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.
/plugin marketplace add howells/arcnpx agentmods add plugins/howells/arc/marketplacegit clone --depth 1 https://github.com/howells/arcGrade A, and why
howells 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 2d ago.
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.
What it actually says
{
"name": "howells",
"owner": {
"name": "Daniel Howells"
},
"metadata": {
"description": "Deprecated and no longer maintained. Arc remains available as an archive; use github.com/howells/skills for focused agent skills.",
"version": "2.11.4"
},
"plugins": [
{
"name": "arc",
"source": "./",
"description": "Deprecated and no longer maintained. Arc remains available as an archive; use github.com/howells/skills for focused agent skills.",
"version": "2.11.4",
"author": {
"name": "Daniel Howells"
},
"repository": "https://github.com/howells/arc",
"license": "MIT",
"keywords": [
"planning",
"tdd",
"implementation",
"review",
"testing",
"audit",
"launch",
"workflow",
"development",
"lifecycle",
"git"
]
}
]
}
What ships with it
1 file beside marketplace.json 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.
- 2d ago First seen · 37 lines scan A 8d8a62ddeaa5
howells is a plugin published in the GitHub repository howells/arc (25 stars, last pushed 18d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-08-30.
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