⛰ Desktop app · Windows & macOS

The environment & connection manager for small dev teams

Cairn keeps every URL, server, connection string, and SSH target for your dev, staging, and prod environments in one structured desktop app — so a new hire is productive in hours, not days. Secrets stay in the manager you already trust; Cairn only holds the reference.

Buy a license — $19 Download free

Free for 2 projects, no card · $19 one-time for unlimited · up to 3 machines · 1 year of free updates. Your environment data lives in plain project.json files you own — no account, no cloud sync.

🔒 No secrets at rest — references only 🖥 Native Windows & macOS 📴 No account — your data stays local 🧩 MCP server built in for AI tools (licensed) 📄 Plain JSON you can diff & back up

One source of truth for every environment you run

Stop scavenger-hunting for environment info. The details scattered across READMEs, wikis, Slack threads, and three people's laptops — gathered into one app your whole team can read.

🗂

Single source of truth

Environments, servers, URLs, databases, and runbook notes in one tree per project — dev, staging, prod side by side.

🔐

Secrets by reference — 1Password, Bitwarden, Keychain

Cairn never stores a secret value. It holds a secret link into your vault — 1Password, Bitwarden, Windows Credential Manager, or macOS Keychain — resolved only at launch.

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One-click connect

Hit Connect on any node to open a URL, SSH into a server, or run a command — the right key, user, and host wired in for you.

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Onboard in hours

Hand a new hire the project file: every environment, host and link is there on day one — no week of pinging the team.

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Share a single file

A project is one project.json. Send it, back it up, diff it in git — no server, no sync account, no lock-in.

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Built-in MCP server for Claude and other AI tools

A built-in loopback MCP server lets Claude and other tools read and edit your projects through a safe, local API. Included with a license.

How Cairn works — from install to a connected terminal

From install to a connected terminal in four steps.

1

Create a project

One project per product or client. Add your environments and tiers.

2

Add resources

URLs, servers, databases, and commands — nested into groups any depth you like.

3

Link secrets

Point each credential at your external manager. Nothing sensitive is written to disk.

4

Connect

Hit Connect to open, SSH, or run. Share the file so the team has the same map.

Your data lives in project.json on your machine and stores no secret material, ever — the Free tier never goes online, and only activating a paid license needs a one-time online check.

Pricing — $19 one-time, per developer

Simple, honest pricing. Buy through Paddle — taxes and receipts handled for you, anywhere in the world.

Free
$0
2 projects · 2 environments each
  • Secret links & one-click connect
  • Windows & macOS builds
  • No account, no card
  • Works fully offline
Download

Need team or volume licensing? Get in touch — VAT/sales tax is handled by Paddle as Merchant of Record.

Cairn FAQ — secrets, platforms, licensing and MCP

Still unsure? Ask support — we answer fast.

Does Cairn store my passwords or secrets?
No. Cairn stores environment metadata only — never a secret value. Each credential is a secret link (a locator) into an external manager — 1Password, Bitwarden, Windows Credential Manager, or macOS Keychain — resolved at launch and never written to disk. Sharing a project file leaks no secrets.
Which platforms are supported?
Windows 10 and Windows 11, plus macOS 13 Ventura and newer on Apple Silicon (M1 and later). No Intel Mac, Linux desktop, or mobile build yet.
How does licensing work?
Cairn is free for up to 2 projects with 2 environments each — no key, account or card. A license is a one-time purchase, per developer: it removes those limits and adds the built-in MCP server. After checkout you'll get a license key by email that unlocks the app on up to 3 of your machines — deactivate one to free a seat and move it to another. Your purchase includes 1 year of free updates, and the app keeps working afterward.
Can I use it offline?
Day-to-day, yes — your data is plain project.json files on your own machine, with no account and no cloud sync, so normal use needs no network. The Free tier never goes online. The one exception is activating a purchased key, which needs a quick one-time online check. After activation the app keeps working offline (it only re-verifies your license periodically in the background).
What is the built-in MCP server?
A loopback-only (127.0.0.1) Model Context Protocol server that lets AI tools such as Claude read and edit your projects through a safe local API. It's off by default and you control the port — nothing is exposed to the network. The MCP server requires a paid license.
How do I get support or request a feature?
Support tickets go through our help portal. Feature ideas and roadmap voting live on our public feedback board.

Give your team one map for every environment.

Download Cairn free, or buy a license and stop the onboarding scavenger hunt today.

Buy a license — $19 Download free

Download Cairn for Windows and macOS

Free for 2 projects — no account, no card. A license removes the limits.

Direct download (MSI) — for managed or offline machines, or to update an existing MSI install