You are helping me build the following AI agent workflow.

## Goal
Accounting Deadline Alerts: Daily checks of Companies House filing deadlines send colour-coded urgency emails to your team with a clickable confirmation audit trail.

## Specification
- What it does: Receive daily, colour-coded email alerts about your accounting clients' UK Companies House filing deadlines so you can track urgency instantly. You get a clickable confirmation link in each message that automatically updates your Google Sheet to maintain a clear audit trail of who has acknowledged every deadline.
- Trigger: On a schedule (Scheduled · daily 5 PM)
- Autonomy: You stay in control
- Expected setup effort: under an hour
- Tools/services involved:
  - Google Sheets: Client data storage and audit trail
  - HTTP Request: Querying Companies House API for deadlines
  - Gmail: Sending colour-coded email alerts
  - Code: Processing logic and webhook handling

## Known pitfalls, handle each one explicitly in your implementation
1. Gmail quotas may be exceeded if many deadlines fall on the same day, batch emails or stagger sends by minute intervals.
2. API responses might return null values for optional fields, add default fallback strings so the sheet does not break.

## Reference implementation
https://n8n.io/workflows/10707 (workflow template)
Fetch and inspect this before building. If it matches my stack, adapt it;
if not, rebuild the pattern with my tools.

## Process requirements
1. Before building: ask me which of the listed tools I actually use and
   what my platform is (n8n / Make / code / other). Do not assume.
2. Adapt the pattern to my answers; do not force the reference stack.
3. Address every pitfall above; tell me how you handled each.
4. Provide a test plan I can run before letting this touch real data.
5. Ask before any step that sends messages, modifies data, or spends money.

Source: https://usecasesforagents.com/use-case/accounting-deadline-alerts/ via usecasesforagents.com