Contributing)
113
114```graphql
115type Product @key(fields: "id", resolvable: false) {
116 id: ID!
117}
118```
119
120## Ground Rules
121
122- ALWAYS use Federation 2.x syntax with @link directive
123- ALWAYS import only the directives your subgraph uses
124- NEVER use @shareable without ensuring all subgraphs return identical values for that field
125- PREFER @key with single ID field for simple entity identification
126- USE rover supergraph compose to validate composition locally
127- USE rover subgraph check to validate against production supergraph
128
In the file
SKILL.md519 words
Files4
LicenceMIT
Why you can read it

Nothing in a skill executes. The client loads the text and the model follows it, so a skill can be audited the way a runbook is — by reading it.

What it costs in context

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≈180
always loaded
The name and description, so the model knows the skill exists and when to reach for it.
9,520
on trigger
The instruction body and 3 supporting files, read only when the skill fires.
4.9%
of a 200k window
Ten skills this size would take about 49% of the window before you open a file.
050k100k150k200k context window

9.7k tokens, estimated from the bundle at four bytes to the token, held for the rest of the session once it triggers. Heavy. Teams tend to install this one per project rather than globally, and load it only when the job comes up.

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The procedure it runs

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Prose, not code

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Servers it uses

None. This skill calls no MCP servers at all.

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What it asks for
Writes filesyes
Network accessno

Read from the allowed-tools line of this skill’s own SKILL.md. A skill grants no permissions of its own — it can only ask for tools your client already has.

What it will not do

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What this skill is not for has not been published here. Nothing is implied by that: it is a section the author has not filled in.

What is in the bundle

4 files, 38.8 kB on disk. A bundle is text throughout: the instructions the model reads, plus the templates it fills in.

  • SKILL.md4.0 kB
  • references/composition.md7.9 kB
  • references/directives.md19.7 kB
  • references/schema-patterns.md7.2 kB
What is not in it

No dependencies and nothing executable: a skill is text the agent reads, so the bundle is 4 files you can review in full before installing. The MIT licence covers the templates and examples as well as the instructions.

Install

Installing copies the bundle into your project. Nothing runs at install time — the files sit on disk until the model reads them.

$79 once
Apollo Federation · MIT · apollographql
one-time
Price$79 once
LicenceMIT — the author’s, unchanged by this purchase
Paid throughStripe, once, on the card you add at the checkout
Keeps workingfor good — the files are yours once they are on disk
Updatesevery release of 1.x through this account

You can read the whole bundle before paying — the SKILL.md above is the product, not a preview of it. What the money buys is the delivery: the folder packaged and handed to your machine by key, every update its author ships, and our support if it does not do what this listing says. The terms of use are MIT, set by the author and unchanged by buying it here.

Payment runs through Stripe, on a page like this one rather than a redirect. Once there is an account it joins the same mcprush invoice as everything else you run, so there is never a second card to enter.

Which clients pick it up on their own

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Claude Code.claude/skills/
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ChatGPT
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Codex CLI.agents/skills/
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This release
Version1.0.2
Publishedno release date on file
Price$79
Referenceapollographql/apollo-federation

Versions

v1.0.2 is what is on the shelf; no release here carries a date. Instructions change more often than APIs do — a skill can be rewritten entirely without anything it depends on moving.

v1.0.2
  • No earlier releases have been published to the marketplace.
Pinning

Put apollographql/apollo-federation@1.0.2 in the install command to hold this exact version. Without the suffix you get whatever is current the day you install, and nothing moves under you afterwards.

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