What is Livery

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Livery is the software layer that lets a company's services talk to the web: it receives requests from browsers, mobile apps and other programs, hands them to the company's own code, and sends the answers back. This page explains what it does and why it matters, without code. Read it if you decide whether to use Livery, fund work on it, or run a team that builds on it.

The problem

Every online service needs a web layer. In the Erlang world, where many of the most reliable systems run (telephone switches, messaging services with hundreds of millions of users), building one today means putting together a dozen separate libraries: one for each version of the web's protocol, one for real-time updates, one for sign-in, one for monitoring, one for AI agents. Each comes with its own way of working, its own release schedule and its own gaps. The newest version of the protocol, HTTP/3, is missing or still experimental in the usual choices.

The result is more code to maintain, more people needed to maintain it, and features that other platforms take for granted arriving late.

What Livery does

Livery puts that layer in one package.

  • Every version of the web protocol, from the same code. A team writes its service once. Livery serves it over HTTP/1.1, HTTP/2 and HTTP/3 at the same time, and tells browsers that the newest one is available so they can switch to it.
  • Faster on mobile and poor networks. HTTP/3 connects in fewer round trips, and a lost packet slows down only the request it belongs to, not every request on the connection. Users on phones and weak connections feel the difference most.
  • Real-time features. Live updates, chat, notifications and streaming answers (such as text from an AI model, word by word) work the same way on every protocol.
  • Ready for AI agents. Livery speaks the Model Context Protocol (MCP) and Agent-to-Agent (A2A), the two common ways for AI assistants and agents to call a service. A company can open its tools to AI agents on the same server, with the same security, instead of running a second system for it.
  • Security included. Sign-in with an identity provider (OpenID Connect), passkeys, one-time codes, access tokens, client certificates and signed sessions are part of the package and follow the published standards. Each one is listed in the project with the standard it implements.
  • Visibility in production. Every request can be traced and measured with the OpenTelemetry conventions that common monitoring tools read.
  • Calling other services too. The same model works for the requests a service sends out, with timeouts, retries and load balancing in one place.

Why it matters

  • For a manager: one dependency instead of a dozen, one way of working for the whole team, and less code of your own to maintain. Features such as HTTP/3, passkeys or AI-agent access become settings, not projects.
  • For an investor: Erlang and its virtual machine (the BEAM) run systems that must not stop, and companies that choose them keep them for years. Livery gives that platform a modern web layer it was missing, including HTTP/3 and AI-agent protocols, under a permissive open-source license.
  • For the people who use the service: pages and apps that answer faster, especially on mobile, and sign-in methods such as passkeys that are both easier and safer than passwords.

Where it stands

  • Open source under the Apache 2.0 license, which allows commercial use. It is published on hex.pm, Erlang's package registry.
  • Young. The current version is 0.13. The design is settled and tested on every protocol, but the programming interface can still change between versions; each change is listed in the CHANGELOG.
  • Tested against itself. One test suite runs the same checks over every protocol and fails if any of them behaves differently.
  • Already used by companion libraries for gRPC, S3 storage and Stripe payments (see the Ecosystem).
  • The road to 1.0 is written down, with the status of each step, in "Toward 1.0", the last section of the design document.

Who is behind it

Livery is developed and maintained by Enki Multimedia. Companies that rely on it can reach out for support or sponsorship through the contact on the project page.

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