# ActiveCampaign Contact Sync

## Objective

Create or update ActiveCampaign contacts and place them in the right lists and automations.

An outbound sync that upserts contacts, applies list membership and custom fields, and enrolls them in automations deliberately.

## Before You Begin

This feature is being added to an application that already exists and already
works. Do not scaffold a new project, and do not assume a blank slate.

Inspect the codebase first and establish:

- The existing application structure and where code of this kind already lives.
- The framework and version in use.
- The existing design system — colours, spacing, typography, and component conventions.
- Existing UI components you can reuse instead of writing new ones.
- The existing database structure, if this feature needs to persist anything.
- The existing authentication and authorization system, if this feature is user-scoped.
- Dependencies already installed, so you don't add a library that duplicates one.
- The existing test setup and conventions.

Only start writing code once you understand the above. If the application
already implements part of this feature, extend it rather than replacing it.

## Implementation Instructions

1. Upsert every contact against one canonical identifier — the normalized email, or a stored provider contact ID once you have one — and never fall back to creating a record when a lookup times out.
2. Treat lists, tags, custom fields, and automation enrollment as four separate mappings with four separate rules. Collapsing them into one 'sync everything' action makes it impossible to change list membership without also re-firing an automation.
3. Enroll a contact in an automation only on the specific app event that warrants it, and record that the enrollment happened. A routine profile update must never re-enroll someone who is already in the sequence or has finished it.
4. If the app already has an outbound sync for another email provider, the connection storage, token refresh, backoff, and delivery-log machinery belong to that shared integration layer — extend it. This brief owns only the ActiveCampaign field, list, and automation mapping.
5. Do not drop rate-limited requests or retry them out of order. Queue per contact so that a create, an update, and a tag change for one person are applied in the sequence they occurred.

## UI and UX Requirements

Match the application's existing design system exactly. Reuse its components,
spacing, and typography. This feature should look like it was always there.

## Responsive Requirements

Works on mobile, tablet, and desktop. Touch targets are large enough to hit on a
phone, and nothing overflows horizontally at 320px.

## Accessibility Requirements

- Fully keyboard navigable.
- Correct semantic elements and ARIA roles.
- Visible focus states.
- Meets WCAG AA contrast.
- Dynamic changes are announced to screen readers.
- Respects prefers-reduced-motion.

## Edge Cases

- Two requests for the same person arriving close together will both fail their lookup and both create a contact. Serialize writes per canonical identifier so the second one finds what the first created.
- Lists, tags, custom fields, and automations behave differently on write: a list is membership, a tag is a marker, a custom field is data, and an enrollment is an action with side effects. Mapping them through one code path guarantees one of them is handled wrongly.
- An automation that restarts on every contact update will send the same welcome sequence repeatedly. Track prior enrollment and treat re-enrollment as an explicit, rare decision rather than the default.
- The provider reports contacts as unsubscribed or bounced, and that state outranks anything the app believes. Store it, stop sending, and show it on the contact record so support can explain why a customer is not receiving mail.
- Rate-limited requests that are retried independently will land out of order, applying a stale profile over a newer one. Preserve per-contact ordering through the retry, and back off on the whole queue rather than the individual call.
- Custom fields can be deleted or have their type changed after the mapping was saved. A write against a missing or mistyped field must pause the mapping with a message naming the field, not fail the whole sync silently.
- Access tokens expire and accounts get disconnected. Hold queued events, mark the connection broken in the app, and resume from the held queue once it is reconnected rather than discarding what accumulated.
- When the provider is unavailable, the app's own signup, purchase, or profile save must still complete. Show the sync as pending on the record instead of failing the user's action.

## Testing

Exercise the feature end to end in the running application. Cover every edge case
above, then run the existing test suite and confirm nothing regressed.

## Acceptance Criteria

- [ ] Concurrent events for one person produce a single contact, never a duplicate.
- [ ] List membership, tags, custom fields, and automation enrollment are configured and applied independently.
- [ ] A profile update never re-enrolls a contact in an automation they have already entered.
- [ ] Unsubscribed and bounced states reported by the provider stop further sends and are visible in the app.
- [ ] Rate limiting causes backoff and retry without reordering events for a contact.
- [ ] A deleted or retyped custom field pauses that mapping with a named, actionable error.
- [ ] The shared integration layer, not this feature, owns credentials, refresh, and delivery logs.
- [ ] The feature matches the existing design system.
- [ ] No existing functionality is broken.

## Adaptation Rules

- Match the existing design system. Do not introduce a new colour palette,
  spacing scale, or component library.
- Reuse existing components and utilities wherever they fit.
- Follow the naming, file layout, and code style already present.
- Do not upgrade, replace, or remove existing dependencies to make this
  feature fit. Adapt the feature to the app, not the app to the feature.
- Do not break existing functionality. If a change is genuinely required in
  existing code, make the smallest one that works and say so.
- If something in these instructions conflicts with how the application is
  built, follow the application and explain the deviation.

## Final Verification

Before you report the work as done:

1. Re-read the acceptance criteria above and check each one against what you
   actually built.
2. Run the application and exercise the feature end to end.
3. Run the existing test suite and confirm you have broken nothing.
4. Check the feature on mobile, tablet, and desktop widths.
5. Check keyboard navigation and focus handling.
6. Summarize what changed: files added, files modified, and anything you
   deliberately did differently because of how this application is built.

If any acceptance criterion is unmet, fix it before reporting completion.