7. GraphQL Resolvers

[mrserverless]

• 7.1 Generate GraphQL code (go generate ./graphql)
• 7.2 Implement graphql/resolver.go
  • Resolver struct with domain service fields
  • AccountService, TransactionService, BalanceService, ConsentService
  • NewResolver(services...) constructor
• 7.3 Implement Query resolvers
  • Query.Account(ctx, id) - delegate to AccountService.RetrieveCurrentAccount
  • Query.Balance(ctx, accountID) - delegate to BalanceService.RetrieveAccountBalance
  • Query.Transactions(ctx, accountID, input) - delegate to TransactionService.RetrievePaymentTransactionHistory
  • Query.Consent(ctx, id) - delegate to ConsentService.RetrieveConsent
• 7.4 Implement error handling
  • Map domain errors to GraphQL errors
  • Not found → user-facing error message
  • Internal errors → generic error message
• 7.5 Implement input validation
  • Validate account IDs (not empty)
  • Validate date ranges (start before end)
  • Validate pagination (limit > 0)

Source: openspec/changes/bootstrap-mvp-foundation/tasks.md