# Underpass documentation

> Underpass connects laptops, servers and cloud machines into one private, encrypted network (WireGuard). Devices reach each other directly, through NATs and firewalls, with an encrypted relay as a fallback. This file lists every documentation page; each link is the page's Markdown.

Full documentation in one file: https://docs.getunderpass.com/llms-full.txt

## Getting started

- [Quickstart](https://docs.getunderpass.com/md/getting-started/quickstart.md): Create an account and connect your first two devices in a few minutes.
- [Install](https://docs.getunderpass.com/md/getting-started/install.md): Install the app on Windows, macOS and Linux, and remove it again.
- [Add a server](https://docs.getunderpass.com/md/getting-started/add-a-server.md): Join servers, cloud VMs and other headless machines, with a sign-in link or with an auth key from a script.

## Concepts

- [How it works](https://docs.getunderpass.com/md/concepts/how-it-works.md): The coordination service, direct connections between devices, and the relay that steps in when a direct path isn't possible.
- [Security](https://docs.getunderpass.com/md/concepts/security.md): Encryption and keys, what each part of the system can and can't see, and the controls you have.

## Features

- [Easy names](https://docs.getunderpass.com/md/features/easy-names.md): Reach every device and service by name instead of its address, and keep using your own DNS for everything else.
- [Services](https://docs.getunderpass.com/md/features/services.md): Give an internal app one name and address, run it on several machines, and let devices move to a backup on their own.
- [Subnet routes](https://docs.getunderpass.com/md/features/subnet-routes.md): Reach a whole network, like an office LAN or a cloud VPC, through one machine, without installing the app on every device in it.
- [Exit nodes](https://docs.getunderpass.com/md/features/exit-nodes.md): Send a device's internet traffic out through another machine in your network, like a server you trust or a machine at home.
- [App connectors](https://docs.getunderpass.com/md/features/app-connectors.md): Send traffic for chosen internet domains out through one machine, so services with an IP allow-list only need one address.
- [Access controls](https://docs.getunderpass.com/md/features/access-controls.md): Decide which people and devices can reach each other, with rules by group, tag, service or app, and tests that run before you save.
- [HTTPS certificates](https://docs.getunderpass.com/md/features/https.md): Get trusted HTTPS certificates for your machines' names, renewed automatically, with no browser warnings.

## Manage

- [Machines](https://docs.getunderpass.com/md/manage/machines.md): See, approve, rename, share and remove the devices in your network, and control how long they stay signed in.
- [People and roles](https://docs.getunderpass.com/md/manage/people.md): Invite your team by email or link, approve who joins, give each person a role, and switch between workspaces.
- [Auth keys](https://docs.getunderpass.com/md/manage/auth-keys.md): Keys that let machines join your network without a browser, for servers, scripts, containers and CI.
- [Two-factor sign-in](https://docs.getunderpass.com/md/manage/two-factor.md): Protect your account with an authenticator app, and require it for everyone in a workspace.
- [Logs and webhooks](https://docs.getunderpass.com/md/manage/logs.md): The tamper-evident audit log, network logs, webhooks for events, and streaming logs to your own tools.
- [API](https://docs.getunderpass.com/md/manage/api.md): Automate your workspace with the REST API and API tokens, or connect an AI agent through the MCP server.
- [Plans and billing](https://docs.getunderpass.com/md/manage/plans.md): What each plan includes, how device limits are counted, and what happens at a limit.

## Reference

- [CLI reference](https://docs.getunderpass.com/md/reference/cli.md): Every command and flag of the command-line tool, with what it prints.
- [Limits](https://docs.getunderpass.com/md/reference/limits.md): Every number you might run into, in one place.
- [Troubleshooting](https://docs.getunderpass.com/md/reference/troubleshooting.md): Fix the most common connection and setup problems, by the message you see.
- [Glossary](https://docs.getunderpass.com/md/reference/glossary.md): The words used across the product and these docs.