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.
npx skills add 1llum1n4t1s/Retroweb-MCP --skill retrowebgit clone --depth 1 https://github.com/1llum1n4t1s/Retroweb-MCPWrote 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.
[](https://agentmods.dev/skills/1llum1n4t1s/retroweb-mcp/retroweb)<a href="https://agentmods.dev/skills/1llum1n4t1s/retroweb-mcp/retroweb"><img src="https://agentmods.dev/badge/skills/1llum1n4t1s/retroweb-mcp/retroweb/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.
<a href="https://agentmods.dev/skills/1llum1n4t1s/retroweb-mcp/retroweb"><img src="https://agentmods.dev/badge/skills/1llum1n4t1s/retroweb-mcp/retroweb.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00141 | $0.03535 |
| Opus 5 | $0.00071 | $0.01767 |
| Sonnet 5 | $0.00028 | $0.00707 |
| Haiku 4.5 | $0.00014 | $0.00353 |
Grade A, and why
retroweb 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.
How it starts
The opening of the file, as written. The whole thing — 198 lines — stays where its author put it; the contents beside it link to each section on GitHub.
レトロサイト発掘の手順
前提となる考え方
90 年代の個人サイトは 「検索」ではなく「ディレクトリとリンク集と Web リング」で発見される設計だった。 現代の検索エンジンを工夫しても届かないのは、索引が存在しないからで、クエリの問題ではない。
したがって取るべき戦略は 1 つ: 当時の発見経路をアーカイブ上で再生する。
これは日本語圏でも海外でも変わらない。違うのはホスト名・URL の階層・当時の言い回しの 3 点で、
海外にだけ全文検索の抜け道（wiby_search）がある。
Retroweb MCP のツールはこの経路をなぞる順に並んでいる。迷ったら retro_search_strategy を呼ぶ
（海外なら region="intl" を付ける）。
基本の流れ
1. 当たりを付ける（どのホストに居たか）
legacy_hosts で当時のホスティング一覧を得る。主題から置き場所を推測する。
region を指定しないと日本語圏と海外が混ざって返る（jp / intl / us uk fr de it nl au / global）。
日本語圏:
| 主題 | 見るべきホスト |
|---|---|
| 二次創作・CG・同人 | geocities.co.jp（エリア別）、isweb.infoseek.co.jp |
| テキスト・日記 | readme.jp、tesio.net（日記才人）、isweb |
| 技術・研究 | ac.jp/~user/、asahi-net.or.jp/~user/、bekkoame.ne.jp |
| 何でも | dir.yahoo.co.jp（人力ディレクトリ＝最大の名簿） |
海外:
| 主題 | 見るべきホスト |
|---|---|
| SF・ゲーム・オカルト | www.geocities.com/Area51（本家のエリア名は主題に対応している） |
| アート・音楽・映画 | www.geocities.com/SoHo /Hollywood /Vienna、www.angelfire.com |
| 技術・学術 | www.geocities.com/SiliconValley /Athens、edu/~user/、ac.uk/~user/ |
| 個人の日常・家族 | members.aol.com、hometown.aol.com、www.geocities.com/Heartland |
| 欧州語圏 | 英 homepages.demon.co.uk、独 home.t-online.de、仏 perso.wanadoo.fr / www.multimania.com、伊 digilander.iol.it |
| 何でも | dmoz.org（人力ディレクトリ＝海外最大の名簿）、dir.yahoo.com |
2. 個人サイトを直接列挙する ← 最も効く
discover_sites(url="www.geocities.co.jp/Playtown-Bingo", from="1998", to="2002")
これが主力。ホスティング配下に どんなサイトが実在したか をユーザー単位で一覧化する。
実測で 1 エリアから 148 サイトが出る。observedFiles が多いものほど中身が濃い。
エリア名が分からなければホスト名だけで呼んでよい。
discover_sites(url="www.geocities.co.jp", from="1997", to="2002")
索引全体へ散らして読むので、実在したエリア名が siteRoot に出てくる
（実測: 12 エリアにまたがる 226 サイトが 6 秒）。ただし結果は網羅ではなく標本で、
coverage.sampled が true になる。目当てのエリアが見えたら、そのエリアで呼び直すと深く掘れる。
ジオシティーズのエリア名は細分されている点に注意。Playtown だけでなく
Playtown-Bingo Playtown-Denen のようなハイフン付きが本体。
海外は URL の階層が違う。
discover_sites(url="www.geocities.com/SoHo", from="1997", to="2001") # 実測 163 サイト
discover_sites(url="www.angelfire.com", from="1999", to="2002")
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.
- 7d ago Changed · +15 lines 11f49e93d693
- 10d ago First seen · 183 lines · 141 tokens per session scan A 7a63cb1f7e13
retroweb is a skill published in the GitHub repository 1llum1n4t1s/Retroweb-MCP (0 stars, last pushed 4d ago), licensed MIT. It adds 141 tokens to every session and 3,535 once invoked, about $0.0007 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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