diff --git a/Makefile b/Makefile
index 8856a654..cead0039 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
-.PHONY: validate test validate-agent-cycle-health validate-authority-dependency-evidence validate-prometheus-sr validate-reasoning-failure-traces validate-governance-context validate-lattice-data-governai-execution-refs validate-lattice-runtime-profile-refs validate-network-native-assistant-evidence validate-guardrail-evidence-artifacts validate-stop-gate-evaluator validate-guarded-workcell-artifact validate-guarded-workcell-executor validate-guarded-invocation-artifact validate-guarded-invocation validate-agentic-pr-work-order validate-semantic-enterprise-agent-boundary validate-ops-history-contracts validate-action-contracts validate-agent-operation-contract validate-superconscious-reasoning-import validate-agent-harness-runtime-contracts validate-bounded-action-loop agentplane-evidence-receipt-composition-tier2-binding-ci lawful-learning-phase9-contract-ci validate-evidence-receipt-binding validate-semantic-activation-receipt validate-governed-run-contract validate-preflight-receipt validate-attempt-admission-receipt validate-verification-execution-receipt validate-synthetic-verification-receipt validate-governed-runner-v0-2-contract-chain validate-budget-settlement-receipt validate-rollback-receipts validate-run-dossier validate-governed-runner-readonly validate-workroom-context-evidence validate-wallguard-collaboration-admission validate-prophet-mesh-agentplane-adapter
+.PHONY: validate test validate-agent-cycle-health validate-authority-dependency-evidence validate-prometheus-sr validate-reasoning-failure-traces validate-governance-context validate-lattice-data-governai-execution-refs validate-lattice-runtime-profile-refs validate-network-native-assistant-evidence validate-guardrail-evidence-artifacts validate-stop-gate-evaluator validate-guarded-workcell-artifact validate-guarded-workcell-executor validate-guarded-invocation-artifact validate-guarded-invocation validate-agentic-pr-work-order validate-semantic-enterprise-agent-boundary validate-ops-history-contracts validate-action-contracts validate-agent-operation-contract validate-superconscious-reasoning-import validate-agent-harness-runtime-contracts validate-bounded-action-loop agentplane-evidence-receipt-composition-tier2-binding-ci lawful-learning-phase9-contract-ci validate-evidence-receipt-binding validate-semantic-activation-receipt validate-governed-run-contract validate-preflight-receipt validate-attempt-admission-receipt validate-verification-execution-receipt validate-synthetic-verification-receipt validate-governed-runner-v0-2-contract-chain validate-budget-settlement-receipt validate-rollback-receipts validate-run-dossier validate-governed-runner-readonly validate-workroom-context-evidence validate-wallguard-collaboration-admission validate-prophet-mesh-agentplane-adapter validate-epigov-artifacts
 
-validate: validate-agent-cycle-health validate-authority-dependency-evidence validate-prometheus-sr validate-reasoning-failure-traces validate-governance-context validate-lattice-data-governai-execution-refs validate-lattice-runtime-profile-refs validate-network-native-assistant-evidence validate-guardrail-evidence-artifacts validate-stop-gate-evaluator validate-guarded-workcell-artifact validate-guarded-workcell-executor validate-guarded-invocation-artifact validate-guarded-invocation validate-agentic-pr-work-order validate-semantic-enterprise-agent-boundary validate-ops-history-contracts validate-action-contracts validate-agent-operation-contract validate-superconscious-reasoning-import validate-agent-harness-runtime-contracts validate-bounded-action-loop agentplane-evidence-receipt-composition-tier2-binding-ci lawful-learning-phase9-contract-ci validate-evidence-receipt-binding validate-semantic-activation-receipt validate-governed-run-contract validate-preflight-receipt validate-attempt-admission-receipt validate-verification-execution-receipt validate-synthetic-verification-receipt validate-governed-runner-v0-2-contract-chain validate-budget-settlement-receipt validate-rollback-receipts validate-run-dossier validate-governed-runner-readonly validate-workroom-context-evidence validate-wallguard-collaboration-admission validate-prophet-mesh-agentplane-adapter
+validate: validate-agent-cycle-health validate-authority-dependency-evidence validate-prometheus-sr validate-reasoning-failure-traces validate-governance-context validate-lattice-data-governai-execution-refs validate-lattice-runtime-profile-refs validate-network-native-assistant-evidence validate-guardrail-evidence-artifacts validate-stop-gate-evaluator validate-guarded-workcell-artifact validate-guarded-workcell-executor validate-guarded-invocation-artifact validate-guarded-invocation validate-agentic-pr-work-order validate-semantic-enterprise-agent-boundary validate-ops-history-contracts validate-action-contracts validate-agent-operation-contract validate-superconscious-reasoning-import validate-agent-harness-runtime-contracts validate-bounded-action-loop agentplane-evidence-receipt-composition-tier2-binding-ci lawful-learning-phase9-contract-ci validate-evidence-receipt-binding validate-semantic-activation-receipt validate-governed-run-contract validate-preflight-receipt validate-attempt-admission-receipt validate-verification-execution-receipt validate-synthetic-verification-receipt validate-governed-runner-v0-2-contract-chain validate-budget-settlement-receipt validate-rollback-receipts validate-run-dossier validate-governed-runner-readonly validate-workroom-context-evidence validate-wallguard-collaboration-admission validate-prophet-mesh-agentplane-adapter validate-epigov-artifacts
 	python3 tools/validate_execution_timing.py
 
 validate-governance-context:
@@ -248,6 +248,9 @@ validate-prophet-mesh-agentplane-adapter:
 	python3 -m json.tool contracts/prophet-mesh/prophet-mesh-agentplane-adapter.v0.1.json >/dev/null
 	python3 tools/validate_prophet_mesh_agentplane_adapter.py
 
+validate-epigov-artifacts:
+	python3 tools/validate_epigov_artifacts.py
+
 validate-agent-cycle-health:
 	python3 tools/validate_agent_cycle_health.py
 
diff --git a/bundles/epigov-countertest-smoke/bundle.json b/bundles/epigov-countertest-smoke/bundle.json
new file mode 100644
index 00000000..c36de58d
--- /dev/null
+++ b/bundles/epigov-countertest-smoke/bundle.json
@@ -0,0 +1,40 @@
+{
+  "apiVersion": "agentplane.socioprophet.org/v0.1",
+  "kind": "Bundle",
+  "metadata": {
+    "name": "epigov-countertest-smoke",
+    "version": "0.1.0",
+    "createdAt": "2026-06-11T00:00:00Z",
+    "licensePolicy": {
+      "allowAGPL": false,
+      "notes": "Epistemic governance counter-test bundle. Evidence-forward."
+    },
+    "source": { "git": { "dirty": false, "rev": "UNSET" } }
+  },
+  "spec": {
+    "upstreamAnchors": [
+      "SocioProphet/sociosphere#322:epistemic-governance-v0.2.1",
+      "protocol/epistemic-governance/v1"
+    ],
+    "nonClaims": [
+      "This bundle does not grant authority to accept or dismiss hygiene findings.",
+      "This bundle does not implement autonomous adversarial execution.",
+      "This bundle does not self-modify at runtime."
+    ],
+    "artifacts": { "outDir": "./artifacts/epigov-countertest-smoke" },
+    "policy": {
+      "lane": "smoke",
+      "humanGateRequired": false,
+      "failOnTimeout": true,
+      "maxRunSeconds": 60,
+      "policyPackRef": "policy://agentplane/epigov-smoke-v1",
+      "policyPackHash": "UNSET"
+    },
+    "determinism": {
+      "required": true,
+      "note": "Same input + same ruleset hash must produce same counter-test output"
+    },
+    "smoke": { "script": "bundles/epigov-countertest-smoke/smoke.sh" },
+    "secrets": { "required": [], "secretRefRoot": "secrets://tenant" }
+  }
+}
diff --git a/bundles/epigov-hygiene-detector-smoke/bundle.json b/bundles/epigov-hygiene-detector-smoke/bundle.json
new file mode 100644
index 00000000..03963478
--- /dev/null
+++ b/bundles/epigov-hygiene-detector-smoke/bundle.json
@@ -0,0 +1,41 @@
+{
+  "apiVersion": "agentplane.socioprophet.org/v0.1",
+  "kind": "Bundle",
+  "metadata": {
+    "name": "epigov-hygiene-detector-smoke",
+    "version": "0.1.0",
+    "createdAt": "2026-06-11T00:00:00Z",
+    "licensePolicy": {
+      "allowAGPL": false,
+      "notes": "Epistemic governance bundle is evidence-forward. No autonomous adversarial execution."
+    },
+    "source": { "git": { "dirty": false, "rev": "UNSET" } }
+  },
+  "spec": {
+    "upstreamAnchors": [
+      "SocioProphet/sociosphere#322:epistemic-governance-v0.2.1",
+      "protocol/epistemic-governance/v1"
+    ],
+    "nonClaims": [
+      "This bundle does not grant authority to automatically remediate detected hygiene issues.",
+      "This bundle does not implement autonomous adversarial execution.",
+      "This bundle does not self-modify at runtime.",
+      "This bundle does not produce external side effects beyond bounded test artifacts."
+    ],
+    "artifacts": { "outDir": "./artifacts/epigov-hygiene-detector-smoke" },
+    "policy": {
+      "lane": "smoke",
+      "humanGateRequired": false,
+      "failOnTimeout": true,
+      "maxRunSeconds": 60,
+      "policyPackRef": "policy://agentplane/epigov-smoke-v1",
+      "policyPackHash": "UNSET"
+    },
+    "determinism": {
+      "required": true,
+      "note": "Same input + same ruleset hash must produce same detector output"
+    },
+    "smoke": { "script": "bundles/epigov-hygiene-detector-smoke/smoke.sh" },
+    "secrets": { "required": [], "secretRefRoot": "secrets://tenant" }
+  }
+}
diff --git a/bundles/epigov-policy-backtest/bundle.json b/bundles/epigov-policy-backtest/bundle.json
new file mode 100644
index 00000000..0555d20f
--- /dev/null
+++ b/bundles/epigov-policy-backtest/bundle.json
@@ -0,0 +1,37 @@
+{
+  "apiVersion": "agentplane.socioprophet.org/v0.1",
+  "kind": "Bundle",
+  "metadata": {
+    "name": "epigov-policy-backtest",
+    "version": "0.1.0",
+    "createdAt": "2026-06-11T00:00:00Z",
+    "licensePolicy": {
+      "allowAGPL": false,
+      "notes": "Epistemic governance policy backtest bundle. Evidence-forward. No live policy writes."
+    },
+    "source": { "git": { "dirty": false, "rev": "UNSET" } }
+  },
+  "spec": {
+    "upstreamAnchors": [
+      "SocioProphet/sociosphere#322:epistemic-governance-v0.2.1",
+      "protocol/epistemic-governance/v1"
+    ],
+    "nonClaims": [
+      "This bundle does not write or modify live policies.",
+      "This bundle does not implement autonomous adversarial execution.",
+      "This bundle does not self-modify at runtime.",
+      "Backtest results are observational evidence only; they do not constitute policy approval."
+    ],
+    "artifacts": { "outDir": "./artifacts/epigov-policy-backtest" },
+    "policy": {
+      "lane": "backtest",
+      "humanGateRequired": true,
+      "failOnTimeout": true,
+      "maxRunSeconds": 300,
+      "policyPackRef": "policy://agentplane/epigov-backtest-v1",
+      "policyPackHash": "UNSET"
+    },
+    "smoke": { "script": "bundles/epigov-policy-backtest/smoke.sh" },
+    "secrets": { "required": [], "secretRefRoot": "secrets://tenant" }
+  }
+}
diff --git a/examples/receipts/epigov-strawman-smoke/countertest-run-artifact.example.json b/examples/receipts/epigov-strawman-smoke/countertest-run-artifact.example.json
new file mode 100644
index 00000000..7603c1ca
--- /dev/null
+++ b/examples/receipts/epigov-strawman-smoke/countertest-run-artifact.example.json
@@ -0,0 +1,26 @@
+{
+  "kind": "CountertestRunArtifact",
+  "artifact_id": "epigov_countertest_run_strawman_001",
+  "run_ref": "agentplane://run/epigov-countertest-smoke/run_strawman_001",
+  "countertest_id": "CTEST.STEELMAN.CONFIRM.V2",
+  "hygiene_run_ref": "agentplane://run/epigov-hygiene-detector-smoke/run_strawman_001",
+  "input_hash": "sha256:b4e2f1c3d5a6b7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2",
+  "ruleset_hash": "sha256:c5f3e1d2b4a5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1",
+  "findings_addressed": 1,
+  "countertest_outcomes": [
+    {
+      "outcome_id": "ctest_outcome_001",
+      "finding_ref": "finding_strawman_001",
+      "verdict": "confirmed_finding",
+      "steelman_claim": "The strongest interpretation of the position is that it relies on the weakest formulation of the opposing argument; even under charitable reading this remains a strawman.",
+      "counter_evidence_refs": [
+        "evidence://epigov/primary-source/opposing-position-v2"
+      ]
+    }
+  ],
+  "validation_artifact_ref": "agentplane://validation/epigov-countertest-smoke/val_strawman_001",
+  "replay_artifact_ref": "agentplane://replay/epigov-countertest-smoke/replay_strawman_001",
+  "sociosphere_protocol_ref": "protocol/epistemic-governance/v1",
+  "replay_verified": true,
+  "issued_at": "2026-06-11T10:10:00Z"
+}
diff --git a/examples/receipts/epigov-strawman-smoke/hygiene-run-artifact.example.json b/examples/receipts/epigov-strawman-smoke/hygiene-run-artifact.example.json
new file mode 100644
index 00000000..ada9a23b
--- /dev/null
+++ b/examples/receipts/epigov-strawman-smoke/hygiene-run-artifact.example.json
@@ -0,0 +1,30 @@
+{
+  "kind": "HygieneRunArtifact",
+  "artifact_id": "epigov_hygiene_run_strawman_001",
+  "run_ref": "agentplane://run/epigov-hygiene-detector-smoke/run_strawman_001",
+  "detector_id": "LOGFALL.STRAWMAN.V2",
+  "ruleset_hash": "sha256:a3f1e2b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2",
+  "input_hash": "sha256:b4e2f1c3d5a6b7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2",
+  "claims_evaluated": 5,
+  "hygiene_findings": [
+    {
+      "finding_id": "finding_strawman_001",
+      "claim_ref": "claim://epigov/strawman-test/claim_001",
+      "finding_type": "logfall",
+      "severity": "warning",
+      "description": "Claim presents a weakened version of the opposing position without citation"
+    }
+  ],
+  "repair_suggestions": [
+    {
+      "suggestion_id": "repair_001",
+      "finding_ref": "finding_strawman_001",
+      "action": "Add citation to primary source and represent opposing position using its strongest formulation"
+    }
+  ],
+  "validation_artifact_ref": "agentplane://validation/epigov-hygiene-detector-smoke/val_strawman_001",
+  "replay_artifact_ref": "agentplane://replay/epigov-hygiene-detector-smoke/replay_strawman_001",
+  "sociosphere_protocol_ref": "protocol/epistemic-governance/v1",
+  "replay_verified": true,
+  "issued_at": "2026-06-11T10:00:00Z"
+}
diff --git a/schemas/countertest-run-artifact.schema.json b/schemas/countertest-run-artifact.schema.json
new file mode 100644
index 00000000..d3a7f34f
--- /dev/null
+++ b/schemas/countertest-run-artifact.schema.json
@@ -0,0 +1,80 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://socioprophet.io/schemas/agentplane/countertest-run-artifact/v0.1",
+  "title": "CountertestRunArtifact",
+  "description": "AgentPlane run artifact for epistemic counter-test runs (CTEST.STEELMAN.CONFIRM.V2 and variants). Confirms or refutes hygiene findings by constructing the strongest plausible counter-claim.",
+  "type": "object",
+  "required": [
+    "kind",
+    "artifact_id",
+    "run_ref",
+    "countertest_id",
+    "hygiene_run_ref",
+    "input_hash",
+    "ruleset_hash",
+    "findings_addressed",
+    "countertest_outcomes",
+    "validation_artifact_ref",
+    "replay_artifact_ref",
+    "sociosphere_protocol_ref",
+    "issued_at"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "kind": { "type": "string", "const": "CountertestRunArtifact" },
+    "artifact_id": { "type": "string", "minLength": 1 },
+    "run_ref": { "type": "string", "minLength": 1 },
+    "countertest_id": {
+      "type": "string",
+      "description": "Counter-test identifier, e.g. CTEST.STEELMAN.CONFIRM.V2"
+    },
+    "hygiene_run_ref": {
+      "type": "string",
+      "description": "Reference to the HygieneRunArtifact this counter-test addresses"
+    },
+    "input_hash": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$"
+    },
+    "ruleset_hash": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$"
+    },
+    "findings_addressed": { "type": "integer", "minimum": 0 },
+    "countertest_outcomes": {
+      "type": "array",
+      "items": { "$ref": "#/$defs/CountertestOutcome" }
+    },
+    "validation_artifact_ref": { "type": "string", "minLength": 1 },
+    "replay_artifact_ref": { "type": "string", "minLength": 1 },
+    "sociosphere_protocol_ref": {
+      "type": "string",
+      "const": "protocol/epistemic-governance/v1"
+    },
+    "replay_verified": { "type": "boolean" },
+    "issued_at": { "type": "string", "format": "date-time" }
+  },
+  "$defs": {
+    "CountertestOutcome": {
+      "type": "object",
+      "required": ["outcome_id", "finding_ref", "verdict", "steelman_claim"],
+      "additionalProperties": false,
+      "properties": {
+        "outcome_id": { "type": "string", "minLength": 1 },
+        "finding_ref": { "type": "string", "minLength": 1 },
+        "verdict": {
+          "type": "string",
+          "enum": ["confirmed_finding", "refuted_finding", "inconclusive", "escalate_review"]
+        },
+        "steelman_claim": {
+          "type": "string",
+          "description": "Strongest plausible counter-claim against the hygiene finding"
+        },
+        "counter_evidence_refs": {
+          "type": "array",
+          "items": { "type": "string" }
+        }
+      }
+    }
+  }
+}
diff --git a/schemas/hygiene-run-artifact.schema.json b/schemas/hygiene-run-artifact.schema.json
new file mode 100644
index 00000000..0340f16a
--- /dev/null
+++ b/schemas/hygiene-run-artifact.schema.json
@@ -0,0 +1,93 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://socioprophet.io/schemas/agentplane/hygiene-run-artifact/v0.1",
+  "title": "HygieneRunArtifact",
+  "description": "AgentPlane run artifact for epistemic hygiene detector runs (LOGFALL.STRAWMAN.V2 and variants). Deterministic: same input + same ruleset hash must produce same output.",
+  "type": "object",
+  "required": [
+    "kind",
+    "artifact_id",
+    "run_ref",
+    "detector_id",
+    "ruleset_hash",
+    "input_hash",
+    "claims_evaluated",
+    "hygiene_findings",
+    "validation_artifact_ref",
+    "replay_artifact_ref",
+    "sociosphere_protocol_ref",
+    "issued_at"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "kind": { "type": "string", "const": "HygieneRunArtifact" },
+    "artifact_id": { "type": "string", "minLength": 1 },
+    "run_ref": { "type": "string", "minLength": 1 },
+    "detector_id": {
+      "type": "string",
+      "description": "Detector identifier, e.g. LOGFALL.STRAWMAN.V2"
+    },
+    "ruleset_hash": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$"
+    },
+    "input_hash": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$"
+    },
+    "claims_evaluated": { "type": "integer", "minimum": 0 },
+    "hygiene_findings": {
+      "type": "array",
+      "items": { "$ref": "#/$defs/HygieneFinding" }
+    },
+    "repair_suggestions": {
+      "type": "array",
+      "items": { "$ref": "#/$defs/RepairSuggestion" }
+    },
+    "validation_artifact_ref": { "type": "string", "minLength": 1 },
+    "replay_artifact_ref": { "type": "string", "minLength": 1 },
+    "sociosphere_protocol_ref": {
+      "type": "string",
+      "const": "protocol/epistemic-governance/v1"
+    },
+    "replay_verified": { "type": "boolean" },
+    "issued_at": { "type": "string", "format": "date-time" }
+  },
+  "$defs": {
+    "HygieneFinding": {
+      "type": "object",
+      "required": ["finding_id", "claim_ref", "finding_type", "severity"],
+      "additionalProperties": false,
+      "properties": {
+        "finding_id": { "type": "string", "minLength": 1 },
+        "claim_ref": { "type": "string", "minLength": 1 },
+        "finding_type": {
+          "type": "string",
+          "enum": [
+            "logfall",
+            "strawman",
+            "attribution_without_evidence",
+            "load_bearing_metaphor",
+            "missing_non_claim",
+            "circular_evidence"
+          ]
+        },
+        "severity": {
+          "type": "string",
+          "enum": ["info", "warning", "error", "critical"]
+        },
+        "description": { "type": "string" }
+      }
+    },
+    "RepairSuggestion": {
+      "type": "object",
+      "required": ["suggestion_id", "finding_ref", "action"],
+      "additionalProperties": false,
+      "properties": {
+        "suggestion_id": { "type": "string", "minLength": 1 },
+        "finding_ref": { "type": "string", "minLength": 1 },
+        "action": { "type": "string", "minLength": 1 }
+      }
+    }
+  }
+}
diff --git a/tools/validate_epigov_artifacts.py b/tools/validate_epigov_artifacts.py
new file mode 100644
index 00000000..5be79c7f
--- /dev/null
+++ b/tools/validate_epigov_artifacts.py
@@ -0,0 +1,126 @@
+#!/usr/bin/env python3
+"""Validate Epistemic Governance bundle artifacts.
+
+Checks HygieneRunArtifact and CountertestRunArtifact schema conformance.
+Policy gates:
+- sociosphere_protocol_ref must be protocol/epistemic-governance/v1
+- ruleset_hash and input_hash must match sha256:<64-hex>
+- Tampered input (replay_verified=false) must fail
+- CountertestRunArtifact must reference a hygiene_run_ref
+"""
+from __future__ import annotations
+
+import json
+import re
+import sys
+from pathlib import Path
+
+try:
+    import jsonschema
+except ImportError:
+    print("ERROR: jsonschema not installed", file=sys.stderr)
+    sys.exit(1)
+
+ROOT = Path(__file__).resolve().parent.parent
+HYGIENE_SCHEMA = json.loads(
+    (ROOT / "schemas" / "hygiene-run-artifact.schema.json").read_text()
+)
+COUNTERTEST_SCHEMA = json.loads(
+    (ROOT / "schemas" / "countertest-run-artifact.schema.json").read_text()
+)
+
+HASH_RE = re.compile(r"^sha256:[A-Fa-f0-9]{64}$")
+EPIGOV_PROTOCOL = "protocol/epistemic-governance/v1"
+
+EXAMPLE_PATHS = [
+    ROOT / "examples" / "receipts" / "epigov-strawman-smoke" / "hygiene-run-artifact.example.json",
+    ROOT / "examples" / "receipts" / "epigov-strawman-smoke" / "countertest-run-artifact.example.json",
+]
+
+errors: list[str] = []
+results: list[bool] = []
+
+
+def ok(label: str) -> None:
+    print(f"PASS {label}")
+    results.append(True)
+
+
+def fail(label: str, reason: str) -> None:
+    errors.append(f"FAIL {label}: {reason}")
+    results.append(False)
+
+
+def detect_schema(data: dict) -> tuple[str, dict] | None:
+    kind = data.get("kind")
+    if kind == "HygieneRunArtifact":
+        return kind, HYGIENE_SCHEMA
+    if kind == "CountertestRunArtifact":
+        return kind, COUNTERTEST_SCHEMA
+    return None
+
+
+def policy_gate_errors(data: dict, kind: str) -> list[str]:
+    errs = []
+    proto = data.get("sociosphere_protocol_ref", "")
+    if proto != EPIGOV_PROTOCOL:
+        errs.append(f"sociosphere_protocol_ref must be {EPIGOV_PROTOCOL!r}, got {proto!r}")
+    for field in ("ruleset_hash", "input_hash"):
+        v = data.get(field, "")
+        if v and not HASH_RE.match(v):
+            errs.append(f"{field} must match sha256:<64-hex>")
+    if data.get("replay_verified") is False:
+        errs.append("replay_verified=false — tampered input detected; run artifact is invalid")
+    if kind == "CountertestRunArtifact" and not data.get("hygiene_run_ref"):
+        errs.append("CountertestRunArtifact requires hygiene_run_ref")
+    return errs
+
+
+for path in EXAMPLE_PATHS:
+    label = path.name
+    try:
+        data = json.loads(path.read_text())
+    except (json.JSONDecodeError, FileNotFoundError) as e:
+        fail(f"load {label}", str(e))
+        continue
+
+    ok(f"json-load {label}")
+
+    detected = detect_schema(data)
+    if detected is None:
+        fail(f"kind {label}", "unknown artifact kind")
+        continue
+
+    kind, schema = detected
+    v = jsonschema.Draft202012Validator(schema)
+    schema_errs = list(v.iter_errors(data))
+    policy_errs = policy_gate_errors(data, kind)
+
+    for e in schema_errs:
+        fail(f"schema {label}", e.message)
+    for e in policy_errs:
+        fail(f"policy-gate {label}", e)
+    if not schema_errs and not policy_errs:
+        ok(f"valid {label} ({kind})")
+
+# Also validate bundle.json files parse as valid JSON
+for bundle_dir in ["epigov-hygiene-detector-smoke", "epigov-countertest-smoke", "epigov-policy-backtest"]:
+    bundle_path = ROOT / "bundles" / bundle_dir / "bundle.json"
+    try:
+        data = json.loads(bundle_path.read_text())
+        if data.get("kind") != "Bundle":
+            fail(f"bundle-kind {bundle_dir}", "kind must be Bundle")
+        else:
+            ok(f"bundle-json {bundle_dir}")
+    except (json.JSONDecodeError, FileNotFoundError) as e:
+        fail(f"bundle-load {bundle_dir}", str(e))
+
+passed = sum(results)
+if errors:
+    print(file=sys.stderr)
+    for e in errors:
+        print(e, file=sys.stderr)
+    print(f"\n{passed} passed, {len(errors)} failed", file=sys.stderr)
+    sys.exit(1)
+
+print(f"\n{passed} epigov-artifacts checks passed")