Instant previews for data, config, and diagram files

July 8, 2026

A whole family of file types now gets the same 3-mode preview (Editor / Split / Preview) as Markdown, turning raw data and config into something readable. All on by default.

Structured data. .json, .yaml, and .toml render a collapsible, type-colored data tree, and .xml renders a faithful DOM tree. A JSON or YAML file recognized as an OpenAPI 3 / Swagger 2 spec instead becomes browsable API docs, with a tree ⇄ docs toggle.

Config, decoded to plain English. A crontab turns 30 2 * * 1-5 into “At 02:30, Monday through Friday” and lists the next fire times. fstab, systemd units (with OnCalendar= next triggers), SSH config (a one-line connection summary per host), Dockerfile (a per-stage digest), and GitHub Actions workflows all get the same treatment, with malformed lines flagged.

Diagrams as code. Standalone Graphviz DOT (.dot/.gv) and PlantUML (.puml) files preview via the dot / plantuml CLIs, with export to SVG / PNG / PDF.

Viewers. .pdf files open in a read-only page viewer, and .svg files stay editable XML but gain a live rendered-image preview. Every preview exports to PDF from its right-click menu. See the previews guide and diagrams.