Originally published on LinkedIn on October 15, 2025.
This article introduces an experimental repository for extending GitHub Spec Kit with community-contributed commands. I previously published work on a “/cross-feature” command applying systems thinking across features and needed infrastructure for iterating on experimental functionality.
Key Motivation Points
I identified three main reasons for creating this extension space:
- Context-specific commands - Some commands may be better suited as opt-in rather than core features
- Rapid iteration - Provides “a low-friction way to trial commands before they’re upstreamed”
- Development efficiency - Avoids manual file copying during experimentation phases
Technical Conventions
To differentiate extension commands from standard GitHub Spec Kit offerings, I use a “/speckit.extn” prefix structure. The cross-feature command example follows this as “/speckit.extn.cross-feature”.
Setup Instructions
The process involves two steps:
- Initialize Spec Kit using the provided uvx command
- Install extensions via the provided installation script
Resources
- Experimental Repository: https://github.com/polarizertech/spec-kit-extensions
- Related Discussion: GitHub issue #729 and discussion #898
I welcome feedback on naming conventions, command flags, and installation experience.