rag-implementation

rag-implementation is a skill for Claude Code, Codex from NOMARJ/sigil. It costs 49 tokens per session (4,038 once invoked), scanned A, original, Apache-2.0.

A guide to building Retrieval-Augmented Generation, or RAG, systems that find relevant outside information before a language model writes an answer.

In plain words
What is it for?
Use it for document question-answering, documentation assistants, semantic search, research tools, and chatbots connected to a knowledge base.
Why use it?
It helps ground AI responses in current or private documents and can reduce made-up answers by supplying supporting context.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it for document question-answering, documentation assistants, semantic search, research tools, and chatbots connected to a knowledge base.

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Install with agentmods
npx agentmods add skills/nomarj/sigil/rag-implementation
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 NOMARJ/sigil --skill rag-implementation
Clone the repo
git clone --depth 1 https://github.com/NOMARJ/sigil

Made for: Claude Code, Codex.

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 rag-implementation

README.md
[![agentmods](https://agentmods.dev/badge/skills/nomarj/sigil/rag-implementation.svg)](https://agentmods.dev/skills/nomarj/sigil/rag-implementation)
Your own site
<a href="https://agentmods.dev/skills/nomarj/sigil/rag-implementation"><img src="https://agentmods.dev/badge/skills/nomarj/sigil/rag-implementation.svg" alt="Measured on agentmods" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,038 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 $0.00049 $0.04038
Opus 5 $0.00024 $0.02019
Sonnet 5 $0.00010 $0.00808
Haiku 4.5 $0.00005 $0.00404

Measured 5d ago against content hash d5291ecdfa63, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

rag-implementation 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 5d 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.

packs/data/skills/llm/rag-implementation/SKILL.md · 571 lines

How it starts

The opening of the file, as written. The whole thing — 571 lines — stays where its author put it; the contents beside it link to each section on GitHub.

RAG Implementation

Master Retrieval-Augmented Generation (RAG) to build LLM applications that provide accurate, grounded responses using external knowledge sources.

When to Use This Skill

  • Building Q&A systems over proprietary documents
  • Creating chatbots with current, factual information
  • Implementing semantic search with natural language queries
  • Reducing hallucinations with grounded responses
  • Enabling LLMs to access domain-specific knowledge
  • Building documentation assistants
  • Creating research tools with source citation

Core Components

1. Vector Databases

Purpose: Store and retrieve document embeddings efficiently

Options:

  • Pinecone: Managed, scalable, serverless
  • Weaviate: Open-source, hybrid search, GraphQL
  • Milvus: High performance, on-premise
  • Chroma: Lightweight, easy to use, local development
  • Qdrant: Fast, filtered search, Rust-based
  • pgvector: PostgreSQL extension, SQL integration

2. Embeddings

Purpose: Convert text to numerical vectors for similarity search

Models (2026):

Model Dimensions Best For
voyage-3-large 1024 Claude apps (Anthropic recommended)
voyage-code-3 1024 Code search
text-embedding-3-large 3072 OpenAI apps, high accuracy
text-embedding-3-small 1536 OpenAI apps, cost-effective
bge-large-en-v1.5 1024 Open source, local deployment
multilingual-e5-large 1024 Multi-language support

3. Retrieval Strategies

Approaches:

  • Dense Retrieval: Semantic similarity via embeddings
  • Sparse Retrieval: Keyword matching (BM25, TF-IDF)
  • Hybrid Search: Combine dense + sparse with weighted fusion
  • Multi-Query: Generate multiple query variations
  • HyDE: Generate hypothetical documents for better retrieval

4. Reranking

Purpose: Improve retrieval quality by reordering results

Methods:

  • Cross-Encoders: BERT-based reranking (ms-marco-MiniLM)
  • Cohere Rerank: API-based reranking
  • Maximal Marginal Relevance (MMR): Diversity + relevance
  • LLM-based: Use LLM to score relevance

Read the full file on GitHub · 571 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. 5d ago First seen · 571 lines · 49 tokens per session scan A d5291ecdfa63

Subscribe to this mod's changes

rag-implementation is a skill published in the GitHub repository NOMARJ/sigil (5 stars, last pushed 2d ago), licensed Apache-2.0. It adds 49 tokens to every session and 4,038 once invoked, about $0.0002 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 2026-09-03.