This seems really cute but this probably the biggest patch I ever dropped. Most of the feedback I got want this or something like this, and been working and developing the feature for a long time until it satisfies my vision on the feature. Even after rolling the update to the public I'm still not quite happy about it, there still works to do but for now, that will work.
Legitimacy of purchased giftable items is not that reliable and can be faked. That is why buyers having hard time to choose where to buy or whom. Enter the screen shots verification, which really help a bit to validate and build trust to a seller, but still can be faked. That's why the transaction history helps form a reputation. Others might say commending or review system help this and yes, it can be but we go back to the problem of checking the legitimacy of the review and yes! it can be faked too and checking the profiles of the reviewers will not be easy. Basically we need a trusted source of data, Steam Inventory itself.
Public Steam inventory is pretty reliable. We check if the item listed there then we are good, simple, right? Not so fast! Although Steam inventory provide API for data source is really helpful but its not so stable and hard to find documentation, even steam client are getting errors before, so we can't really rely on this alone. Thanks to @necrolytus creator of steaminventory.org doing what a stable steam inventory API should be, its not perfect but we can rely on it.
We already have a reliable data source, now we need to provide ease of consuming data for the buyers. Worked on parsing the data and transforming it into a simple form. added verification level to cater the states of an item when gifted, from wrapped gift to un-bundled. Detecting giftable un-bundled sets. Turns out I don't know how to show this to a user-interface that will still support existing items and not drastically change the design that will consume more time. After several traveling in space and time I decide to show them in icons with a popover containing details of the verification that they can check them selves if they want to.
The icon statuses is so minimal on the surface but provides information at glance and able to geek out details if you wanted to. This helps them form a decision when they checking out a listing of an item, or even build reputation on seller's profile at glance. Also its so satisfying when you see green checks on your profile and some golden-double-checks on history. This system can provide a source of legitimate purchased items of giftable goods that we can use as metric to verify or rate a seller.
"But how about private inventories?" That is for another time but initial thoughts about this is to just send a link confirmation to buyer or show it on their dashboards. For now I'm not really sure yet. Since this is the last promised feature I will ever add to this project I've still meaning to add complete it until handling private inventories.
At the time of this writing the voting for next feature is still going but Commend & Report is winning but let's see what wins and if we reach the next secret goal to implement the next feature. out!