As part of its 10-level characters class compendium, Giffyglyph focused the ranger on using ''scaps'' he gather on a long rest to make traps. You may want to use those mechanics to create a rogue archetype:
Giffyglyph's Class Compendium | The Ranger
At 3rd, gain 2 traps, and 5 ''scraps''; the numbers increase at level X, Y and Z (you may want to reffluf them as more arcane if you want)
Also at 3rd add a ''animated tools'' with the same action economy as the new UA pets (steel defender, primal beast, wildfire thingy) that can use its action to cast ''mending'' and maybe alarm/
knock/arcane lock, Int mod/Day.
at 9th level, gain the the improved tool function you created for that assassin's class we worked on (with grappling hook, disguise kit etc)
at 13th, gain advantage to disable magic locks and you can use you thieve's tool to ''hack'' portals sigil. Your animated tools can cast Dispel Magic, if the spell effect is disrupted, all enemies within 15 ft of it take Xd6 force damage.
17th, you can regain 4 scaps at the end of a short rest.