# Policy Engine Contracts

> **Contracts only.** No policy evaluation engine in this wave.  
> Targets: [policy-targets.md](policy-targets.md)  
> Contract version: `policy-engine.v1`  
> ADR: [ADR-023](../architecture/adr/ADR-023.md) (v1.2)

---

## 1. Purpose

**Policies** are independent commercial/governance rules that may constrain eligibility, licensing, pricing application, activation, visibility, quotas, marketplace behavior, compliance, and related concerns.

Policies are **not** products, bundles, assets, or capabilities. They attach by reference.

---

## 2. PolicyDefinition

| Field | Type | Meaning |
| --- | --- | --- |
| `registry_object_id` | uuid | Universal ID |
| `policy_code` | string | Stable open code |
| `policy_kind` | string | Open kind — see §3 |
| `display_name` | string | |
| `status` | enum | `draft` \| `active` \| `deprecated` \| `retired` |
| `version_code` | string | |
| `priority` | int | Higher wins on conflict (future engine) |
| `effect` | enum | `allow` \| `deny` \| `require` \| `transform` \| `inform` |
| `targets[]` | PolicyTargetBinding | See [policy-targets.md](policy-targets.md) |
| `conditions` | object | Open predicate bag (unevaluated here) |
| `parameters` | object | Open parameters |
| `metadata_ref` | uuid? | |
| `documentation_ref` | string? | |
| `ext` | object | |

---

## 3. Policy kinds (examples — open registry)

| policy_kind | Meaning |
| --- | --- |
| `eligibility` | Who may acquire/activate |
| `licensing` | License grant constraints |
| `commercial` | General commercial rules |
| `regional` | Country/region gates |
| `pricing` | Which pricing items apply |
| `tax` | Tax class / inclusivity hints |
| `promotion` | Promotional windows |
| `discount` | Discount class application |
| `activation` | Activation pipeline constraints |
| `feature_visibility` | UI/API surface visibility |
| `capability_access` | Capability enable rules |
| `quota` | Quota ceilings |
| `marketplace_rules` | Marketplace listing/commerce rules |
| `compliance` | Regulatory/compliance |
| `security` | Security posture rules |
| `support` | Support tier rules |
| `trial` | Trial eligibility/duration |
| `renewal` | Renewal behavior |
| `expiration` | Expiry / sunset |

Unlimited future `policy_kind` values MAY be registered without architecture changes.

---

## 4. Policy evaluation (future — documented only)

Logical interface (not implemented):

```
EvaluatePolicies(context) → { decisions[], deny_reasons[], transforms[] }
```

Context MAY include tenant, workspace, product, bundle, subscription, license, region, industry, asset, metadata snapshots.

---

## 5. Invariants

1. Policies never write foreign service databases directly — they inform Core commercial / activation decisions.
2. Payment L2/L3 remain owned by Payment; policies may *gate* L1 or commercial packaging only.
3. Tax/discount/promotion engines are **not** authorized by these contracts alone.
4. No ownership transfer to Marketplace or Experience via policy kinds.