Implement GraphQL

Apply the execution contract before this procedure.

Use this skill when designing, implementing, or reviewing GraphQL APIs in a Rails application with the graphql-ruby gem.

Core Process

DO NOT proceed to step 3 before step 1 is written and failing.

1. SPEC: Write failing spec (happy path + auth + validation error case) — see TESTING.md. Use AppSchema.execute in spec/graphql/. Never use HTTP controller dispatch for GraphQL specs.

2. TYPE: Define arguments and return types. Use connection_type for pagination shapes. Do not leak internal model names.

3. IMPLEMENT: Create resolver/mutation class delegating to a service object. Use dedicated classes instead of inline field blocks.