visibility-is-subset-check
IN premise
`_is_visible` requires ALL of a node's `access_tags` to be present in the caller's `visible_to` list (subset check, not intersection); nodes with no tags are always visible.
Summary
When checking whether a node can be seen, every single access tag on that node must appear in the caller's visibility list — having just some of them is not enough. This means visibility is strict: a caller only sees a node if they have clearance for all of its tags, and untagged nodes are visible to everyone by default.
Details
| Source | entries/2026/04/24/reasons_lib-api.md |