agentmods.dev

CustomerNewsletter: Agent for Claude Code

.github/agents/skill-builder.agent.md

skill-builder is an agent for Claude Code from briancl2/CustomerNewsletter. It costs 29 tokens per session (488 once invoked), scanned A, original, MIT.

An agent that builds individual skills for a customer-newsletter pipeline from existing agent logic, prompts, and benchmark examples. A benchmark is a known example used to check whether the result is correct.

In plain words
What is it for?
Use it with /fleet when creating a skill for a particular newsletter-pipeline phase.
Why use it?
It turns scattered instructions and examples into a consistent skill with documented inputs, outputs, workflow, and completion checks.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

This is briancl2/CustomerNewsletter's own configuration. It tells Claude Code how to work on CustomerNewsletter 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 CustomerNewsletter configures →

not rated 11repo 5mo ago A scan 29 tokens original MIT
View source ↗ briancl2/CustomerNewsletter briancl2.github.io
Reuse

Borrowing it

Nothing to install: this file belongs to briancl2/CustomerNewsletter. 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/briancl2/CustomerNewsletter/main/.github/agents/skill-builder.agent.md
Clone the repo
git clone --depth 1 https://github.com/briancl2/CustomerNewsletter

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 skill-builder

README.md
[![agentmods](https://agentmods.dev/badge/agents/briancl2/customernewsletter/skill-builder/github.svg)](https://agentmods.dev/agents/briancl2/customernewsletter/skill-builder)
Your own site
<a href="https://agentmods.dev/agents/briancl2/customernewsletter/skill-builder"><img src="https://agentmods.dev/badge/agents/briancl2/customernewsletter/skill-builder/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.

agentmods 80×15 button for skill-builder

Your own site · 80×15
<a href="https://agentmods.dev/agents/briancl2/customernewsletter/skill-builder"><img src="https://agentmods.dev/badge/agents/briancl2/customernewsletter/skill-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 29 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 488 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.
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 $0.00029 $0.00488
Opus 5.5 $0.00012 $0.00195
Sonnet 5.5 $0.00006 $0.00098
Haiku 4.5 $0.00003 $0.00049

Measured 2mo ago against content hash c3382a1542c2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

skill-builder 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.

.github/agents/skill-builder.agent.md · 41 lines

What it actually says

How You Work

You receive a task specifying which skill to build. For that skill you:

  1. Read the building-skill spec at .github/skills/building-skill/SKILL.md
  2. Read the agent file at .github/agents/customer_newsletter.agent.md — extract the section relevant to your assigned phase
  3. Read the prompt file for your phase in .github/prompts/
  4. Read the benchmark example(s) in your skill's examples/ directory
  5. Write SKILL.md following the building-skill spec — workflow, references, done-when criteria
  6. Write reference files in references/ — domain rules extracted from agent and prompt
  7. DO NOT modify files outside your assigned skill directory

Quality Standards

  • SKILL.md frontmatter must have: name, description (with keywords), metadata.category
  • SKILL.md body: Quick Start, Core Workflow, Reference links, Done When
  • References: extract domain rules, formatting specs, taxonomy tables from agent/prompt
  • Keep SKILL.md under 300 lines; put detail in references/
  • Include input/output specification matching the pipeline table
  • Match tone and structure of the building-skill spec

Key Context

  • Audience: Enterprise engineering leaders (Healthcare, Manufacturing, Financial Services)
  • Category taxonomy: Security & Compliance, AI & Automation, Platform & DevEx, Enterprise Administration
  • Event categories: Copilot, GitHub Platform, Developer Experience, Enterprise
  • Plans to exclude: Copilot Free/Individual/Pro/Pro+
  • Formatting: No em dashes, no raw URLs, bold product names, [Text](URL) links only
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. 2mo ago First seen · 41 lines · 29 tokens per session scan A c3382a1542c2

Subscribe to this mod's changes

skill-builder is an agent published in the GitHub repository briancl2/CustomerNewsletter (11 stars, last pushed 5mo ago), licensed MIT. It adds 29 tokens to every session and 488 once invoked, about $0.0001 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.

Building agentsagentic-workflowsagentscopilotllmopsmkdocsnewsletter
Related

skill-builder compared with agents from other repositories

skill-builder next to 6 agents from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
skill-builderbriancl2/CustomerNewsletterAgent115mo agoMITA29Claude Code
analyzerfeiskyer/claude-code-settingsAgent1.7kyesterdayMITA29Claude Code
insight-documenterfeiskyer/claude-code-settingsAgent1.7kyesterdayMITA36Claude Code
instruction-reflectorfeiskyer/claude-code-settingsAgent1.7kyesterdayMITA42Claude Code
security-champion-agentnavikt/copilotAgent60yesterdayMITA25Claude Code
code-reviewnavikt/copilotAgent60yesterdayMITA28Claude Code
accessibility-agentnavikt/copilotAgent60yesterdayMITA32Claude Code