你所有代码代理仓库的地图。 Cairn 会扫描文件夹里的每个 git 仓库一次，能用 了解它们如何连接，并为你的代理人提供：

• 一个极小且始终加载的索引;
• 每个仓库一张短卡。

代理人知道物品所在位置，无需重新探索。

石堆是堆叠的石碑，引导徒步者沿着小径前行。石堆留下的小而廉价的遗迹 标记引导编码代理找到正确的仓库，然后再到正确的文件。

支持Claude Code、Codex、Gemini CLI和Cursor，支持Windows、macOS和Linux。 使用 Claude 代码？安装 cairn 作为插件，或者粘贴那部分 然后它会帮你安装所有东西。

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为什么

编码代理在一个仓库中工作。实际工作涵盖多个仓库：网页应用、API、共享类型 包裹、支付服务、报告工作。写*“在出行的端到端增加小费金额”*，然后 代理人必须：

1. 发现存在兄弟仓库;
2. 通过所有 grep;
3. 阅读一堆文件;
4. 猜测哪个服务拥有trips表。

这会消耗代币和回合，较弱的模型也会猜错。

手工维护的“相关仓库”文档能帮忙，直到它们变得陈旧。Cairn 是根据代码构建那个映射的 保持新鲜感：

cairn

A map of all your repos for coding agents. cairn scans every git repo in a folder once, works out how they connect, and gives your agent:

• a tiny always-loaded index;
• a short card per repo.

The agent knows where things live without re-exploring.

Cairns are the stacked-stone markers that guide hikers along a trail. cairn leaves small, cheap markers that guide coding agents to the right repo, and then to the right file.

Works with Claude Code, Codex, Gemini CLI, and Cursor, on Windows, macOS, and Linux. Using Claude Code? Install cairn as a plugin, or paste that section into Claude Code and it installs everything for you.

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Why

Coding agents work inside one repo. Real work spans many: a web app, an API, a shared types package, a payments service, a reporting job. Say “add a tip amount to trips end to end” and the agent has to:

1. discover that sibling repos exist;
2. grep through all of them;
3. read a pile of files;
4. guess which service owns the trips table.

That costs tokens and turns, and weaker models guess wrong.

Hand-maintained “related repos” docs help until they go stale. cairn builds that map from the code itself and keeps it fresh:

~/code/                          ~/code/.cairn/
├── rider-web/        cairn      ├── INDEX.md           ← ~25 tokens per repo, always loaded
├── trips-svc/        ─────▶     ├── cards/trips-svc.md ← read on demand (≤ 800 tokens)
├── payments-svc/     scan       ├── workspace.json     ← the full graph
├── analytics-etl/               └── authored/          ← your summaries and decisions
└── …

What your agent sees

The index is a few lines, loaded into every session through CLAUDE.md or an equivalent:

# Workspace repos (cairn)
- admin-console (@fleetline/admin-console): Next.js back-office for ops staff; queries trips… · nextjs
- analytics-etl: Nightly SQL reporting jobs over trips, payments, drivers… · python
- payments-svc (payments): Go service that charges completed trips and records weekly payouts · go
- trips-svc: FastAPI service owning the trip lifecycle and the trips/trip_events tables · fastapi · used by admin-console
- ui-kit (@fleetline/ui-kit): Shared React components (Button, Card) · react · used by admin-console