sinkog · Oct 19, 2026 · Oct 18, 2026 · Oct 18, 2026
diff --git a/README.md b/README.md
@@ -101,7 +101,20 @@ correction to the pipeline framing this file used to carry.
 > correction below, had zero internal callers, and keeping it around
 > would have let the tree imply a scope the contract now denies; see
 > "What does not belong here" for why removal, not just naming the gap,
-> was the right close. Nothing here is a stable API.
+> was the right close.
+>
+> **The conformance/drift verdict artifact exists in both languages:**
+> `engine/src/verdict.rs` and `go/verdict` assemble the five required fields
+> of `docs/VERDICT-SCHEMA.md` (`verdict_schema_version: 1`) from `evaluate`'s
+> result and the existing digest projections, refuse an inconsistent result
+> (`E_INCONSISTENT_VERDICT`), and are cross-checked byte-for-byte through
+> `conformance/differential/verdict/`, including a test that the corpus
+> detects deliberate divergence.
+> `evaluate_verdict`/`verdict.EvaluateAndBuild` is the primary entry point (plan and
+> result are bound by construction); `build_verdict`/`verdict.Build` is the
+> low-level assembler and checks structure only -- see `docs/VERDICT-SCHEMA.md`.
+>
+> Nothing here is a stable API.
 
 ---
 

diff --git a/conformance/differential/README.md b/conformance/differential/README.md
@@ -42,6 +42,7 @@ differential/
   plan/          -- F8: plan.Evaluate
   digest/        -- F9: digestprojection.*
   materialized/  -- MaterializedObject::try_new / NewMaterializedObject
+  verdict/       -- the assembled five-field verdict artifact (build_verdict / verdict.Build)
 ```
 
 One group per primitive, landed incrementally — matching how F6
@@ -203,3 +204,20 @@ is, only whether both sides agree on being numeric or not) — so no
 vector here depends on it — but a future vector author relying on
 exact-comparator behavior that distinguishes `16` from `16.0` by
 *spelling* would hit a real asymmetry this layer does not paper over.
+
+### `verdict/`
+
+```text
+input.json:     the `plan/` group's input (intent, observed, observation, plan), plus an
+                optional `tamper` list of edits to the evaluate result before the artifact
+                is built: {op: drop_consumed|add_consumed|drop_field|set_object, path|value}
+expected.json:  an artifact vector: {verdict: <the five-key tree>, canonical: <its canonical
+                bytes as a string>}
+                a refusal vector:   {error: {code, path}}
+```
+
+Both languages must produce the identical canonical bytes, and a success
+vector's `object`/`fields` must equal the same-named `plan/` vector's pin. A
+second test per language applies eight deliberate divergences to a correct
+artifact and requires the comparison to catch each.
+
diff --git a/conformance/differential/verdict/multi_key_collection_identity/expected.json b/conformance/differential/verdict/multi_key_collection_identity/expected.json
@@ -0,0 +1,13 @@
+{
+  "verdict": {
+    "conformance_plan_digest": "sha256:deb83850cc0f689d6f0c643694567125bae9b2268bdaa6cf5ac20dddf1094683",
+    "fields": {
+      "/nics/{name=nic-0,zone=eu}/subnet": "DRIFT"
+    },
+    "object": "DRIFT",
+    "observation_digest": "sha256:66fe8f76ccc06b0722d74a23fcd893e4167dcd3e6942218e1e6e08a60f333a72",
+    "verdict_schema_version": 1
+  },
+  "canonical": "{\"conformance_plan_digest\":\"sha256:deb83850cc0f689d6f0c643694567125bae9b2268bdaa6cf5ac20dddf1094683\",\"fields\":{\"/nics/{name=nic-0,zone=eu}/subnet\":\"DRIFT\"},\"object\":\"DRIFT\",\"observation_digest\":\"sha256:66fe8f76ccc06b0722d74a23fcd893e4167dcd3e6942218e1e6e08a60f333a72\",\"verdict_schema_version\":1}",
+  "why": "a multi-key element identity is part of the evaluated path in fields"
+}
diff --git a/conformance/differential/verdict/multi_key_collection_identity/input.json b/conformance/differential/verdict/multi_key_collection_identity/input.json
@@ -0,0 +1,26 @@
+{
+  "intent": {
+    "nics": [
+      {"name": "nic-0", "zone": "eu", "subnet": "prod-a"}
+    ]
+  },
+  "observed": {
+    "nics": [
+      {"name": "nic-0", "zone": "eu", "subnet": "prod-WRONG"}
+    ]
+  },
+  "observation": [
+    {"path": "/nics/{name=nic-0,zone=eu}/subnet", "coverage": "observed"}
+  ],
+  "plan": {
+    "scalars": [],
+    "collections": [
+      {
+        "path": "/nics",
+        "topology": "map",
+        "keys": ["name", "zone"],
+        "elements": [{"path": "subnet", "compare": "exact"}]
+      }
+    ]
+  }
+}
diff --git a/conformance/differential/verdict/oci_conformant/expected.json b/conformance/differential/verdict/oci_conformant/expected.json
@@ -0,0 +1,16 @@
+{
+  "verdict": {
+    "conformance_plan_digest": "sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850",
+    "fields": {
+      "/memory_gb": "CONFORMANT",
+      "/network_interfaces/{name=nic-0}/subnet": "CONFORMANT",
+      "/network_interfaces/{name=nic-1}/subnet": "CONFORMANT",
+      "/shape": "CONFORMANT"
+    },
+    "object": "CONFORMANT",
+    "observation_digest": "sha256:5e24b8bb061a32c1ee09f8ede05374d7b13cfd89798985eb1a426781c93c2fe5",
+    "verdict_schema_version": 1
+  },
+  "canonical": "{\"conformance_plan_digest\":\"sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850\",\"fields\":{\"/memory_gb\":\"CONFORMANT\",\"/network_interfaces/{name=nic-0}/subnet\":\"CONFORMANT\",\"/network_interfaces/{name=nic-1}/subnet\":\"CONFORMANT\",\"/shape\":\"CONFORMANT\"},\"object\":\"CONFORMANT\",\"observation_digest\":\"sha256:5e24b8bb061a32c1ee09f8ede05374d7b13cfd89798985eb1a426781c93c2fe5\",\"verdict_schema_version\":1}",
+  "why": "every planned field matches: the artifact carries the CONFORMANT object verdict, the four evaluated paths, and the two digests"
+}
diff --git a/conformance/differential/verdict/oci_conformant/input.json b/conformance/differential/verdict/oci_conformant/input.json
@@ -0,0 +1,40 @@
+{
+  "intent": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observed": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16.0,
+    "provider_id": "ocid1.instance.oc1..aaaa",
+    "lifecycle_state": "RUNNING",
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}, "private_ip": "10.0.1.17"},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}, "private_ip": "10.0.2.9"}
+    ]
+  },
+  "observation": [
+    {"path": "/shape", "coverage": "observed"},
+    {"path": "/memory_gb", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-0}/subnet", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-1}/subnet", "coverage": "observed"}
+  ],
+  "plan": {
+    "scalars": [
+      {"path": "/shape", "compare": "exact"},
+      {"path": "/memory_gb", "compare": "numeric"}
+    ],
+    "collections": [
+      {
+        "path": "/network_interfaces",
+        "topology": "map",
+        "keys": ["name"],
+        "elements": [{"path": "subnet", "compare": "exact"}]
+      }
+    ]
+  }
+}
diff --git a/conformance/differential/verdict/oci_desired_absent_is_conformant/expected.json b/conformance/differential/verdict/oci_desired_absent_is_conformant/expected.json
@@ -0,0 +1,17 @@
+{
+  "verdict": {
+    "conformance_plan_digest": "sha256:928988250ac70e1fc043022a372c2d72b5aa3a3018f98ac84ad3faa36e086fc4",
+    "fields": {
+      "/boot_volume": "OBSERVED_ABSENT",
+      "/memory_gb": "CONFORMANT",
+      "/network_interfaces/{name=nic-0}/subnet": "CONFORMANT",
+      "/network_interfaces/{name=nic-1}/subnet": "CONFORMANT",
+      "/shape": "CONFORMANT"
+    },
+    "object": "CONFORMANT",
+    "observation_digest": "sha256:449a85439d54f9c4497e80ec85070a927a8519f9e619728f8d83760d241885ab",
+    "verdict_schema_version": 1
+  },
+  "canonical": "{\"conformance_plan_digest\":\"sha256:928988250ac70e1fc043022a372c2d72b5aa3a3018f98ac84ad3faa36e086fc4\",\"fields\":{\"/boot_volume\":\"OBSERVED_ABSENT\",\"/memory_gb\":\"CONFORMANT\",\"/network_interfaces/{name=nic-0}/subnet\":\"CONFORMANT\",\"/network_interfaces/{name=nic-1}/subnet\":\"CONFORMANT\",\"/shape\":\"CONFORMANT\"},\"object\":\"CONFORMANT\",\"observation_digest\":\"sha256:449a85439d54f9c4497e80ec85070a927a8519f9e619728f8d83760d241885ab\",\"verdict_schema_version\":1}",
+  "why": "a field the intent does not declare and the observation finds absent is OBSERVED_ABSENT and does not drift the object"
+}
diff --git a/conformance/differential/verdict/oci_desired_absent_is_conformant/input.json b/conformance/differential/verdict/oci_desired_absent_is_conformant/input.json
@@ -0,0 +1,40 @@
+{
+  "intent": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observed": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16.0,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observation": [
+    {"path": "/shape", "coverage": "observed"},
+    {"path": "/memory_gb", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-0}/subnet", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-1}/subnet", "coverage": "observed"},
+    {"path": "/boot_volume", "coverage": "absent"}
+  ],
+  "plan": {
+    "scalars": [
+      {"path": "/shape", "compare": "exact"},
+      {"path": "/memory_gb", "compare": "numeric"},
+      {"path": "/boot_volume", "compare": "exact"}
+    ],
+    "collections": [
+      {
+        "path": "/network_interfaces",
+        "topology": "map",
+        "keys": ["name"],
+        "elements": [{"path": "subnet", "compare": "exact"}]
+      }
+    ]
+  }
+}
diff --git a/conformance/differential/verdict/oci_drift/expected.json b/conformance/differential/verdict/oci_drift/expected.json
@@ -0,0 +1,16 @@
+{
+  "verdict": {
+    "conformance_plan_digest": "sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850",
+    "fields": {
+      "/memory_gb": "CONFORMANT",
+      "/network_interfaces/{name=nic-0}/subnet": "CONFORMANT",
+      "/network_interfaces/{name=nic-1}/subnet": "DRIFT",
+      "/shape": "CONFORMANT"
+    },
+    "object": "DRIFT",
+    "observation_digest": "sha256:69ec2c422d32b89c8bd0d060296982e8172e8fd6084984aee65c8325dd47a39f",
+    "verdict_schema_version": 1
+  },
+  "canonical": "{\"conformance_plan_digest\":\"sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850\",\"fields\":{\"/memory_gb\":\"CONFORMANT\",\"/network_interfaces/{name=nic-0}/subnet\":\"CONFORMANT\",\"/network_interfaces/{name=nic-1}/subnet\":\"DRIFT\",\"/shape\":\"CONFORMANT\"},\"object\":\"DRIFT\",\"observation_digest\":\"sha256:69ec2c422d32b89c8bd0d060296982e8172e8fd6084984aee65c8325dd47a39f\",\"verdict_schema_version\":1}",
+  "why": "a single element subnet mismatch drifts only that field; the artifact aggregates to DRIFT and still lists every evaluated path"
+}
diff --git a/conformance/differential/verdict/oci_drift/input.json b/conformance/differential/verdict/oci_drift/input.json
@@ -0,0 +1,38 @@
+{
+  "intent": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observed": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16.0,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-WRONG", "kind": "Subnet"}}
+    ]
+  },
+  "observation": [
+    {"path": "/shape", "coverage": "observed"},
+    {"path": "/memory_gb", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-0}/subnet", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-1}/subnet", "coverage": "observed"}
+  ],
+  "plan": {
+    "scalars": [
+      {"path": "/shape", "compare": "exact"},
+      {"path": "/memory_gb", "compare": "numeric"}
+    ],
+    "collections": [
+      {
+        "path": "/network_interfaces",
+        "topology": "map",
+        "keys": ["name"],
+        "elements": [{"path": "subnet", "compare": "exact"}]
+      }
+    ]
+  }
+}
diff --git a/conformance/differential/verdict/oci_not_comparable/expected.json b/conformance/differential/verdict/oci_not_comparable/expected.json
@@ -0,0 +1,16 @@
+{
+  "verdict": {
+    "conformance_plan_digest": "sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850",
+    "fields": {
+      "/memory_gb": "NOT_COMPARABLE",
+      "/network_interfaces/{name=nic-0}/subnet": "CONFORMANT",
+      "/network_interfaces/{name=nic-1}/subnet": "CONFORMANT",
+      "/shape": "CONFORMANT"
+    },
+    "object": "DRIFT",
+    "observation_digest": "sha256:10e27324b2fd39a6ed030ed9861e54e06e00634a159e16cceb346b510daf8e2b",
+    "verdict_schema_version": 1
+  },
+  "canonical": "{\"conformance_plan_digest\":\"sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850\",\"fields\":{\"/memory_gb\":\"NOT_COMPARABLE\",\"/network_interfaces/{name=nic-0}/subnet\":\"CONFORMANT\",\"/network_interfaces/{name=nic-1}/subnet\":\"CONFORMANT\",\"/shape\":\"CONFORMANT\"},\"object\":\"DRIFT\",\"observation_digest\":\"sha256:10e27324b2fd39a6ed030ed9861e54e06e00634a159e16cceb346b510daf8e2b\",\"verdict_schema_version\":1}",
+  "why": "an incomparable field makes the object DRIFT; the artifact keeps NOT_COMPARABLE as the field verdict"
+}
diff --git a/conformance/differential/verdict/oci_not_comparable/input.json b/conformance/differential/verdict/oci_not_comparable/input.json
@@ -0,0 +1,38 @@
+{
+  "intent": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observed": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": "large",
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observation": [
+    {"path": "/shape", "coverage": "observed"},
+    {"path": "/memory_gb", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-0}/subnet", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-1}/subnet", "coverage": "observed"}
+  ],
+  "plan": {
+    "scalars": [
+      {"path": "/shape", "compare": "exact"},
+      {"path": "/memory_gb", "compare": "numeric"}
+    ],
+    "collections": [
+      {
+        "path": "/network_interfaces",
+        "topology": "map",
+        "keys": ["name"],
+        "elements": [{"path": "subnet", "compare": "exact"}]
+      }
+    ]
+  }
+}
diff --git a/conformance/differential/verdict/oci_unobserved/expected.json b/conformance/differential/verdict/oci_unobserved/expected.json
@@ -0,0 +1,16 @@
+{
+  "verdict": {
+    "conformance_plan_digest": "sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850",
+    "fields": {
+      "/memory_gb": "UNOBSERVED",
+      "/network_interfaces/{name=nic-0}/subnet": "CONFORMANT",
+      "/network_interfaces/{name=nic-1}/subnet": "CONFORMANT",
+      "/shape": "CONFORMANT"
+    },
+    "object": "INCOMPLETE",
+    "observation_digest": "sha256:7afeba3ff68ab2ce4f789c4dae85727371a75120e9f458a4c3b8c9c39ee692e3",
+    "verdict_schema_version": 1
+  },
+  "canonical": "{\"conformance_plan_digest\":\"sha256:d973c7d2e9cf02f49ad1f59889a0dd2aaabd98b41d30c07377c63fdafd387850\",\"fields\":{\"/memory_gb\":\"UNOBSERVED\",\"/network_interfaces/{name=nic-0}/subnet\":\"CONFORMANT\",\"/network_interfaces/{name=nic-1}/subnet\":\"CONFORMANT\",\"/shape\":\"CONFORMANT\"},\"object\":\"INCOMPLETE\",\"observation_digest\":\"sha256:7afeba3ff68ab2ce4f789c4dae85727371a75120e9f458a4c3b8c9c39ee692e3\",\"verdict_schema_version\":1}",
+  "why": "a planned field that was not observed makes the object INCOMPLETE; the observation digest changes with the coverage"
+}
diff --git a/conformance/differential/verdict/oci_unobserved/input.json b/conformance/differential/verdict/oci_unobserved/input.json
@@ -0,0 +1,37 @@
+{
+  "intent": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observed": {
+    "shape": "VM.Standard.E4.Flex",
+    "memory_gb": 16.0,
+    "network_interfaces": [
+      {"name": "nic-0", "subnet": {"ref": "prod-subnet-a", "kind": "Subnet"}},
+      {"name": "nic-1", "subnet": {"ref": "prod-subnet-b", "kind": "Subnet"}}
+    ]
+  },
+  "observation": [
+    {"path": "/shape", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-0}/subnet", "coverage": "observed"},
+    {"path": "/network_interfaces/{name=nic-1}/subnet", "coverage": "observed"}
+  ],
+  "plan": {
+    "scalars": [
+      {"path": "/shape", "compare": "exact"},
+      {"path": "/memory_gb", "compare": "numeric"}
+    ],
+    "collections": [
+      {
+        "path": "/network_interfaces",
+        "topology": "map",
+        "keys": ["name"],
+        "elements": [{"path": "subnet", "compare": "exact"}]
+      }
+    ]
+  }
+}
diff --git a/conformance/differential/verdict/tampered_evidence_for_unclassified_path/expected.json b/conformance/differential/verdict/tampered_evidence_for_unclassified_path/expected.json
@@ -0,0 +1,7 @@
+{
+  "error": {
+    "code": "E_INCONSISTENT_VERDICT",
+    "path": "/ghost"
+  },
+  "why": "a result that cannot be an evaluate result for the plan is refused, never digested into an artifact"
+}