ai-engineer

ai-engineer is a skill for Claude Code from skillmds/skillmd. It costs 36 tokens per session (1,222 once invoked), scanned A, original, MIT.

A guide for building applications that use large language models (LLMs), including chatbots, retrieval-augmented generation (RAG), and AI agents. It covers architecture, model integration, testing, monitoring, safety, and cost controls.

In plain words
What is it for?
Use it to design LLM applications, connect models to data through RAG, build vector search and agent workflows, and plan testing or staged releases.
Why use it?
It helps turn an AI feature into a deployable system instead of leaving model choice, data handling, safety, and reliability unclear.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the build-multi-agent-system-with-crewai plugin — 11 skills shipped together

Good fit Use it to design LLM applications, connect models to data through RAG, build vector search and agent workflows, and plan testing or staged releases.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/skillmds/skillmd/rootcastleco-ai-engineer
Install

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.

Any agent
npx skills add skillmds/skillmd --skill rootcastleco-ai-engineer
Clone the repo
git clone --depth 1 https://github.com/skillmds/skillmd

Made for: Claude Code.

Or install build-multi-agent-system-with-crewai, the plugin that ships this one along with the rest of its 11 skills.

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 ai-engineer

README.md
[![agentmods](https://agentmods.dev/badge/skills/skillmds/skillmd/rootcastleco-ai-engineer/github.svg)](https://agentmods.dev/skills/skillmds/skillmd/rootcastleco-ai-engineer)
Your own site
<a href="https://agentmods.dev/skills/skillmds/skillmd/rootcastleco-ai-engineer"><img src="https://agentmods.dev/badge/skills/skillmds/skillmd/rootcastleco-ai-engineer/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 ai-engineer

Your own site · 80×15
<a href="https://agentmods.dev/skills/skillmds/skillmd/rootcastleco-ai-engineer"><img src="https://agentmods.dev/badge/skills/skillmds/skillmd/rootcastleco-ai-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,222 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 $0.00036 $0.01222
Opus 5.5 $0.00014 $0.00489
Sonnet 5.5 $0.00007 $0.00244
Haiku 4.5 $0.00004 $0.00122

Measured 1mo ago against content hash 1e5f9024a3a9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ai-engineer 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 1mo 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.

plugins/build-multi-agent-system-with-crewai/skills/rootcastleco-ai-engineer/SKILL.md · 139 lines

How it starts

The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an AI engineer specializing in production-grade LLM applications, generative AI systems, and intelligent agent architectures.

Use this skill when

  • Building or improving LLM features, RAG systems, or AI agents
  • Designing production AI architectures and model integration
  • Optimizing vector search, embeddings, or retrieval pipelines
  • Implementing AI safety, monitoring, or cost controls

Do not use this skill when

  • The task is pure data science or traditional ML without LLMs
  • You only need a quick UI change unrelated to AI features
  • There is no access to data sources or deployment targets

Instructions

  1. Clarify use cases, constraints, and success metrics.
  2. Design the AI architecture, data flow, and model selection.
  3. Implement with monitoring, safety, and cost controls.
  4. Validate with tests and staged rollout plans.

Safety

  • Avoid sending sensitive data to external models without approval.
  • Add guardrails for prompt injection, PII, and policy compliance.

Model Selection Decision Matrix

Need Recommended Why
Best quality, complex reasoning Claude Opus / GPT-4o Highest capability, higher cost
Fast + cheap, simple tasks Claude Haiku / GPT-4o-mini Low latency, low cost
Privacy / on-prem required Llama 3.2 via Ollama or vLLM No data leaves your infrastructure
Structured outputs OpenAI w/ response_format or Anthropic w/ tool_use Native JSON schema enforcement
Multi-step agents LangGraph or CrewAI Built-in state management and tool orchestration

RAG Architecture Checklist

  1. Chunking — Choose strategy based on document type:

    • Prose → recursive text splitter (500-1000 tokens, 100 token overlap)
    • Code → AST-aware splitting by function/class
    • Tables → preserve row structure, embed headers with each chunk
  2. Embedding — Match model to use case:

    • General: text-embedding-3-small (cost-effective) or text-embedding-3-large (higher quality)
    • Domain-specific: fine-tune on your corpus with sentence-transformers

Read the full file on GitHub · 139 lines

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. 1mo ago First seen · 139 lines · 36 tokens per session scan A 1e5f9024a3a9

Subscribe to this mod's changes

ai-engineer is a skill published in the GitHub repository skillmds/skillmd (143 stars, last pushed 4d ago), licensed MIT. It adds 36 tokens to every session and 1,222 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 2026-09-19.

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