Google Data Studio is an application for creating data dashboards. It uses connectors to pull data from outside sources and visualizations (also referred to as “charts” in the UI) to display the data. Developers can create custom connectors to bring in data from sources not supported by the default connectors and custom visualizations to visualize data in ways not supported by the default visualizations.

Reference

Usage

Custom Connectors and Data Sources

Local Development

Problems

Custom Connectors

Reference

Limitations

These are the current limitations (as of 2021-07-26) limitations for Google Apps Script which is the service that runs Data Studio community connector scripts. I have bolded features whose limitations I have run up against.

FeatureConsumer (e.g., gmail.com) and G Suite free edition (legacy)Google Workspace accounts
Script runtime6 min / execution6 min / execution
Custom function runtime30 sec / execution30 sec / execution
Simultaneous executions3030
Email attachments250 / msg250 / msg
Email body size200 KB / msg400 KB / msg
Email recipients per message50 / msg50 / msg
Email total attachments size25 MB / msg25 MB / msg
Properties value size9 KB / val9 KB / val
Properties total storage500 KB / property store500 KB / property store
Triggers20 / user / script20 / user / script
URL Fetch response size50 MB / call50 MB / call
URL Fetch headers100 / call100 / call
URL Fetch header size8 KB / call8 KB / call
URL Fetch POST size50 MB / call50 MB / call
URL Fetch URL length2 KB / call2 KB / call

Source: Google Apps Script quotes and limitations

Workarounds