TYPO3 Dev Companion

Experimental. This is a 0.x package and its surface is not settled. The package name, the binary, the namespace and the environment variables all changed in one cut on 2026-08-06. The tool names and the shapes they answer in can move the same way. Pin a commit where you depend on it.

A local MCP server (plain PHP) that helps coding agents implement, review and verify TYPO3 work for the three audiences that do it: the core contributor, the extension author and the site developer. It establishes the project and installation the agent is working in, supplies current, version-bound TYPO3 knowledge, and hands task-specific workflows to the skills that own them.

It answers for TYPO3 12.4, 13.4, 14.3 and main. A statement that does not hold on all of them names the ones it does, so an LTS is never handed a convention that only the development line has.

The MCP client launches it as a subprocess over stdio, so there is no server to host, no network exposure and no auth to configure — the process boundary is the trust boundary. It reads: nothing is written into the TYPO3 installation it is pointed at, and nothing on the machine is started as a side effect of a lookup.

Quickstart

Requirements: PHP 8.2+ and Composer. The package works both ways — as a standalone checkout and as a Composer dependency of another project.

# standalone: clone, install once, then point a project at it
composer install
/absolute/path/to/typo3-dev-companion/bin/typo3-dev-companion install

# as a dependency: from the consuming project's root
vendor/bin/typo3-dev-companion install

install writes the typo3-dev-companion entry into the project's .mcp.json and publishes the task skills to .agents/skills — the two locations a client finds without being configured for it. --agent=<id> writes them where that client actually reads them instead.

It is also the only supported way to get the skills: a copy of skills/ taken out of this repository by hand is missing the references/base.md the installer writes into each of them, and every skill opens on that file.

Documentation

The manual reads as a site at typo3.github.io/dev-companion, and as files in documentation/:

• Usage — every client and layout the install supports, the task workflows it publishes, and what you are agreeing to when it runs.
• Server — what it can be asked, one page per tool, and where each answer comes from.
• Contributing — working on this repository rather than using it.
• Records — how feedback from a real session becomes an improvement.

The conventions every session here works under are AGENTS.md.