Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/rosenfan/matrix/matrix-designnpx skills add Rosenfan/Matrix --skill matrix-designgit clone --depth 1 https://github.com/Rosenfan/MatrixWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/rosenfan/matrix/matrix-design)<a href="https://agentmods.dev/skills/rosenfan/matrix/matrix-design"><img src="https://agentmods.dev/badge/skills/rosenfan/matrix/matrix-design.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00028 | $0.00760 |
| Opus 5 | $0.00014 | $0.00380 |
| Sonnet 5 | $0.00006 | $0.00152 |
| Haiku 4.5 | $0.00003 | $0.00076 |
Grade A, and why
matrix-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Matrix Design
Design is used by full and resumable legacy shortcut changes only. A new lightweight hotfix/tweak moves directly from Open to Build and must not create Design artifacts merely to satisfy the full guard.
Use artifact_language from node <matrix-skill-directory>/scripts/matrix-runtime.mjs inspect for all design and plan prose. Keep Runtime-required English heading tokens unchanged.
Run node <matrix-skill-directory>/scripts/matrix-runtime.mjs inspect, read the active proposal and frozen orchestration, then write artifacts/design.md with ## Decisions, ## Boundaries, ## Test seams, and ## Risks; write artifacts/plan.md with ## Steps, ## Validation, and ## Stop conditions.
Prim
Use Matrix's own capability to investigate the repository and design the change.
Arch
Invoke only capabilities whose task-fact trigger is proven:
domain-modelingfor unclear vocabulary, invariants, or architectural decisions;researchwhen required external facts cannot be established from the repository;prototypewhen a material design decision needs disposable empirical evidence;codebase-designwhen a deep-module, interface, or test-seam decision remains;writing-for-agentswhen the Contract creates or changes Skills,AGENTS.md,CLAUDE.md, or documents reached through agent pointers.
Order follows actual dependencies; never run a fixed companion sequence. Announce each invocation and reason. A correctly installed capability gets at most one same-capability Matrix fallback; installation-integrity failure stops the phase.
Long-lived domain, ADR, or research artifacts follow repository conventions, and material conclusions must be synchronized into the canonical design or plan. Prototypes default to an OS temporary directory unless the approved design promotes a project path. Companion output cannot own Matrix state or create a competing plan.
wayfinder and improve-codebase-architecture are explicit handoffs outside the active Design. Recommend one only when its purpose fits, then let the user invoke it; a selected result may enter a separate governed Change.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- today Changed · +2 lines 729059dc4d9f
- 4d ago First seen · 72 lines · 28 tokens per session scan A 6bd455630bdb
matrix-design is a skill published in the GitHub repository Rosenfan/Matrix (5 stars, last pushed 3d ago), licensed MIT. It adds 28 tokens to every session and 760 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
brainstorming
You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.
auto-perf-optimize
Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.
chat-perf
Run chat perf benchmarks and memory leak checks against the local dev build or any published VS Code version. Use when investigating chat rendering regressions, validating perf-sensitive changes to chat UI, or checking for memory leaks in the chat response pipeline.
chat-pet-sprite-creation
Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…