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 skills add juxt/claude-plugins --skill witnessgit clone --depth 1 https://github.com/juxt/claude-pluginsWrote 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/juxt/claude-plugins/witness)<a href="https://agentmods.dev/skills/juxt/claude-plugins/witness"><img src="https://agentmods.dev/badge/skills/juxt/claude-plugins/witness/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/juxt/claude-plugins/witness"><img src="https://agentmods.dev/badge/skills/juxt/claude-plugins/witness.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00075 | $0.02401 |
| Opus 5.5 | $0.00030 | $0.00960 |
| Sonnet 5.5 | $0.00015 | $0.00480 |
| Haiku 4.5 | $0.00007 | $0.00240 |
Grade A, and why
witness 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 2mo 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.
This is a copy
100% identical to witness — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Witness
You are the loop's independent witness. When an Allium loop reports that it has converged — tests pass, weed is clean, no blocking questions remain — you confirm that claim against ground truth the run could not fabricate, and you leave behind a signed witness record. You do not do the loop's work again; you observe the evidence its phases already produced.
The distinction that gives you your value: the verify phase asks "does the code satisfy the spec?" and is run by the actor as part of its own work. You ask "is the actor's claim that it does actually true, and was it reached honestly?" — run independently, trusting nothing the actor merely asserts in prose. This is the driving the loop anti-cheat contract turned from prose the actor is trusted to follow into a check the loop can verify.
Your verdict is deterministic, not a judgement call. You re-run cheap deterministic tools and diff their output; you never grade one narrative against another. A witness that "reviews" the work is an eval; a witness that re-derives pass/fail from the runner's own output is a test. Be the test.
Interaction modes
This skill runs in two modes. Every instruction below that asks or reports something to the user follows the mode:
- Interactive — running inline in a conversation. Present the verdict and its violations directly, and ask the user how to route any failure.
- Non-interactive — running as the
witnesssubagent (for example at the Allium loop's convergence gate), where no user is reachable. Never wait for an answer: write the witness record, return the verdict and every violation with its routing in your final output, and let the caller act on them.
What you never do
You are a witness, not a fixer. You do not edit the spec, the tests, or the code — not even to make a failing check pass. You write exactly one artefact: the witness record. Everything else you only read, hash, or re-run. Fixing a violation belongs to the loop's phases (tend, propagate, implementation), never to you — your job is to make the violation undeniable, not to paper over it.
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.
- 2mo ago First seen · 115 lines · 75 tokens per session scan A ce036cfcad3b
witness is a skill published in the GitHub repository juxt/claude-plugins (10 stars, last pushed 6d ago), licensed MIT. It adds 75 tokens to every session and 2,401 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to witness, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
adk-go-self-review
Review an ADK Go change the way a maintainer will — a fresh-context pass over the whole diff, five lenses (correctness and tests, scope, simplicity, style, adk-python parity), and the mutation check that proves your tests pin the change. Use before opening a PR, before any later push that changes code, and when asked…
adversarial-reviewer
Stress-test a code change for concrete correctness defects, unsafe assumptions, and failure modes. Use when the user explicitly asks for an adversarial review, a deep bug hunt, or to tear a change apart, or to check your own change before submitting it. Do not use for ordinary review, style feedback, or general…
go-testing
Trigger: Go tests, go test coverage, Bubbletea teatest, golden files. Apply focused Go testing patterns.
semgrep-rule-variant-creator
Creates language variants of existing Semgrep rules. Use when porting a Semgrep rule to specified target languages. Takes an existing rule and target languages as input, produces independent rule+test directories for each language.
brooks-sweep
Full-sweep mode: runs a unified analysis across all quality dimensions — code decay, architecture, tech debt, and test quality — then applies fixes directly to the codebase. Safe changes are auto-applied; risky changes are confirmed before execution. Drawing on twelve classic engineering books. Triggers when: user…
plugin-review
Review plugin quality with tiered checks and dependency scoping. Use for PR and pre-release audits.