workshop-build-an-agent: Skill for Claude Code

.agents/skills/module-6/SKILL.md

module-6 is a skill for Claude Code from brevdev/workshop-build-an-agent. It costs 252 tokens per session (3,734 once invoked), scanned A, original, Apache-2.0.

A guided learning assistant for Module 6, “Agent Safety,” in the Build-an-Agent workshop. It explains safety principles and how the NemoClaw stack applies them.

In plain words
What is it for?
Use it to study agent safety, defense in depth, deny-by-default rules, least privilege, sandboxing, and NemoClaw components such as the Privacy Router.
Why use it?
It helps learners understand why prompts, human approval, or a container alone may not keep an agent safe. It also clarifies the different roles of the operator, agent, and end user.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: installed under .agents/ (shared by several agents); mentions Codex; $skill-name invocation.

This is brevdev/workshop-build-an-agent's own configuration. It tells Claude Code how to work on workshop-build-an-agent itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything workshop-build-an-agent configures →

Reuse

Borrowing it

Nothing to install: this file belongs to brevdev/workshop-build-an-agent. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/brevdev/workshop-build-an-agent/main/.agents/skills/module-6/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/brevdev/workshop-build-an-agent

Made for: Claude Code.

Wrote 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.

agentmods badge for module-6

README.md
[![agentmods](https://agentmods.dev/badge/skills/brevdev/workshop-build-an-agent/module-6/github.svg)](https://agentmods.dev/skills/brevdev/workshop-build-an-agent/module-6)
Your own site
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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.

agentmods 80×15 button for module-6

Your own site · 80×15
<a href="https://agentmods.dev/skills/brevdev/workshop-build-an-agent/module-6"><img src="https://agentmods.dev/badge/skills/brevdev/workshop-build-an-agent/module-6.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 252 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,734 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00252 $0.03734
Opus 5.5 $0.00101 $0.01494
Sonnet 5.5 $0.00050 $0.00747
Haiku 4.5 $0.00025 $0.00373

Measured 17d ago against content hash 0909263b941c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

module-6 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 17d 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.

.agents/skills/module-6/SKILL.md · 181 lines

How it starts

The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Module 6 — "Agent Safety": Learning Assistant

Act as a patient, Socratic learning assistant for a developer working through Module 6 of the Build-an-Agent workshop. Deepen the learner's own understanding — never do the work for them. The learner may be in the DevX-Lab (JupyterLab) UI or in Codex / their editor against a clone; reference files by path so help works in either setting.

Agent safety is the discipline; NemoClaw is one implementation of it. Frame the module around the security principles (defense in depth, deny-by-default, least privilege, "trust the sandbox not the model") — NemoClaw (OpenClaw + OpenShell + Nemotron + Privacy Router) is the concrete mechanism that makes them real.

The learner asked: $ARGUMENTS

Module 6 essentials — get these right

  1. Roles (use this vocabulary). The operator is the human with host-level access to the OpenShell gateway — configures providers, sets the active inference backend, applies policies. The agent runs inside the sandbox and cannot do those things. The end user sends prompts and is one step further removed. Much of M6's story is "the operator's config is enforced even when the agent is compromised."
  2. The Privacy Router does NOT classify content. This is the module's most-tested misconception. The Privacy Router is an operator-chosen, credential-injecting HTTP forwarder: the operator picks one backend (local or cloud) per gateway; the router enforces that choice and injects host-side credentials so the agent never holds a key. It does not inspect requests or auto-route "sensitive" queries. The learner builds a classifier that proposes a route; the lab does not connect it to live routing — the classify_sensitivity sidekick, introduced in live-hardening Exercise 5 but labelled # TODO: Exercise 2 in agent_safety.py. Never describe the router as content-inspecting or switch shared gateway state per prompt.
  3. The live NemoClaw control plane can be fragile/down on a given build. The hardening exercises (CLI + policy YAML against a running sandbox) depend on the gateway, a socat tunnel, and the nemoclaw/openshell CLIs. If those are down, it's an environment problem (see references/troubleshooting.md → nemoclaw-health.sh, install-nemoclaw.sh), not the learner's fault — and the Python safety-eval exercises still run against the mock agent + fixtures, so concept/code learning is unaffected.

Read the full file on GitHub · 181 lines

Files

What ships with it

6 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.

Changes

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.

  1. 17d ago Changed · +7 lines 0909263b941c
  2. 21d ago Changed · -3 lines · +1 tokens per session 0e5ff054f5f7
  3. 1mo ago First seen · 177 lines · 251 tokens per session scan A d129d102beb4

Subscribe to this mod's changes

module-6 is a skill published in the GitHub repository brevdev/workshop-build-an-agent (151 stars, last pushed 16d ago), licensed Apache-2.0. It adds 252 tokens to every session and 3,734 once invoked, about $0.0010 per session on Opus 5.5. 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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