diff --git a/adapters/README.md b/adapters/README.md
index 17900eb..6862b8f 100644
--- a/adapters/README.md
+++ b/adapters/README.md
@@ -12,6 +12,37 @@ Adapters translate the engine-agnostic Target Stack IR to engine-specific format
 | Checkov adapter | `adapters/terraform/policy/checkov_adapter.py` | Checkov JSON | `PolicyCheckResult` records | Translates Checkov results |
 | Wiz adapter | `adapters/wiz/wiz_adapter.py` | Wiz API issues JSON | `PolicyCheckResult` records | Translates Wiz security findings |
 | Kyverno adapter | `adapters/kyverno/kyverno_adapter.py` | Kyverno PolicyReport JSON | `PolicyCheckResult` records | K8s-native policy translation |
+| kyverno-json engine | `adapters/kyverno-json/kyverno_json_engine.py` | Any JSON/YAML payload | `PolicyCheckResult` records | **v1.25 primary policy engine** (swappable via `PolicyEngine` protocol) |
+
+## Policy Engine Protocol (v1.25)
+
+The `core/policy_engine.py` module defines the **swap boundary** between
+Nova and its policy engines. A `PolicyEngine` Python Protocol (PEP 544)
+with three members (`name`, `is_configured()`, `evaluate()`) is the
+contract; a `PolicyEngineRegistry` selects the active engine from
+`config.json`'s `policy.engine` key. The confidence signal and pipeline
+never import an engine directly — they go through the registry.
+
+**Implementations:**
+- `KyvernoJsonEngine` (`adapters/kyverno-json/`) — shells to the `kj`
+  CLI; the v1.25 default.
+- `NullEngine` (`core/policy_engine.py`) — fallback when the `policy`
+  key is absent (emits `SKIPPED`).
+- Future: `OpaEngine` — implements the same protocol, shells to
+  `opa eval`. The OPA-equivalent surface is documented in
+  `.ciagent/RESEARCH.md` §4.2.
+
+**How to add a new engine:**
+1. Create `adapters/<name>/<name>_engine.py` implementing the
+   `PolicyEngine` protocol (`name`, `is_configured()`, `evaluate()`).
+2. `evaluate()` returns `list[dict]` where each dict conforms to
+   `schemas/policy_check_result.schema.json`.
+3. Register the engine in `core/policy_engine.py`'s `_autoload_*`
+   function (or call `register(name, factory)` at startup).
+4. Set `config.json.policy.engine` to the engine's `name`.
+5. Add the engine to the `engine` enum in
+   `schemas/policy_check_result.schema.json` if it needs a distinct
+   enum value (v1.25 reuses `"kyverno"` — see D-116).
 
 ## How to Write an Adapter
 
diff --git a/adapters/kyverno-json/README.md b/adapters/kyverno-json/README.md
new file mode 100644
index 0000000..fd156d1
--- /dev/null
+++ b/adapters/kyverno-json/README.md
@@ -0,0 +1,103 @@
+# kyverno-json Engine Adapter (v1.25)
+
+The `kyverno-json` engine is Nova's **primary compliance/policy tool**
+(v1.25), implemented behind the swappable `PolicyEngine` protocol so
+OPA (or any other engine) can replace it one day.
+
+## What kyverno-json is
+
+[kyverno-json](https://github.com/kyverno/kyverno-json) is a standalone
+Go binary from the Kyverno project — a **separate runtime** from the
+K8s Kyverno admission controller. It applies Kyverno `ValidatingPolicy`
+resources to **any** JSON or YAML payload file via the `kj scan` CLI.
+Unlike the K8s Kyverno adapter (`adapters/kyverno/`), which only
+speaks to K8s manifests, kyverno-json evaluates consumer contracts,
+resolved Stack IR, terraform plan JSON, and even the merged PCR list
+itself (meta-policies).
+
+## Install
+
+```bash
+bash scripts/install-kyverno-json.sh
+# or directly:
+go install github.com/kyverno/kyverno-json/cmd/kj@latest
+kj version
+```
+
+The platform functions without the binary — `is_configured()` returns
+`False` when `which kj` is absent → `evaluate()` returns a single
+`SKIPPED` PCR (`KJ_ENGINE_NOT_CONFIGURED`). The confidence signal
+proceeds with a neutral `policy` input (D-120 graceful degradation).
+
+## Policy directory layout
+
+```
+adapters/kyverno-json/policies/
+├── _smoke.json                  # round-trip smoke test
+├── contract/                    # consumer contract JSON policies
+│   ├── require-id-pattern.json
+│   ├── require-env-in-enum.json
+│   ├── require-infrastructure-min-1.json
+│   └── forbid-unknown-fields.json
+├── stack-ir/                    # resolved Stack IR policies
+│   ├── require-tagging-standard.json
+│   ├── forbid-public-ingress.json
+│   └── require-encryption-by-default.json
+├── plan-json/                   # terraform show -json policies
+│   ├── forbid-plaintext-secrets.json
+│   ├── forbid-iam-wildcard.json
+│   └── require-kms-reference.json
+├── meta/                        # policies over the merged PCR list
+│   ├── block-on-any-critical.json
+│   └── tagging-rules-agree.json
+└── regression/                   # capability-inventory policies
+    ├── cap-013-adapter-dedup.json
+    ├── cap-023-metrics-collector.json
+    └── cap-024-deck-structure.json
+```
+
+## The four policy categories
+
+1. **contract/** — over the consumer contract JSON (pre-resolve).
+2. **stack-ir/** — over the resolved Target Stack IR (post-resolve).
+3. **plan-json/** — over `terraform show -json` output (pipeline Step 5b).
+4. **meta/** — over the merged `list[PolicyCheckResult]` (meta-policies).
+5. **regression/** — over the capability-inventory JSON (declarative
+   mirrors of `core/regression_verify.py`).
+
+## Severity convention
+
+kyverno-json does not natively assign severities. Each Nova policy
+declares its severity via a `metadata.annotations` field:
+
+```yaml
+metadata:
+  annotations:
+    nova.cloudinit.dev/severity: high
+```
+
+Valid values: `critical`, `high`, `medium`, `low`, `info` (default
+when absent).
+
+## Engine enum reuse (D-116)
+
+kyverno-json PCR records carry `engine: "kyverno"` (no new enum value).
+The `engine` field records the policy-engine *family*, not the specific
+binary. The K8s Kyverno adapter and the kyverno-json engine are
+distinguished by `ruleId` prefix (`KYVERNO_` vs `KJ_`) and `evidence`
+payload shape (`namespace`/`kind` vs `assertion`/`jmespath`).
+
+## Schema path
+
+The output records validate against
+[`schemas/policy_check_result.schema.json`](../../schemas/policy_check_result.schema.json)
+(`engine: "kyverno"` is in the enum). The confidence signal consumes
+the merged PCR list engine-agnostically.
+
+## Swap boundary
+
+The `PolicyEngine` protocol (`core/policy_engine.py`) is the swap
+boundary. The OPA-equivalent surface is documented in
+`.ciagent/RESEARCH.md` §4.2 — a future `OpaEngine` implements the same
+protocol without touching the confidence signal, the PCR schema, or
+the pipeline.
\ No newline at end of file
diff --git a/adapters/kyverno-json/policies/regression/cap-013-adapter-dedup.json b/adapters/kyverno-json/policies/regression/cap-013-adapter-dedup.json
new file mode 100644
index 0000000..1701640
--- /dev/null
+++ b/adapters/kyverno-json/policies/regression/cap-013-adapter-dedup.json
@@ -0,0 +1,30 @@
+{
+  "apiVersion": "json.kyverno.io/v1alpha1",
+  "kind": "ValidatingPolicy",
+  "metadata": {
+    "name": "cap-013-adapter-dedup",
+    "annotations": {
+      "nova.cloudinit.dev/severity": "medium",
+      "title.policy.kyverno.io": "No duplicate adapter registrations (CAP-013 declarative mirror)"
+    }
+  },
+  "spec": {
+    "rules": [
+      {
+        "name": "no-duplicate-adapters",
+        "validate": {
+          "message": "Each adapter must be registered exactly once (no duplicate adapter names in the capability inventory). Declarative mirror of core/regression_verify.py CAP-013.",
+          "assert": {
+            "all": [
+              {
+                "check": {
+                  "adapters": "(length(duplicates(@)) == `0`)"
+                }
+              }
+            ]
+          }
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/adapters/kyverno-json/policies/regression/cap-023-metrics-collector.json b/adapters/kyverno-json/policies/regression/cap-023-metrics-collector.json
new file mode 100644
index 0000000..59d3e58
--- /dev/null
+++ b/adapters/kyverno-json/policies/regression/cap-023-metrics-collector.json
@@ -0,0 +1,32 @@
+{
+  "apiVersion": "json.kyverno.io/v1alpha1",
+  "kind": "ValidatingPolicy",
+  "metadata": {
+    "name": "cap-023-metrics-collector",
+    "annotations": {
+      "nova.cloudinit.dev/severity": "medium",
+      "title.policy.kyverno.io": "Every metric has a grounded/derived/deferred status (CAP-023 declarative mirror)"
+    }
+  },
+  "spec": {
+    "rules": [
+      {
+        "name": "every-metric-has-status",
+        "validate": {
+          "message": "Every metric in docs/METRICS.md must declare a status (grounded, derived, or deferred). Declarative mirror of core/regression_verify.py CAP-023.",
+          "assert": {
+            "all": [
+              {
+                "check": {
+                  "~.metrics": {
+                    "(contains(['grounded','derived','deferred'], status))": true
+                  }
+                }
+              }
+            ]
+          }
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/adapters/kyverno-json/policies/regression/cap-024-deck-structure.json b/adapters/kyverno-json/policies/regression/cap-024-deck-structure.json
new file mode 100644
index 0000000..be39624
--- /dev/null
+++ b/adapters/kyverno-json/policies/regression/cap-024-deck-structure.json
@@ -0,0 +1,35 @@
+{
+  "apiVersion": "json.kyverno.io/v1alpha1",
+  "kind": "ValidatingPolicy",
+  "metadata": {
+    "name": "cap-024-deck-structure",
+    "annotations": {
+      "nova.cloudinit.dev/severity": "low",
+      "title.policy.kyverno.io": "Deck structure matches the documented 4-beat arc (CAP-024 declarative mirror)"
+    }
+  },
+  "spec": {
+    "rules": [
+      {
+        "name": "deck-has-4-beats",
+        "validate": {
+          "message": "The deck must have the 4-beat arc: Problem, Solution, Proof, Roadmap+Ask. Declarative mirror of core/regression_verify.py CAP-024.",
+          "assert": {
+            "all": [
+              {
+                "check": {
+                  "deck.beats": "(length(@) >= `4`)"
+                }
+              },
+              {
+                "check": {
+                  "deck.beats": "(contains(@, 'Problem') && contains(@, 'Solution') && contains(@, 'Proof') && contains(@, 'Roadmap+Ask'))"
+                }
+              }
+            ]
+          }
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/docs/METRICS.md b/docs/METRICS.md
index f30d89b..21c8ba6 100644
--- a/docs/METRICS.md
+++ b/docs/METRICS.md
@@ -174,4 +174,18 @@ numbers. Every metric either has a real source or is explicitly deferred.
 | SLA / Unplanned Downtime | D-096 | `placeholder_sla_downtime.csv` |
 | Predictive vs Reactive Ratio | future emitter | `placeholder_predictive_reactive.csv` |
 
-See `docs/METRICS_DEFERRED_ROADMAP.md` for the activation path for each.
\ No newline at end of file
+See `docs/METRICS_DEFERRED_ROADMAP.md` for the activation path for each.
+
+---
+
+## v1.25 — Swappable Policy Engine
+
+The policy engine that produces the `PolicyCheckResult` records feeding
+the confidence signal is **swappable** (NORTH_STAR Strategic Objective #2
+— provable trust via a replaceable substrate, not a vendor lock-in).
+The `PolicyEngine` protocol (`core/policy_engine.py`) is the swap
+boundary; `config.json.policy.engine` selects the active engine
+(default `"kyverno-json"`). A future `OpaEngine` implements the same
+protocol without touching the confidence signal, the PCR schema, or
+the pipeline. See `.ciagent/ARCHITECTURE.md` §12.7 for the registry
+diagram.
\ No newline at end of file
diff --git a/modules/STANDARDS.md b/modules/STANDARDS.md
index 3b38437..895d0c3 100644
--- a/modules/STANDARDS.md
+++ b/modules/STANDARDS.md
@@ -611,4 +611,64 @@ must be checked before the module is registered and published.
   `stack.schema.json`).
 - [ ] For an L2, a test is added that the composition resolves to the
   expected set of L1 instances and that the adapter emits a root module
-  calling the L1 modules.
\ No newline at end of file
+  calling the L1 modules.
+
+---
+
+## 10. Policy Authoring Standard (v1.25)
+
+Module owners may ship per-module kyverno-json policies in
+`modules/<name>/policies/` (future convention; v1.25 policies live
+under `adapters/kyverno-json/policies/`). A policy file is a
+`ValidatingPolicy` resource (YAML or JSON).
+
+### 10.1 Required fields
+
+- `apiVersion: json.kyverno.io/v1alpha1`
+- `kind: ValidatingPolicy`
+- `metadata.name` — matches the filename (e.g. `require-tags.json` →
+  `name: require-tags`). This becomes the `ruleId` prefix `KJ_<name>`.
+- `metadata.annotations["nova.cloudinit.dev/severity"]` — one of
+  `critical`, `high`, `medium`, `low`, `info`. Drives the confidence
+  signal's penalty mapping.
+- `spec.rules[].validate.assert` — an `all` or `any` list of assertion
+  trees with JMESPath expressions. **No `forEach`, pattern operators,
+  anchors, or wildcards** — use the `~` projection modifier to iterate.
+
+### 10.2 Severity guidance
+
+| Severity | When to use | Confidence penalty |
+| --- | --- | --- |
+| `critical` | a violation makes the deploy unsafe (e.g. public ingress on a prod DB) | hard override (score = 0, block) |
+| `high` | a violation is a security or compliance gap (e.g. plaintext secrets) | -0.20 |
+| `medium` | a violation is a best-practice miss (e.g. missing tags) | -0.05 |
+| `low` | a violation is a style or convention issue | -0.01 |
+| `info` | a non-blocking observation (default) | 0.0 |
+
+### 10.3 Assertion-tree patterns
+
+- **Iterate an array:** use the `~` modifier on the array key:
+  ```yaml
+  check:
+    ~.resources:
+      (@ < `5`): true
+  ```
+- **Match a resource type:** use the `match.any` block:
+  ```yaml
+  match:
+    any:
+      - type: aws:s3:bucket
+  ```
+- **Binding for descendant access:** use `->name`:
+  ```yaml
+  (bar + bat)->sum:
+    ($sum): 10
+  ```
+
+### 10.4 Testing
+
+- Ship a fixture pair (`passing.json` + `failing.json`) under
+  `tests/fixtures/<policy_target>/`.
+- Add a test file `tests/test_<policy_target>_policies.py` using the
+  `KyvernoJsonEngine` (skip-without-kj pattern).
+- The regression gate (`pytest tests/`) must remain green.
\ No newline at end of file
diff --git a/schemas/README.md b/schemas/README.md
index e56b7aa..0867a7d 100644
--- a/schemas/README.md
+++ b/schemas/README.md
@@ -15,6 +15,14 @@ Nova uses JSON Schema draft 2020-12 for all declarative contracts. Schemas are t
 | Nova PolicyCheckResult | `policy_check_result.schema.json` | Normalized policy check result schema (the contract between policy engines and the confidence signal) | `tests/conftest.py`, all adapter tests |
 | Nova Tagging Standard | `tagging-standard.json` | Required tag set for all taggable AWS resources | `adapters/terraform/policy/custom_rules/nova_tagging.py` |
 
+> **v1.25 note (D-116):** the `engine` enum value `"kyverno"` is shared
+> by the K8s-only Kyverno adapter (`adapters/kyverno/`) and the
+> kyverno-json engine (`adapters/kyverno-json/`). The two are
+> distinguished by `ruleId` prefix (`KYVERNO_` for the K8s adapter,
+> `KJ_` for kyverno-json) and `evidence` payload shape. No new enum
+> value was added — the `engine` field records the policy-engine
+> family, not the specific binary.
+
 ## How to Write a Schema
 
 1. Use JSON Schema draft 2020-12: `"$schema": "https://json-schema.org/draft/2020-12/schema"`.
diff --git a/tests/fixtures/capability_inventory/clean.json b/tests/fixtures/capability_inventory/clean.json
new file mode 100644
index 0000000..9248997
--- /dev/null
+++ b/tests/fixtures/capability_inventory/clean.json
@@ -0,0 +1,11 @@
+{
+  "adapters": ["terraform", "checkov", "wiz", "kyverno-json"],
+  "metrics": [
+    {"name": "MTTR", "status": "grounded"},
+    {"name": "CloudSpend", "status": "derived"},
+    {"name": "TouchlessResolution", "status": "deferred"}
+  ],
+  "deck": {
+    "beats": ["Problem", "Solution", "Proof", "Roadmap+Ask"]
+  }
+}
\ No newline at end of file
diff --git a/tests/fixtures/capability_inventory/drifted.json b/tests/fixtures/capability_inventory/drifted.json
new file mode 100644
index 0000000..1b3e1b7
--- /dev/null
+++ b/tests/fixtures/capability_inventory/drifted.json
@@ -0,0 +1,11 @@
+{
+  "adapters": ["terraform", "checkov", "wiz", "terraform", "kyverno-json"],
+  "metrics": [
+    {"name": "MTTR", "status": "grounded"},
+    {"name": "CloudSpend", "status": "unknown"},
+    {"name": "TouchlessResolution", "status": "deferred"}
+  ],
+  "deck": {
+    "beats": ["Problem", "Solution", "Proof"]
+  }
+}
\ No newline at end of file
diff --git a/tests/test_regression_policies.py b/tests/test_regression_policies.py
new file mode 100644
index 0000000..a5ab90b
--- /dev/null
+++ b/tests/test_regression_policies.py
@@ -0,0 +1,88 @@
+"""Tests for regression-gate kyverno-json policies (REQ-304, REQ-305, v1.25).
+
+Tests the 3 declarative mirrors of core/regression_verify.py:
+cap-013-adapter-dedup, cap-023-metrics-collector, cap-024-deck-structure.
+Uses clean + drifted capability-inventory fixtures. Skip-without-kj.
+"""
+
+import json
+import os
+import sys
+from pathlib import Path
+
+import pytest
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import importlib.util
+_ENGINE_PATH = Path(__file__).resolve().parent.parent / "adapters" / "kyverno-json" / "kyverno_json_engine.py"
+_spec = importlib.util.spec_from_file_location("kyverno_json_engine", _ENGINE_PATH)
+_mod = importlib.util.module_from_spec(_spec)
+_spec.loader.exec_module(_mod)
+KyvernoJsonEngine = _mod.KyvernoJsonEngine
+
+POLICY_DIR = Path(__file__).resolve().parent.parent / "adapters" / "kyverno-json" / "policies" / "regression"
+FIXTURES = Path(__file__).resolve().parent / "fixtures" / "capability_inventory"
+
+
+def _kj_installed() -> bool:
+    return _mod._which_kj() is not None
+
+
+@pytest.fixture(autouse=True)
+def _require_kj():
+    if not _kj_installed():
+        pytest.skip("kj not installed (scripts/install-kyverno-json.sh)")
+
+
+def _load(name):
+    with open(FIXTURES / name, "r", encoding="utf-8") as fh:
+        return json.load(fh)
+
+
+class TestCleanInventory:
+    def test_clean_inventory_no_fails(self):
+        eng = KyvernoJsonEngine()
+        out = eng.evaluate(_load("clean.json"), POLICY_DIR, "cid-clean")
+        fails = [p for p in out if p["result"] == "fail"]
+        assert fails == [], f"expected no fails on clean inventory, got: {fails}"
+
+
+class TestDriftedInventory:
+    def test_drifted_inventory_has_fails(self):
+        eng = KyvernoJsonEngine()
+        out = eng.evaluate(_load("drifted.json"), POLICY_DIR, "cid-drift")
+        fails = [p for p in out if p["result"] == "fail"]
+        assert len(fails) >= 1, "expected at least one fail on the drifted inventory"
+
+
+class TestPolicyFilesExist:
+    def test_three_regression_policies_present(self):
+        files = sorted(os.listdir(POLICY_DIR))
+        assert "cap-013-adapter-dedup.json" in files
+        assert "cap-023-metrics-collector.json" in files
+        assert "cap-024-deck-structure.json" in files
+
+    def test_policies_are_valid_json(self):
+        for f in os.listdir(POLICY_DIR):
+            if f.endswith(".json"):
+                with open(POLICY_DIR / f, "r", encoding="utf-8") as fh:
+                    data = json.load(fh)
+                assert data["apiVersion"] == "json.kyverno.io/v1alpha1"
+                assert data["kind"] == "ValidatingPolicy"
+                assert "nova.cloudinit.dev/severity" in data["metadata"]["annotations"]
+
+
+class TestFixturesExist:
+    def test_clean_and_drifted_fixtures_present(self):
+        assert (FIXTURES / "clean.json").is_file()
+        assert (FIXTURES / "drifted.json").is_file()
+
+    def test_drifted_fixture_has_duplicate_adapter(self):
+        data = _load("drifted.json")
+        # The drifted fixture has 'terraform' twice (adapter dedup violation).
+        assert data["adapters"].count("terraform") == 2
+
+    def test_drifted_fixture_has_missing_roadmap_beat(self):
+        data = _load("drifted.json")
+        assert "Roadmap+Ask" not in data["deck"]["beats"]
\ No newline at end of file