YouTube data-access constraints

One-line summary: Watch history is closed in the Data API; candidate search is capped at 100 search.list calls/day; known-channel uploads are 1-unit playlistItems.list; Developer Policies bar a substitute YouTube browse; google-takeout is a delayed archive.

The insight

The binding constraint on a user-owned rec loop over YouTube is access and policy, not which graph database stores the interests. Public metadata is cheap; history and discovery search are not. From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs.

Evidence

• From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs: playlistItems.list documents forbidden (403) watchHistoryNotAccessible: “Watch history data cannot be retrieved through the API.”
• From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs: Default allocation is “100 search.list calls, 100 videos.insert calls, and 10,000 units per day combined for all other endpoints.”
• From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs: search.list — “100 calls per day, 1 unit per call; each extra results page is another call.”
• From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs: API Clients “must not … use YouTube API Services to create, offer, or act as a substitute for, or substantially similar service to, any YouTube Applications.”
• From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs: Takeout archives expire in about 7 days; time-range export is not supported.
• From 2026-08-21-academic-research-user-owned-interest-graphs-vs-platform-recs: Efstratiou (IMC 2025) — YouTube Data API Search “returns highly variable results between queries”; representative historical video samples are “nearly impossible,” especially off-peak.
• From 2026-08-21-academic-research-user-owned-interest-graphs-vs-platform-recs: Academic methods papers discuss APIs vs data-donation vs tracking (Ohme et al. 2023) and higher willingness to donate YouTube data than Facebook/Instagram/Google (Pfiffner et al. 2023). They do not restate watchHistoryNotAccessible or measure Takeout delay.
• From 2026-08-21-autoresearch-best-architecture-for-a-rec-system-web-app: Official serving path for a known channel is channels.list → contentDetails.relatedPlaylists.uploads → playlistItems.list (maxResults 50, 1 unit/page) — not search.list.
• From 2026-08-21-autoresearch-best-architecture-for-a-rec-system-web-app: Policies re-fetched: API Clients “must not recreate the browse experience from any YouTube Application without adding significant independent value to that flow.”
• From 2026-08-21-autoresearch-best-architecture-for-a-rec-system-web-app: Private user/channel data needs OAuth; public metadata can use an API key — a separate auth plane from graph ownership (local-first-software, solid-project).

Contradictions / tensions

• A tool that filters the user’s own Takeout archive against a graph they drew is a different fact pattern than a live YouTube-like homepage. No fetched YouTube ruling on that case.

Related

• youtube-platform
• google-takeout
• youtube-recommendation-system
• user-owned-interest-graph
• data-donation
• multi-stage-rec-serving
• user-owned-graph-to-quota-aware-youtube-serving