What Breaks When Apps Script Projects Sprawl

Conclusion first: Once Apps Script projects exceed 15, owner turnover, duplicate triggers and missing manifest scopes cause immediate execution failures. A single registry sheet must become the source of truth for names, owners, triggers, scopes and deployment mappings.

1. Six Destruction Points Created by Project Sprawl

Duplicate names, owner departure, trigger collisions, omitted scopes, version drift and absent documentation occur simultaneously.

2. Registry Schema (Single Source of Truth)

{
  "projectId": "1abc2def3ghi",
  "name": "invoice-sync-v2",
  "owner": "[email protected]",
  "triggers": [{"type":"time","function":"runSync","everyMinutes":5}],
  "scopes": ["https://www.googleapis.com/auth/spreadsheets"],
  "currentVersion": 12,
  "deployments": [{"version":12,"url":"https://script.google.com/..."}],
  "folderPath": "finance/invoice",
  "lastAudit": "2024-10-01"
}

3. Naming & Ownership Rules

Project ID is the permanent key; display name is functional + environment only. Owner must be a group or dedicated service account.

4. Trigger Inventory Checklist

Item	Verification	Failure Impact
triggerId	ScriptApp.getProjectTriggers()	duplicate runs / infinite loop
ownerEmail	registry lookup	stops after departure
functionName	manifest entry	404 errors

5. Manifest Scopes & Version Mapping

6. Clasp Folder Structure and Operational Failure Modes

Failing to align clasp.json rootDir with the registry folderPath causes deployment URLs to change on every push. Omitting .claspignore leaks sensitive files.

7. When NOT to Use This Approach

Skip the registry overhead for five or fewer projects or when every script is bound to a single document. Introduce it only beyond that threshold.

Final review criteria

The useful question is not how many features the automation has. It is whether the workflow can be understood, recovered, and safely rerun after something goes wrong.

• Raw input is separated from the human-facing working view.
• Each run records success, failure, processed count, and error message.
• Replaying the same input does not create duplicate results.
• Permission changes, quota errors, and external API failures are visible later.

For low-risk internal tasks, that may be enough. For customer replies, booking confirmation, inventory updates, payments, or legal records, the threshold is higher: compare Apps Script against a dedicated SaaS or a small server-backed system before relying on it.