You are helping me build the following AI agent workflow.

## Goal
Customer Feedback Processing: Receives customer feedback via webhook, analyzes sentiment with AI, generates a branded PDF report, emails it to the user.

## Specification
- What it does: You automatically receive AI-analyzed sentiment reports on customer feedback directly in your inbox. This workflow extracts key insights from incoming submissions, generates branded PDF summaries, logs the data for tracking, and alerts your team via Slack.
- Trigger: Triggered by an event (Event · on webhook submission)
- Autonomy: Fully hands-off
- Expected setup effort: about an afternoon
- Tools/services involved:
  - OpenAI: Sentiment analysis and insight extraction
  - Gmail: Sending personalized thank-you emails with PDF attachments
  - Google Sheets: Logging feedback data for analytics and audit trails
  - Slack: Notifying team channels with real-time summaries

## Known pitfalls, handle each one explicitly in your implementation
1. OpenAI API costs can escalate quickly with high volume, so implement caching for identical feedback inputs.
2. Email delivery may fail if Gmail authentication tokens expire, so add a refresh token mechanism to the workflow.
3. PDF generation libraries often struggle with complex CSS, so keep the HTML template simple and test rendering early.

## Reference implementation
https://n8n.io/workflows/9489 (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/automate-customer-feedback-processing/ via usecasesforagents.com