Using PlantUML ASCII with GitHub Copilot

This guide places the PlantUML ASCII skill from GitHub awesome-copilot in context. It is useful when diagrams must remain readable in a terminal, a pull request, or a plain-text message.

Preparation

First decide where the output will be consumed and whether the environment reliably supports UTF-8. Choose plain ASCII for maximum portability and the Unicode variant for clearer structure in modern terminals. Also check whether PlantUML is already available in the intended environment. The skill supplies agent guidance, but it does not replace local installation or verification of the selected tool version.

Designing the diagram

Describe the relevant roles, systems, transitions, and decisions to the agent. Short labels improve alignment. Ask for PlantUML source first and check that the start and end markers and the requested diagram type are appropriate. A local PlantUML execution can then produce a text file. Read the result using a fixed-width font and compare it with the intended technical meaning.

Reviewing and sharing

Inspect connections, arrow directions, labels, and line breaks. A visually tidy result can still express an incorrect relationship. Review output paths and file permissions before an agent performs follow-up processing. Share the diagram only after confirming that it remains readable in the destination channel. When a design becomes crowded, a smaller view or a graphical format may communicate more effectively.

Security boundaries

Treat diagram sources from tickets, web pages, or unfamiliar repositories as untrusted input. Do not permit automated follow-up processing without reviewing the content and destination path. Avoid placing credentials or confidential system details in a diagram that could be sent to an external model provider. According to the provider, the skill documents a workflow but does not take responsibility for your PlantUML version, agent permissions, or the confidentiality of input data.