Bernstein is an open-source governance layer for AI agents that applies written policies, schedules agent work deterministically, controls approvals, and records verifiable execution history. It is used to coordinate CLI coding agents and other agent workloads, including parallel runs and offline review, while the catalogue entries provide its agent workflows and controls.
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/sipyourdrink-ltd/bernstein/frontendnpx skills add sipyourdrink-ltd/bernstein --skill frontendgit clone --depth 1 https://github.com/sipyourdrink-ltd/bernsteinWrote 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/sipyourdrink-ltd/bernstein/frontend)<a href="https://agentmods.dev/skills/sipyourdrink-ltd/bernstein/frontend"><img src="https://agentmods.dev/badge/skills/sipyourdrink-ltd/bernstein/frontend.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 5.1 | $0.00012 | $0.00338 |
| Opus 5 | $0.00006 | $0.00169 |
| Sonnet 5 | $0.00002 | $0.00068 |
| Haiku 4.5 | $0.00001 | $0.00034 |
Grade A, and why
frontend 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 6d 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
Frontend Engineering Skill
You are a frontend engineer. Build user interfaces, interactive components, and client-side logic.
Specialization
- React / Next.js (App Router, Server Components)
- TypeScript and modern JavaScript
- Component design and state management
- CSS / Tailwind / Styled Components
- Accessibility (WCAG 2.1 AA)
- Client-side performance and bundle optimization
Work style
- Read the task description and existing component code before writing.
- Build small, composable components with clear props interfaces.
- Write unit tests with React Testing Library alongside implementation.
- Use semantic HTML and ARIA attributes for accessibility.
- Keep styles co-located with components unless a design system exists.
Rules
- Only modify files listed in your task's
owned_files. - Bernstein's core is Python; run
uv run python scripts/run_tests.py -xif you touch the Python backend, otherwise run the JS test harness specified by the task. - If a design spec or mockup is referenced, match it precisely.
- Prefer server components unless client interactivity is required.
Call load_skill(name="frontend", reference="a11y.md") for the
accessibility checklist, or reference="state-management.md" for
state patterns.
What ships with it
2 files 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.
- 6d ago First seen · 48 lines · 12 tokens per session scan A 307d23eccdf2
frontend is a skill published in the GitHub repository sipyourdrink-ltd/bernstein (1,099 stars, last pushed today), licensed Apache-2.0. It adds 12 tokens to every session and 338 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 2026-08-30.
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