Agent Skills: Skill: frontend/data-fetching-integration

Skill: frontend/data-fetching-integration

Purpose

Connect UI to an API/data source using the repo’s data tooling, ensuring:

• typed inputs/outputs
• correct UI state handling
• explicit caching and invalidation behavior

Inputs

• Data source definition:
  • endpoint contract (method/path/request/response) OR
  • client function signature OR
  • data description (if contract not formalized yet)
• UI entry point(s) that need the data
• Expected behavior:
  • read vs write
  • polling or realtime needs
  • optimistic updates allowed (yes/no)
• Repo profile (preferred): <repo>/REPO_PROFILE.json

Outputs

• Data call wired via repo tooling (React Query/SWR/custom)
• A hook / loader / data module consistent with repo patterns
• UI state coverage:
  • loading
  • error
  • empty
  • success
• Explicit cache key strategy and invalidation/refetch rules (code comments or helper constants)

Non-goals

• Changing backend behavior or contracts
• Adding business rules client-side beyond presentation and basic form validation
• Building a new data layer abstraction unless explicitly requested

Workflow

1. Identify the repo’s data fetching pattern (prefer REPO_PROFILE.json).
2. Implement the data call using existing client conventions.
3. Define a stable cache key derived from request inputs.
4. Add invalidation rules:
   • mutations invalidate queries that depend on changed data
   • avoid global invalidation unless required
5. Implement UI states:
   • loading: skeleton/spinner (repo standard)
   • error: recoverable messaging + retry path if appropriate
   • empty: explicit “no data” state
   • success: render
6. Run required validations (typecheck/lint/tests per profile).

Checks

• Typecheck passes (if configured)
• UI handles loading/error/empty/success states deterministically
• Cache key is stable and unique
• Invalidation/refetch behavior is explicit
• No silent swallowing of errors

Failure modes

• Data tooling unclear → ask which is used (React Query/SWR/custom) and default caching expectations.
• Stale cache → fix keys and invalidation rules; avoid ad-hoc refetch loops.
• Race conditions → add latest-only guards, cancellation, or stable request identity.
• Contract ambiguity → recommend api/contract-update or shared/schema-types before hard wiring.

Telemetry

Log:

• skill: frontend/data-fetching-integration
• data_tooling: react-query | swr | custom | unknown
• cache_keys_added_or_changed
• files_touched
• outcome: success | partial | blocked