Community Extensibility

Start Here

Most contributions touch one of two surfaces. Try these before reading the full matrix below:

1. Add guidance to an existing workflow -> drop a topic-scoped Markdown file in skills/<skill>/references/ (or shared references/). No code, no schema; just stable headings and a link/path check.
2. Add a report style -> add a directive-only templates/style/<style>.md and route it in templates/style/routing.md. Style files own visual grammar, not runnable skeletons.

Reach for the full surface matrix only when you add executable behavior (scripts, hooks), a maturity model or detector, a host adapter, or packaging.

To add a Coding Agent host, start with Contributing a New Coding Agent Host. It turns the matrix row into an evidence, implementation, cross-platform, and review workflow without making every support slice mandatory.

Extensible Surfaces

This is the complete reference. For the common cases, see Start Here above.

Surface	Extensible by community	Canonical owner	Contract required	Activation path	Validation evidence
Shared workflow	Yes	skills/<skill>/	SKILL.md frontmatter and concise workflow; optional references/ for conditional detail	Triggered by the host skill loader or packaged plugin	quick_validate.py, realistic prompt smoke, path checks
Skill detail and reusable guidance	Yes	skills/<skill>/references/ or shared references/	Topic-scoped Markdown with stable headings and source boundaries	Loaded only when the skill or agent task needs it	Link/path check; consumer grep for any 2+ consumer claim
Maturity model	Yes, additive only	models/<model>.md plus models/routing.md	Stable model_id, aliases, audience, levels, dimensions, evidence sources, scoring and confidence rules	Selectable through model routing after routing-file registration	Model-routing checks, fixture/report sample, no mutation of built-in defaults unless intentional