YouTube Conventions

Quota math

API call	Cost
`videos.insert`	1,600 units
`channels.list`	1 unit
Daily budget per project	10,000 units
Uploads per project/day	~6

Health checks at scale: 1,000 accounts × 1 unit × 12 runs/day = 12,000 units. Spread across pool projects, stagger runs, skip recently-active accounts.

Token lifecycle

•User authorizes → Google returns authorization_code
•Exchange code → refresh_token + access_token (60 min)
•Cache access_token in KV (50 min TTL)
•On expiry → use refresh_token + project's client_id/client_secret to get new access_token

Critical: refresh_token is permanently bound to the client_id that issued it. Cannot use Project-A's credentials to refresh Project-B's token.

OAuth gotchas

•Google only returns refresh_token on first auth. Always set prompt=consent&access_type=offline.
•"Unverified app" warning on published-but-unverified projects is expected. Users click "Advanced → Continue".
•channels.list(mine=true) returns the channel selected during OAuth, not all channels.
•Multi-channel accounts need separate OAuth per channel.
•Published (not Testing) mode required — Testing tokens expire in 7 days.

Upload errors

Error	Action
`403 quotaExceeded`	Park. Mark project exhausted.
`403 uploadLimitExceeded`	Park. Mark account limited.
`403 channelSuspended`	Permanent fail. Flag account. Cancel queued tasks.
`403 channelNotFound`	Permanent fail. Auto-delete account.
`403 youtubeSignupRequired`	Permanent fail. Flag account.
`403 forbidden`	Permanent fail. Flag + health check.
`429`	Backoff: 1s → 2s → 4s → … 5 min. Max 10 retries.
`500/503`	Retry 5× with jitter.
`401`	Refresh token, retry once. If fails → flag account.
`400`	Permanent fail. Don't retry.

Resumable uploads

YouTube's resumable upload protocol for videos >5MB:

•POST to initiate → get upload_url
•PUT chunks (256KB minimum, except final)
•On interruption → PUT with Content-Range: bytes */* to get resume offset
•Must complete within 24h of initiation

Keep chunks small enough to finish within Workers' 30s CPU limit.