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-opennpx skills add Rosenfan/Matrix --skill matrix-opengit 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-open)<a href="https://agentmods.dev/skills/rosenfan/matrix/matrix-open"><img src="https://agentmods.dev/badge/skills/rosenfan/matrix/matrix-open.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 | $0.00038 | $0.00578 |
| Opus 5 | $0.00019 | $0.00289 |
| Sonnet 5 | $0.00008 | $0.00116 |
| Haiku 4.5 | $0.00004 | $0.00058 |
Grade A, and why
matrix-open 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 — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Matrix Open
Run node <matrix-skill-directory>/scripts/matrix-runtime.mjs inspect and follow its profile and evidence_policy.
Use its artifact_language for all proposal prose. Keep the required English heading tokens exactly as specified for Runtime guards; only the text beneath them is localized.
- full: produce
proposal.mdwith## Goal,## Scope,## Non-goals,## Acceptance, and## Risks, then continue to Design. - lightweight: produce the complete compact Contract before editing project implementation. Include
## Goal,## Scope,## Non-goals,## Approach,## Acceptance,## Validation,## Risks, and## Upgrade conditions. - hotfix evidence: also include
## Expected behavior,## Actual behavior, and## Reproduction. - tweak evidence: also include
## Current behavior,## Preserved behavior, and## Diff boundary.
Prim
Use Matrix's own capability to clarify the request and write the proposal.
Arch
Invoke grilling only when material ambiguity remains or the user asks to stress-test the request. Invoke domain-modeling only when domain vocabulary, invariants, or an architectural decision is unclear. Announce the capability and reason before invoking it; selecting Arch already authorizes triggered capabilities.
If progress is blocked by facts or decisions owned by another person, explain why to-questionnaire fits and ask the user to invoke it. Do not invoke the wrapper yourself.
Companion output is evidence for the Matrix proposal. It must not create another workflow, proposal, confirmation state, or phase transition. If a correctly installed capability fails, perform at most one Matrix-owned fallback for that same capability and record the failure and evidence. Installation-integrity failures require matrix init --with-mattpocock and are not eligible for fallback.
Process
- Resolve only ambiguities required by the active workflow.
- Write the canonical proposal and synchronize material companion conclusions into it.
- For full, ask for confirmation when scope or risk is material, then enter Design.
- For lightweight, always present the compact Contract and wait for explicit confirmation before entering Build.
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 32929071cd40
- 4d ago First seen · 41 lines · 38 tokens per session scan A c688540bad6a
matrix-open is a skill published in the GitHub repository Rosenfan/Matrix (5 stars, last pushed 2d ago), licensed MIT. It adds 38 tokens to every session and 578 once invoked, about $0.0002 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…