# Trust Weighting UI/API Prep — PREP-POLICY-ENGINE-30-101-TRUST-WEIGHTING-UI-

Status: Draft (2025-11-20)
Owners: Policy Guild
Scope: Capture the UI/API surfaces for trust weighting once change events (30-003) are available.

## Dependencies
- Change events payload (30-003) and overlay schema (30-001).
- UI design tokens/UX from Console/Policy surfaces (not yet provided).

## Proposed API surface (draft)
- `GET /policy/trust-weighting` → returns current weights per source (`cartographer`, `concelier`, `scanner`, `advisory_ai`, etc.) and effective profile hash.
- `PUT /policy/trust-weighting` → accepts deterministic payload sorted by `source` with fields: `{source, weight, justification?, updated_at}`.
- `GET /policy/trust-weighting/preview?overlay_hash=` → previews recalculated statuses using supplied weights (calls simulation bridge under the hood).

## Determinism & validation
- Weights are decimals with fixed scale 3; sum not required to 1 but capped at max per policy profile.
- Payloads canonical JSON ordering; timestamps UTC.

## Acceptance to close PREP
- Align sources list with 30-003 change event fields and overlay inputs.
- Document schema at `docs/modules/policy/schemas/trust-weighting@draft.json` and sample at `docs/modules/policy/samples/trust-weighting@draft.json`.

## Handoff
Treat this as the prep artefact for PREP-POLICY-ENGINE-30-101-TRUST-WEIGHTING-UI-. Finalize once 30-003 is frozen and UI tokens arrive; then move implementation to DOING.