Ratatoskr-mcp: Instructions file for Codex

AGENTS.md

Ratatoskr-mcp AGENTS.md is an instructions file for Codex, OpenCode from edk4971/Ratatoskr-mcp. It costs 1,113 tokens per session, scanned A, original, Unlicense.

Project instructions for Ratatoskr-mcp, an MCP server that retrieves Wikipedia articles from local dump files instead of the internet. They describe its four-file structure and how a request is processed.

In plain words
What is it for?
Understanding, modifying, and troubleshooting the Ratatoskr-mcp Wikipedia retrieval server and its local data flow.
Why use it?
They give a coding agent the project context needed to make changes without guessing how the server, index, decompression, and article parsing fit together.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: mentions OpenCode.

This is edk4971/Ratatoskr-mcp's own configuration. It tells Codex and OpenCode how to work on Ratatoskr-mcp 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 Ratatoskr-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to edk4971/Ratatoskr-mcp. 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/edk4971/Ratatoskr-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/edk4971/Ratatoskr-mcp

Made for: Codex, OpenCode.

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 Ratatoskr-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/edk4971/ratatoskr-mcp/agents-md.svg)](https://agentmods.dev/instructions/edk4971/ratatoskr-mcp/agents-md)
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<a href="https://agentmods.dev/instructions/edk4971/ratatoskr-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/edk4971/ratatoskr-mcp/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,113 This file is loaded in full into every session.
When invoked 1,113 The same file — it is already loaded in full.
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 $0.01113 $0.01113
Opus 5 $0.00557 $0.00557
Sonnet 5 $0.00223 $0.00223
Haiku 4.5 $0.00111 $0.00111

Measured 7d ago against content hash 0a3d63bac5d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

Ratatoskr-mcp AGENTS.md 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 7d 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.md · 53 lines

How it starts

The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Project: Ratatoskr-mcp

What this is

An MCP (Model Context Protocol) server that retrieves Wikipedia articles from local multistream dump files. No database, no ingest step, no internet required at query time. Named after Ratatoskr, the squirrel of Norse mythology who runs up and down Yggdrasil carrying messages.

Objective

Sub-3-second response time for article retrieval. Currently hitting 0.3–0.6s.

Architecture (4 files, flat — no subpackages)

  • server.py — MCP server entry point using fastmcp with SSE transport. Exposes one tool: get_wikipedia_article(topic).
  • index.py — Flat-file index lookup. find_page(title) -> (byte_offset, stream_id, title). Uses ripgrepy for 0.2s case-insensitive search of the 1.2GB multistream index, rapidfuzz for fuzzy fallback.
  • retrieval.py — Orchestrates: find_page → seek bz2 block → decompress → parse → follow redirects → assemble Markdown output.
  • parser.py — XML parsing (lxml) + wikitext parsing (mwparserfromhell). Extracts title, lead section, infobox. Detects <redirect> elements.

Data flow

  1. Index lookup (index.py): ripgrepy searches the plaintext index file (byte_offset:stream_id:title format) for the query. Exact case-sensitive match → exact case-insensitive match → fuzzy match (cluster hits by byte_offset, score each cluster with rapidfuzz word-boundary scoring).
  2. Block fetch (retrieval.py): seek to byte_offset in the bz2 dump, read 32MB chunk, decompress single bz2 block.
  3. XML parse (parser.py): find the matching <page> element (two-pass: case-sensitive then case-insensitive, to avoid grabbing redirect pages with different casing).
  4. Redirect (parser.py/retrieval.py): if <redirect title="X" /> present, recurse with X (max depth 5, loop detection via visited-title set).
  5. Extract (parser.py): parse wikitext with mwparserfromhell. Extract infobox template, then lead section via get_sections(include_lead=True, flat=True).
  6. Output: # Title\n\n{body}\n\n---\n\n{infobox} — body first (lead section only), infobox after as reference.

Read the full file on GitHub · 53 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. 7d ago First seen · 53 lines · 1,113 tokens per session scan A 0a3d63bac5d0

Subscribe to this mod's changes

Ratatoskr-mcp AGENTS.md is an instructions file published in the GitHub repository edk4971/Ratatoskr-mcp (0 stars, last pushed 27d ago), licensed Unlicense. It adds 1,113 tokens to every session, about $0.0056 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 2026-08-31.

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