YouTube Data API search quota is a separate per-method cap from the overall unit budget

The YouTube Data API v3 has two independent quota systems that trip up pipeline builders:

1. Overall unit budget: 10,000 units/day (search costs 100 units, channels/videos.list cost 1 unit each)
2. Per-method caps: search.list has a separate "Search Queries per day" limit, defaulting to 100 queries/day

You can burn through the per-method search cap (100 searches × 100 units = 10,000 units) while the overall budget shows only ~1% used, because channel/video lookups are 1 unit each and don't count toward the search cap.

The per-method cap is editable in Google Cloud Console → APIs & Services → YouTube Data API v3 → Quotas, but increasing it beyond 100 requires a compliance audit (privacy policy, ToS updates, screenshots). Setting it to 500 is a sweet spot — you'll hit the overall 10k unit ceiling before exhausting 500 searches.

For batch pipelines: cache search results aggressively (the video/channel IDs don't change), and use channels.list / videos.list for metadata (1 unit each, up to 50 IDs per call) instead of re-searching.