ystack began as a portable Agent Skills adaptation of Cursor pstack by Lauren Tan (poteto).
Upstream pstack is Cursor-oriented. ystack preserves its engineering discipline—principles, playbooks, verification gates—and adds a capability contract, host adapters, portability checks, model-role configuration, and portable-only workflows such as living-spec.
The public project name is ystack. References to pstack remain where they identify the upstream project or provide compatibility for existing commands, paths, and model configuration.
Original work: MIT License, Copyright (c) 2026 Lauren Tan.
ystack adaptation: MIT License, see LICENSE.