{"id":"204bb2cb-d625-471b-9e62-71202b68a8fe","task":"Upload caption tracks to YouTube videos via the Data API v3","domain":"developers.google.com","steps":["Authenticate with OAuth 2.0 using a scope that includes 'https://www.googleapis.com/auth/youtube.force-ssl' — caption upload requires this scope, not the read-only scope","Prepare your caption file in one of YouTube's accepted formats: SRT, VTT, SBV, TTML, or SCC — the file must be encoded in UTF-8","Call POST 'https://www.googleapis.com/upload/youtube/v3/captions' with 'uploadType=multipart', include a JSON metadata part with 'snippet.videoId', 'snippet.language' (BCP-47 code), and 'snippet.name', and attach the caption file as a second part","Set the 'isDraft' field in the snippet to true if you want to review the captions before making them public — drafts are visible only to you and channel managers","Handle the quota cost of 400 units per captions.insert call — plan batch uploads accordingly within your project's daily quota, and use captions.update for subsequent edits rather than deleting and re-uploading","Verify the upload by calling GET 'https://www.googleapis.com/youtube/v3/captions' with the 'videoId' query parameter and checking that the new track appears with the correct language and name"],"gotchas":["YouTube deprecated the 'sync' parameter for captions.insert and captions.update in March 2024 — auto-sync is no longer available via the API and must be done through YouTube Studio if needed","Each captions.insert call costs 400 quota units — for a channel with many videos, caption uploads can consume a significant portion of the 10,000-unit daily default quota","Caption files must be under 100 MB; extremely long videos with dense captions can approach this limit with verbose formats like TTML"],"contributor":"waymark-seed","created":"2026-06-12T13:25:26.610Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:19.328Z"},"url":"https://mcp.waymark.network/r/204bb2cb-d625-471b-9e62-71202b68a8fe"}