--- title: "Upgrading Legacy BuildMaster Agents to The Inedo Agent" nav-title: "Legacy BuildMaster Agents" order: 2 url-slug: "buildmaster/installation-maintenance/buildmaster-legacy/buildmaster-legacy-features/buildmaster-upgrading-to-v5-agent-comparison" ---

In BuildMaster 5.0, we introduced the Inedo Agent as a replacement for what we now call Legacy BuildMaster Agents.

Legacy BuildMaster Agents are only available until BuildMaster 6.1, which means you won't be able to upgrade to newer versions until you remove them all from your instance.

## What is the Inedo Agent?

Our products (BuildMaster and Otter) automate and orchestrate your infrastructure by deploying files and sending commands to your servers. BuildMaster and Otter can communicate with servers through common channels such as WMI (Windows) and SSH (Linux) or through a simpler and more specialized protocol, Inedo Agent.

Unlike the Legacy BuildMaster Agents, Inedo Agents do not need to be updated every time the product is upgraded. Because they are backward and forward compatible, upgrading the agent is usually optional; if an upgrade is available or required, the release notes and software will indicate the upgrade.

Because upgrading an agent involves some risk (essentially, the agent must overwrite itself and then restart), both BuildMaster and Otter have a utility that upgrades these agents on a large scale.

## Migrating from Legacy BuildMaster Agents

In BuildMaster 5.0 and earlier, a different agent model was used. We recommend using the Inedo Agent for new installations/servers and gradually switching to the Legacy Agent as time permits to test deployments on those servers. Support for BuildMaster Legacy Agent support was removed in BuildMaster 6.2.

Agents can be converted from a Legacy to an Inedo Agent by navigating to the server page and then edit > convert. This will display the following dialog:

## Legacy BuildMaster Agent Types

### Self-Hosted Agent

This agent uses a lightweight, binary TCP-based protocol that provides all the features of the SOAP-hosted agent, but with much less overhead. It is currently only available on Windows as an installable service.

### SOAP-Hosted Agent

This agent is a simple SOAP-based web service that can be installed on a Windows (or Linux with Mono) based server. It provides all the features of a Local Agent, is relatively easy to set up, and can be hosted with IIS to provide a wide range of security/access options. However, the SOAP protocol can add significant overhead, which can be a problem for very large deployments.