It is an agentic coding tool at its core, so yes - I'd say it's fair to call it a Claude Code alternative.
Regarding the GUI focus: we did that so it's more approachable to both tech folks and people not as accustomed to using a terminal (e.g. PMs, sales engineers, etc.). But a lot of our beta users are devs.
Also, when using its agentic search and data viz capabilities, some users prefer to not do that in the terminal.
Codex is OSS (and Aider of course) and serve as decent alternatives