Lumen Protocol v0, revision 25 (frozen snapshot). © Moonbase 2090 LLC. Licensed under CC-BY-4.0. Report security issues privately via GitHub private vulnerability reporting or [email protected].

Capability negotiation and versioning

Versions

The protocol version is major.minor. A minor version adds optional features. A major version may break compatibility.

Capabilities

v0 defines the capabilities images, tables, rgb-color, cell-spans, side-channel, hyperlinks, clipboard-write and notifications. The notifications grant is the one that lets a sealed frame draw a terminal toast, or an OS notification when the user has enabled it (Notifications). An advertisement (including LUMEN=0) is only a hint. The terminal decides by its policy, and nothing is ever granted because of the advertisement alone.

Grants

Capabilities are granted per sealed layer, at shell start, by local policy and chrome prompts. The default grant for a remote layer is text, tables and links.

Clipboard write

clipboard-write requires a confirmation drawn by the terminal that shows the exact bytes. The confirmation covers one write or the layer. Track 0 can never write the clipboard. See Clipboard.

Policy file

Policy is read only from a user-owned file whose mode does not allow writes by group or others. It is never read from the current directory, the environment, frames or a remote host. A file that fails these checks is ignored, with a chrome notice, and the defaults apply. A system-wide file MAY exist only for the settings that this specification allows it to set (for example hardened mode).