Capstone Part 4: Resilience & Reporting

Nexus-One is almost complete. In this lesson, we add the "Weekly Digest" report and setup our "Global Safety Net."

1. The Weekly Digest (Review Module 7)

Add a Schedule node (set to Friday at 4 PM). Add a Google Sheets node.

• Operation: Read all rows from Sales-Data. Add an Aggregate node (Module 4).
• Sum: Amount.
• Count: Rows. Add a Gmail node.
• Message: Nexus-One Weekly Update: We processed {{ $json.count }} sales for a total of {{ $json.sum }} this week.

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2. Global Error Handler (Review Module 9)

Create a New Workflow.

1. Add an Error Trigger.
2. Add a Telegram or Slack node.

• Message: ⚠️ Nexus-One ALERT: Workflow '{{ $json.workflow.name }}' failed at '{{ $json.timestamp }}'. Error: {{ $json.execution.error.message }}.

In your Lead Engine and AI Support workflows:

• Go to Workflow Settings -> Error Workflow -> Select your new handler.

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3. The "Self-Cleaning" Log (Review Module 11)

Set your Production n8n environment variable: EXECUTIONS_DATA_MAX_AGE = 168 (7 days).

• This ensures that Nexus-One doesn't fill up your server's hard drive over time.

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Exercise: The Reliability Drill

1. Intentionally break your "Lead Engine" by disconnecting your internet (or using a fake API key).
2. Verify that your Global Error Handler sends you a notification.
3. Does the Weekly Digest correctly aggregate multiple rows of data into one sum?
4. Why is it important to have the "Weekly Digest" on a separate workflow from the "Lead Engine"? (Review Module 5 - Modular Design).
5. Research: How would you add a chart/graph image to your Weekly Digest email?

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Summary

You have finished the implementation of Nexus-One. You have a system that sells, thinks, reports, and—most importantly—self-monitors. You have moved from a "Builder" to an "Operator."

Next Lesson: Part 5: Final Review & Conclusion.