# Batch Context Endpoint Prep — PREP-POLICY-ENGINE-31-002-BATCH-CONTEXT-ENDPO

Status: Draft (2025-11-20)
Owners: Policy Guild
Scope: Define the batch context endpoint contract that builds on Advisory AI knobs (31-001) and trust weighting outputs.

## Dependencies
- Final knobs list from 31-001.
- Policy profile schema (hash + version) from 30-001 overlays.

## Draft API surface
- `POST /policy/batch/context` with payload: `{tenant_id, policy_profile_hash, knobs_version, overlay_hash, items:[{component_purl, advisory_id}], options:{include_reachability:boolean}}`.
- Response: `{context_id, expires_at, knobs_version, overlay_hash, items:[{component_purl, advisory_id, status, trace_ref}]}`.
- Determinism: items sorted by `(component_purl, advisory_id)`; `context_id` derived as hash of request payload.

## Acceptance to close PREP
- Align fields with 31-001 knobs and 30-001 overlay schema; record hashes/versions.
- Save draft schema at `docs/modules/policy/schemas/policy-batch-context@draft.json` and sample at `docs/modules/policy/samples/policy-batch-context@draft.json`.

## Handoff
Use this document as the prep artefact for PREP-POLICY-ENGINE-31-002-BATCH-CONTEXT-ENDPO. Update when knobs and overlays freeze; then move implementation to DOING.