Two routes, different scales
- Apps Script: runs inside Workspace, no hosting, ideal for focused automations
- Workspace APIs: external service, needed for anything substantial or shared
Starting with Apps Script for a first automation is often the right call. It proves the value for almost nothing.
What works well
- Shared inbox triage with labels and routing in Gmail
- Drive document retrieval for an internal assistant
- Sheets validation — flagging rows that break your rules
- Form submissions extracted, enriched and routed
- Doc assembly from templates and structured data
Sheets integration is particularly valuable because so many businesses genuinely run on a shared spreadsheet, and the API makes it a real system of record rather than a file.
Permission model
OAuth scopes should be as narrow as the task allows. Domain-wide delegation is powerful and worth avoiding unless a background process genuinely requires it.
Verification requirements apply to some scopes for external apps; internal-only apps within your domain avoid most of that.
Where Apps Script runs out
| Limit | Consequence |
|---|---|
| Execution time quota | Long jobs need chunking |
| Daily quotas | High volume needs an external service |
| Limited dependency management | Complex logic gets awkward |
| Version control | Needs deliberate setup |
Below those limits it is excellent. Above them, move to a proper service rather than fighting the platform.
A sensible progression
Prove the automation in Apps Script, measure the value, then rebuild as a service if volume or complexity demands it.
That path costs very little and it avoids building infrastructure for something that turns out not to be used.