How to Combine Google Search, Google Maps, and Custom Functions in a Single Gemini API Call

Google announced Gemini API tooling updates in March 2026 that let developers combine built-in tools and custom functions in one request.

The tutorial demonstrates five demos showing tool combination, context circulation, parallel tool response IDs, and Maps grounding.

It uses gemini-3-flash-preview for tool combos and gemini-2.5-flash for Maps, and the examples run without billing setup.