Introduction

This edition documents Tela v0.14.0-dev.3.

Tela is a connectivity fabric. It is a small set of programs that lets one machine reach a TCP service on another machine through an encrypted tunnel, without either side opening an inbound port, installing a virtual private network (VPN) client, loading a kernel driver, or running anything as root or Administrator. Remote desktop is the use case I built it for first. Remote desktop is just one application that runs on the fabric, not the point of it.

The point of the fabric is that the same three pieces scale from a single laptop reaching a single home server all the way up to a fleet of machines managed by a team, and the scaling does not require switching tools or rearchitecting anything. The pieces are an agent (telad) that runs on the machine you want to reach, a hub (telahubd) that brokers connections, and a client (tela) that runs on the machine you want to reach from. Each is a single static binary with no runtime dependencies. They run on Windows, Linux, and macOS.

The next chapter, What Tela is, covers the substrate properties, the design tradeoffs against existing tools, and the things Tela is explicitly not trying to be. It is the concept primer. After that, Installation and First connection get you to a working tunnel.

How this book is organized

Tela is the substrate. This book documents the substrate first and the features built on top of it second.

• The Getting Started section is a fast path from "I have never heard of Tela" to "I have a working tunnel."
• The User Guide section is the reference for the three binaries, the configuration files, and the desktop and portal clients.
• The How-to Guides section is a set of focused walkthroughs for the most common operational tasks.
• The Use Cases section walks through six concrete deployment scenarios with the access model and the deployment pattern for each.
• The Operations section covers the release process for hub and agent operators.
• The Design Rationale section answers the why questions: why three small daemons rather than one, why the hub is a blind relay, why remote administration works through the hub rather than directly, why file sharing has its own dedicated protocol, and why the gateway is a primitive that recurs at four layers. Read it after the body of the book if you want to understand the project's design decisions and the alternatives that were considered and rejected.
• The Appendices collect reference data: the CLI reference (A), the configuration file reference (B), the access model definition (C), the portal wire protocol (D), the Tela Design Language (E), and the glossary (F). Use them as lookups, not as reading.

The book tracks the stable release. It is updated as part of the stable promotion process, so the version shown at the top of this page matches the binaries on the stable channel.

Conventions

• The three binaries are tela (client), telad (agent or daemon), and telahubd (hub or relay).
• "TelaVisor" is the desktop graphical interface built on top of tela.
• A "group" is one hub and the agents connected to it -- the basic operational unit. A "fleet" is a collection of groups. The analogy is a carrier battle group (hub as carrier, agents as support vessels) within a fleet.
• A "hub directory" is anything that responds to the small Tela directory protocol; a "portal" is a directory plus extras (dashboard, identity, audit). See Hub directories and portals.
• Code, file paths, command-line flags, and configuration keys are in monospace.
• Mermaid diagrams render natively in the HTML output.

License

Apache License 2.0. See the LICENSE file in the repository.