Diagrammatic proofs are ubiquitous in certain areas of mathematics, especially in category theory. Mechanising such proofs is a tedious task because proof assistants (such as Coq) are text based. We present a prototypical diagram editor to make this process easier, building upon the vscode extension coq-lsp for the Coq proof assistant and a web application available on the author’s personal website. It currently targets the UniMath mathematical library for the Coq proof assistant, but could in principle easily be adapted to other targets.