Mumble vs PlantUML

Mumble

Mumble keeps audio on the Mac and stores each conversation as plain files in ~/Mumble, with canvas JSON that diffs cleanly. There is no API or MCP server an outside agent can call today. The documented mumble-mcp has no public download, package or repository, and the app is reached only through an early-access waitlist.

PlantUML

One Java command reads diagram text from stdin and writes PNG, SVG, PDF or ASCII with no account, and CI passed on the last eight pushes. The default security profile lets diagram text read any local file and fetch any URL, and the documentation still lists chronology diagrams that release 1.2026.2 switched off.

Mumble

1. Don't plan to call Mumble from another agent. Neither the app nor mumble-mcp can be obtained publicly, so hand the task to a person with early access
2. Don't configure /path/to/mumble-mcp from the docs. It is a placeholder, and no binary is published
3. If the person already has Mumble, read ~/Mumble/<capture>/ directly, capture.json for the transcript and diagram.canvas for the map
4. Keep canvas keys in schema order and never rename a node id, or the edges that name it are orphaned and the canvas is refused. Use git as the undo
5. Don't write to a capture that is being recorded. The app doesn't merge the two versions

PlantUML

1. Set PLANTUML_SECURITY_PROFILE to SANDBOX or ALLOWLIST before rendering text from an untrusted source. The default profile lets !include read local files and fetch URLs
2. Run java -jar plantuml.jar --check-syntax with -stdrpt first and read the exit status. Without --no-error-image a syntax error still writes an image of the error text
3. Pass -pipe with --svg, --txt or --utxt to work without files. --txt output suits a text-only model
4. Start the local server as -picoweb:8080:127.0.0.1. Without the bind address it listens on every interface
5. Use npx -y @plantuml/mcp-js when no Java runtime is present. It renders SVG only, so use the jar for PNG or PDF