You are helping me build the following AI agent workflow.

## Goal
Personalized Hotel Reward Emails for High-Spenders: After a hotel guest checks out, the agent calculates their total amenity spend and emails a personalized free service offer if they spent...

## Specification
- What it does: You receive a personalized free service offer via email after your checkout if you spent at least $50 on hotel amenities. The system automatically calculates your total spend, identifies your VIP status, and sends a branded reward for unused services based on your specific usage.
- Trigger: Triggered by an event (Event · on new checkout)
- Autonomy: Fully hands-off
- Expected setup effort: about an afternoon
- Tools/services involved:
  - Salesforce: Monitor checkouts and fetch guest spend data
  - Code: Calculate total amenity spend and filter VIP guests
  - Google Vertex Chat Model: Generate personalized promo text using AI
  - Structured Output Parser: Clean and parse AI output into JSON
  - Brevo: Send personalized HTML reward emails

## Known pitfalls, handle each one explicitly in your implementation
1. Brevo authentication tokens expire periodically, so integrate automatic token refresh logic to prevent silent delivery failures.
2. High spend thresholds might exclude valuable mid-tier guests, so review the $50 cutoff monthly and adjust based on conversion metrics.

## Reference implementation
https://n8n.io/workflows/5936 (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/personalized-hotel-reward-emails-for-high-spenders/ via usecasesforagents.com