The Vendors page lets you view all the game's vendors and what they have available.
Only Show Uncollected Items
By enabling this option, the vendors view will be narrowed down to show only items which are collectible/unlockable (in Collections, for example) that you haven't already unlocked.
What shows up on the vendor page depends on which of your characters you have selected, and some other conditions.
- Spider may not appear to some characters, typically because they have not completed the Forsaken campaign. If he is missing but you usually see him, you probably need to select another one of your characters on the Vendors page.
- Petra doesn't show up in the API unless the character is logged in and standing in the Dreaming City.
- Visage of Calus stopped showing up in the API several seasons ago.