The citation_check.py script costs about $1-3 per run on Anthropic API (5 queries × 2 runs × ~5 web_search uses each). Cheap enough to run monthly without thinking.
The GA4 "AI-referrer cut" is the single number I find most useful from this stack. It's the only direct measure of whether AI citations convert to actual visits. Most clients have zero AI referrals at baseline, which gives you a clean trajectory to work against.
gsc_pull and ga4_pull both use Application Default Credentials (gcloud auth application-default login). No service account keys on disk. Works even when your Workspace org blocks key creation.
Tested with Googlebot UA only for the prereqs sweep. Curious if anyone has seen GPTBot/ClaudeBot/PerplexityBot diverge on the same site (haven't tested per-bot UA in code yet, would be a good v0.2 contribution).
Happy to answer architecture, methodology, or specific use case questions.