Structured content for the terminal.
Lumen is an open protocol for blocks, text runs, layout and events. Rich blocks get proportional type and browser-style layout; grid blocks host legacy terminal apps, so old and new share one document.
Rich blocks
Proportional fonts, wrapping and layout, described as structured data rather than escape codes.
Grid blocks
A cell grid on its own PTY, sized to the block, so existing terminal apps keep working inside a Lumen document.
Security first
The prime directive: capabilities are explicit, content is inert by default, disclosure is private.
Not backwards compatible, by design
Lumen is a new protocol rather than another escape-code extension. Grid blocks give existing terminal apps a native place inside a Lumen document, and unverified output is always shown as plain, inert text.
Status
The current public draft is Lumen Protocol v0, revision 25 (frozen snapshot). It is not stable, and breaking changes are expected. Read the spec.