Sample period and Interactions mapping for Gemini free-tier request usage metric

Gemini API Documentation
1

Hello,

Could a Google representative or documentation maintainer please confirm two points:

  1. What is the Sample Period for generativelanguage.googleapis.com/quota/generate_content_free_tier_requests/usage? The Cloud Monitoring catalogue documents visibility latency of up to 150 seconds after sampling, but I cannot find the sampling period itself.
  2. Does traffic sent through the stable-v1 Interactions API (/v1/interactions) increment that exact usage metric and the GenerateRequestsPerDayPerProjectPerModel-FreeTier quota limit?

I am looking for an authoritative definition suitable for designing a safe, one-request synthetic developer test. This is a general documentation question and does not concern project-specific troubleshooting.

If the mapping depends on the model, method or route, where is that documented?

Thank you.