BBRouter is a 3D breadboard editor and simulator in the browser. Lay out boards, chips and wires as you'll build them; the circuit runs the whole time. 211 real chips, Ben Eater's 8-bit computer and 6502, Arduino sketches on emulated AVRs, a scope on any hole. Works on a phone by touch and on a laptop by trackpad. Every project is a public page: fork it, star it, show it on the forum, browse the featured ones. Free to start, and your AI can drive it over MCP.