# Authority Boundary

> A written statement of which facts this repository owns and which are owned elsewhere, so citation never becomes silent forking.

**Tier:** 0 · **Normative weight:** implements `TM-MOD-005`; supports
`TM-CUR-008`, `TM-CUR-009`
**Requires:** nothing

## Problem it removes

Two repositories each half-own a fact — a deployment target, a design
token, a customer detail — and drift apart, with neither able to say which
copy is authoritative. Observation quietly becomes a fork: a value copied
in for convenience starts evolving independently of its owner.

## Mechanism

A short section, usually in the
[Front Door](/docs/truth-machine/kit/front-door/), stating in plain
sentences the declared ownership split `TM-MOD-005` requires: the facts
this repository owns; the facts it observes but
that named sibling systems own ("`cloud-ops` owns production appointment
and rollback"); and the material that must never enter (credentials,
customer data, raw logs). Owned-elsewhere facts are cited or observed at an
exact revision, never copied and maintained (`TM-CUR-008`). When ownership
of a fact moves between repositories, the move is recorded as an explicit
handoff naming the receiver and the boundary (`TM-CUR-009`), and the
predecessor stops evolving its account.

## Cost

Authoring: the hard part is deciding, not writing — an hour of ownership
questions. Per change: only at real ownership changes, each of which
deserves a recorded handoff anyway. Per session: none.

## Do not adopt when

The repository is genuinely self-contained — it observes nothing owned
elsewhere and nothing observes it.

## Evidence

Assessed in [cloud-ops](/docs/truth-machine/implementations/cloud-ops/) and
[inference-ops](/docs/truth-machine/implementations/inference-ops/), whose
ownership seams are mechanically checked across repositories. Observed in
kinra-os.

## Template

None — adopted by convention, as a section of the front door.

## Related patterns

[Declared Versus Observed](/docs/truth-machine/kit/declared-versus-observed/)
is how an owned-elsewhere fact is watched without being forked.