What region does Google ADK use with Gemini?

[mattmcc-attest]

This might not be an ADK question but if I create a basic Agent and use a model like "gemini-2.5-flash" - how do I know what Gemini region the request goes to. This is using my own cloud run deployment

[adk-bot]

Response from ADK Answering Agent (experimental, answer may be inaccurate)

TLDR: The Gemini region is determined by the region you specify when deploying your agent to Cloud Run, or by the GOOGLE_CLOUD_LOCATION environment variable in your .env file.

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When you deploy your agent to Cloud Run using the adk deploy cloud_run command, you can specify the region for your deployment using the --region flag. For example:

adk deploy cloud_run --region=us-central1

This will deploy your agent to the us-central1 region, and any calls made to the Gemini API will also be routed to that region. You can see the documentation for the deploy cloud_run command for more details. [1]

Alternatively, if you are using Vertex AI, you can specify the GOOGLE_CLOUD_LOCATION in your .env file. This is also used to determine the region for your Gemini API calls. [2]

For example:

GOOGLE_CLOUD_PROJECT=<your-project-id>
GOOGLE_CLOUD_LOCATION=us-central1

If you do not specify a region, the ADK will prompt you to select one, or it may use the default region configured in your local gcloud settings. The selected region is then passed as the GOOGLE_CLOUD_LOCATION environment variable to the Docker container during deployment. [3]

It is also worth noting that when you enable Cloud Trace for your agent, the traces will also be sent to the same region. [4]

[1] https://google.github.io/adk-docs/deploy/cloud-run/
[2] https://google.github.io/adk-docs/agents/config/
[3] https://github.com/google/adk-python/blob/main/src/google/adk/cli/cli_deploy.py
[4] https://google.github.io/adk-docs/observability/cloud-trace/