Vimeo OTT will build your SDK package once you set everything up.
https://vimeo.com/ott/home
Another option in the same vein is Zype
https://zype.com
Both are content record management solutions and cost about $1-$2k / mo for streaming channel deployments.
Fastest and cheapest way to deploy a Roku Channel is using Vimeo Pro and a json feed file, and then giving the unique code of the channel as part of the receipt of payment. That doesn't scale, but it gets you started for about $200/yr.
Serve your videos from Vimeo Pro as HLS links, and serve the thumbnails and feed file from any website.