scema-tools

Perception, and workspace confinement.

Part of Scematica Omni — an agent runtime that perceives an environment, projects competing futures, ranks them under a stated preference, decides or refuses to, and seals a verifiable record of what it did.

The organising idea across every crate: each layer can say "I don't know", and saying it costs nothing. An agent that cannot express ignorance expresses a number of the right shape instead, and nothing downstream can tell it from a measurement.

The only crate in the read path allowed to touch the outside world. Observer is the interface; RepoObserver walks a source tree and counts what can be counted.

Three obligations on every observer:

1. Report what could not be read — into blind_spots, which becomes measured uncertainty downstream. Ignorance the observer knows about is the most useful thing it can pass up.
2. Never round an unread thing to zero. An unreadable unit is Provenance::Absent with no attributes, not a unit with zeroes.
3. Say whether the walk was complete — Extent { total: None } when a cap was hit.

A deliberate exclusion is not a blind spot: skipping target/ is a decision, not a failure, and filing it as ignorance buries the paths that really could not be read.

Workspace also lives here, and answers where only — resolve fully (symlinks followed, .. collapsed) then compare against roots, because a string scan for .. passes a symlink pointing at /. Used by the daemon and the MCP server, whose callers are a browser extension and a language model.

Licensed MIT.