claude binary you run in your terminal, launched as a real subprocess in your repository, reading the same configuration it reads today.
That is the whole design. If you already have a Claude Code setup you trust, you keep it, and Fermata builds the factory around it.
What stays the same
The binary. Fermata checks a path you configured first, then yourPATH, then the usual install locations: ~/.local/bin, /usr/local/bin, /opt/homebrew/bin, and a few more. Nothing is vendored or bundled.
Your login and your billing. Fermata does not hold an account of its own. The CLI authenticates as it does today. Anthropic meters what the agents use.
Your project instructions. Agents run with the repository as their working directory, so the CLAUDE.md files the CLI would read there are the ones it reads here. Fermata can add standing per-project context on top of them; see project instructions.
Your slash commands and skills. Typing / in a prompt field opens a palette of the commands and skills from your project directory, your user directory, and any plugins enabled for that project. The command is forwarded to the CLI as plain text, so it behaves exactly as it does in the terminal.
Your MCP servers, subagents, and settings. The CLI reads its own configuration directory the way it always does, and Fermata passes your environment through to each subprocess rather than rebuilding it. If you keep more than one Claude configuration directory, you can say which one a project’s sessions use, globally or per project, in Settings.
The conversation. A session is a live CLI process, not a transcript viewer. Send follow-ups, interrupt, attach files, redirect. It behaves like the CLI session it is, because that is what it is.