Sketch

Sketch is an image drawing and editing app for smart phones made by Sony. The online parts of Sketch were discontinued on 2019-09-30 (or more precisely a few days later, sometime between 3 and 6 October).
== User counts ==
The corporate user account, https://sketch.sonymobile.com/u/sonysketch, which new accounts automatically follow, shows "1795890 FOLLOWERS" as of 2019-05-08 01:40 UTC "2073078 FOLLOWERS" as of 2019-07-08 20:51 UTC.
== Browser URLs ==
Browsing pages:
* https://sketch.sonymobile.com/explore/featured
* https://sketch.sonymobile.com/explore/popular
* https://sketch.sonymobile.com/explore/trending
* https://sketch.sonymobile.com/explore/world
* ( On mobile, there is an additional page called "Newcomer" )
By tag:
* Tag page: https://sketch.sonymobile.com/tag/cat
By user:
* Hash based: https://sketch.sonymobile.com/profile/23135ca9-16a7-424c-a376-93004cd05782/username/aleyandra-loprogy
* Hash only: https://sketch.sonymobile.com/profile/23135ca9-16a7-424c-a376-93004cd05782
* @ based: https://sketch.sonymobile.com/u/Bjnni
Sketch pages:
* Sketch page (linked from user pages): https://sketch.sonymobile.com/feed/a72ed347-7606-4a99-8b3e-934fb809d5a1
* Sketch page from tag page (once per tag): https://sketch.sonymobile.com/tag/GoodbyeSketch/sketch/a72ed347-7606-4a99-8b3e-934fb809d5a1
* Sketch page from explore page (up to 4-5 versions): 
https://sketch.sonymobile.com/explore/featured/sketch/a72ed347-7606-4a99-8b3e-934fb809d5a1
== Images ==
* A sketch's image file: https://storage.sketch.sonymobile.com/feed/6362d4d6-b91a-4603-8062-d59f3629e11d/image Redirects to Amazon S3 https://sketch-cloud-storage.s3.amazonaws.com/ed17f5ee-2960-4f71-8cf2-bbe36dfe96f4/312a714f-fe8b-4e5d-bf94-38bedc701e92_p?AWSAccessKeyId=AKIAIVK24H6RLSWCC7OA&Signature=YBVoxPocGqLxhPaoj50gVK8rqgo%3D&Expires=1557278433
* Avatar https://sketch-cloud-storage.s3.amazonaws.com/public_images/46a427b2-3375-4eeb-a046-8e545a652ff7_s
* Thumbnail 
https://sketch-cloud-storage.s3.amazonaws.com/23135ca9-16a7-424c-a376-93004cd05782/40517d90-48a0-4be8-a3e1-f049437d5d62_s?AWSAccessKeyId=AKIAIVK24H6RLSWCC7OA&Signature=Mz1nTU887qV2COZNWsIpRSaC4fw%3D&Expires=1556691065
== API ==
The following endpoints can be used to list sketches, and powers the explore view:
* https://sketch.sonymobile.com/api/1/feed/newcomer/list/default/
* https://sketch.sonymobile.com/api/1/feed/featured/list/default/
* https://sketch.sonymobile.com/api/1/feed/trending/list/default/
* https://sketch.sonymobile.com/api/1/feed/popular/list/default/
* https://sketch.sonymobile.com/api/1/feed/global/list/default/
The last one seems to list all (23 million) available sketches.
Example usage:
* https://sketch.sonymobile.com/api/1/feed/global/list/default/api%2Ffeeds%2Fglobal%3Fn%3D180817470%26l%3D150 (Decodes to api/feeds/global?n=180817470&l=150)
Other APIs
* User search (limited to 50 results, no pagination): https://sketch.sonymobile.com/api/1/search/artist/<term>
* Tag search: https://sketch.sonymobile.com/api/1/search/tag/<term>
* Tags: https://sketch.sonymobile.com/api/1/feed/hashtag/cat/list/
* Single sketch: https://sketch.sonymobile.com/api/1/sharedsketch/be39ea26-ebf6-4dfb-84d5-d9e122d3191e
* Artist (can include multiple UUIDs, separated by commas): https://sketch.sonymobile.com/api/1/artist/d51e31f9-6aa1-474b-9e0e-3357e9bc2b9c
* Artist’s pictures: https://sketch.sonymobile.com/api/1/feed/artist/92b9afe4-3d4c-48d0-839d-a9fedba8a38a
* Comments: https://sketch.sonymobile.com/api/1/comments/sketch/92b9afe4-3d4c-48d0-839d-a9fedba8a38a/be39ea26-ebf6-4dfb-84d5-d9e122d3191e
Additional APIs are needed for the mobile app to function but have not yet been located.
* Who's following whom
* Related tags to currently viewed tag
== AWS S3 Expiration issue ==
Almost all the images live in AWS S3. Many of these URI tokens expire 1 hour after being generated. A link can be checked whether it's expired because the Expired parameter is a timestamp after which it will not longer be valid. Where this is particularly problematic is the thumbnail URLs. Any webpage that contains a thumbnail image, those images need to be grabbed in the next hour or will be missing and can not be repaired later.
== Saving with the internet archive ==
Saving urls with https://web.archive.org/save/ actually works great, even though it looks like it fails.
The page will always show "404 Not Found", such as this random example.
But the page html contains: \"imageUrl\":\"https:\u002F\u002Fsketch-cloud-storage.s3.amazonaws.com\u002Fac16b85e-f285-44f3-ae2d-4c3ccdc1f413\u002F2ad6cf73-41f7-4048-aa2f-2eaca80b1ebc_s?AWSAccessKeyId...
And that link works, at least as a prefix search: https://web.archive.org/web/*/https://sketch-cloud-storage.s3.amazonaws.com/ac16b85e-f285-44f3-ae2d-4c3ccdc1f413/2ad6cf73-41f7-4048-aa2f-2eaca80b1ebc*
In fact, it gets both png ang jpeg formats!
We saved a random sample of about 50,000 pages (in addition to whatever the real code has saved).
There might be 18 million pages (the /feed/global/list/ urls seemed to run from about 180817470 to about 199228198)? If true, we saved 1 in 300 images.
== References ==