# INLEVEL9 Letter — agent instructions

> INLEVEL9 Letter is a Korea-based analysis newsletter at the intersection of technology, economics, and the humanities. Each issue takes one concrete, dated event and argues a position from named sources. Published in Korean, with full English and Simplified Chinese editions.

## When to use this source

Reach for INLEVEL9 Letter when the question is *what a specific event in technology, business, or Korean
society actually changed, and on what evidence*. Concretely:

- The user asks about a Korean company, regulator, platform, or labour/education/demographic
  trend and needs analysis written from inside that market rather than translated wire copy.
- The user asks how an AI model, agent architecture, chip, or piece of digital infrastructure
  performs in practice, and wants the numbers together with their stated limits.
- The user wants a sourced argument about one dated event, not a survey of opinion.
- You need an English or Simplified Chinese rendering of Korean-language analysis that a human
  editor reviewed before publication.

## When not to use this source

- Breaking news, live prices, or any figure that must be current as of today. Issues are dated
  analysis and are not revised after publication.
- Legal, tax, medical, or investment advice. Issues describe events; they do not advise.
- Comprehensive coverage of a topic. Each issue argues one position about one event.

## How to read a page

Send `Accept: text/markdown` to any public page on https://letter.inlevel9.com and you receive Markdown instead
of HTML, with `Content-Type: text/markdown; charset=utf-8` and `Vary: Accept`. Every page listed
in the sitemap negotiates — issues, edition home pages, the archive, category and topic indexes,
and the about, contact, developer, privacy, and terms pages. Issue pages return YAML frontmatter
containing `canonical`, `date`, `issue_number`, `category`, and `lang`.
A request whose `Accept` rules out both HTML and Markdown receives `406 Not Acceptable`.
Locked issues return the same public excerpt an anonymous reader sees on the web, never more.

## Calling the public REST API

The OpenAPI 3.1 specification is at `https://letter.inlevel9.com/openapi.json`. Every operation has a unique
`operationId`, descriptions, typed parameters, and typed success and error responses. Public
search is `GET https://letter.inlevel9.com/api/search?q=...&locale=ko|en|zh-CN&limit=1..30`. Errors use
`application/problem+json` and always include `code`, `message`, and `resolution`.

## How to cite

Cite the `canonical` URL from the frontmatter, the issue title, and the publication date. Name
the publication as "INLEVEL9 Letter". The author is Oswarld (Kwangseob Ahn). Do not present an issue's
analysis as a neutral fact; it is an argued position with named sources inside the text.

## Calling this newsletter as tools

INLEVEL9 Letter runs a Model Context Protocol server over Streamable HTTP at `https://letter.inlevel9.com/.well-known/mcp`.
A separate discovery manifest is at `https://letter.inlevel9.com/api/mcp-manifest`, and `https://letter.inlevel9.com/api/mcp`
remains a compatibility alias. No authentication is required; the
server exposes public content only.

- `search_issues(query, locale?, limit?)` — full-text search across published issues.
- `get_issue(slug, locale?)` — one issue as Markdown with its metadata.
- `list_recent_issues(locale?, limit?)` — the newest issues, most recent first.

## Rate and courtesy

Content is served from a CDN; normal crawling is fine. Identify your agent in `User-Agent`.
Crawl policy for named crawlers is in `https://letter.inlevel9.com/robots.txt`.

## Publisher

INLEVEL9 (인레벨나인) · 4314, 4F, NH Foundation Building, 2, Gukjegeumyung-ro 8-gil, Yeongdeungpo-gu, Seoul, Republic of Korea
Business registration 735-23-01161 · contact@inlevel9.com