diff --git a/missionledger/__init__.py b/missionledger/__init__.py
index c6a5337..b3cc4a1 100644
--- a/missionledger/__init__.py
+++ b/missionledger/__init__.py
@@ -6,7 +6,7 @@ and Safety/Privacy contracts, a shadow planner, a simple on-device safety proof
 hook, and a tamper-evident governance ledger.
 """
 
-from .dsl import LocalProblem, SafetyContracts, PrivacyContracts, PlanDelta
+from .dsl import LocalProblem, SafetyContracts, PrivacyContracts, PlanDelta, PoeticCert, ReplayBundle
 from .planner import ShadowPlanner, PlanResult
 from .safety import verify_plan
 from .governance import GovernanceLedger
@@ -16,6 +16,8 @@ __all__ = [
     "SafetyContracts",
     "PrivacyContracts",
     "PlanDelta",
+    "PoeticCert",
+    "ReplayBundle",
     "ShadowPlanner",
     "PlanResult",
     "verify_plan",
diff --git a/missionledger/dsl.py b/missionledger/dsl.py
index ad0debb..f2c0b8e 100644
--- a/missionledger/dsl.py
+++ b/missionledger/dsl.py
@@ -47,3 +47,36 @@ class PlanDelta:
     delta: Dict[str, Any] = field(default_factory=dict)
     version: int = 0
     metadata: Dict[str, Any] = field(default_factory=dict)
+
+
+
+@dataclass
+class PoeticCert:
+    """Compact human+machine verifiable certificate for quick triage.
+
+    - invariants: key safety/resource invariants (collision, energy envelopes)
+    - summary: short natural-language summary for on-call triage
+    - issued_by: identifier of the issuer (device or service)
+    - timestamp: optional ISO timestamp string
+    """
+
+    invariants: Dict[str, Any] = field(default_factory=dict)
+    summary: str = ""
+    issued_by: str = ""
+    timestamp: str = ""
+
+
+@dataclass
+class ReplayBundle:
+    """Signed, Merkle-linked plan trace bundle used for deterministic replay.
+
+    - entries: list of logged entries (dicts)
+    - signer: identifier of signer
+    - merkle_root: compact hex digest representing the bundle contents
+    - nonce: optional replay nonce
+    """
+
+    entries: List[Dict[str, Any]] = field(default_factory=list)
+    signer: str = ""
+    merkle_root: str = ""
+    nonce: str = ""
diff --git a/missionledger/governance.py b/missionledger/governance.py
index 6513ee1..034ed54 100644
--- a/missionledger/governance.py
+++ b/missionledger/governance.py
@@ -4,6 +4,10 @@ import hashlib
 import json
 from datetime import datetime
 from typing import List
+from typing import Tuple
+import json
+
+from .dsl import PoeticCert, ReplayBundle
 
 
 class GovernanceLedger:
@@ -30,6 +34,41 @@ class GovernanceLedger:
         self._head_hash = hashlib.sha256(json.dumps(payload, sort_keys=True).encode()).hexdigest()
         self._entries.append(payload)
 
+    def emit_poetic_cert(self, invariants: dict, summary: str, issuer: str) -> PoeticCert:
+        """Emit a compact PoeticCert for quick triage and machine checks.
+
+        This is intentionally minimal and human-readable while remaining
+        machine-checkable.
+        """
+        timestamp = datetime.utcnow().isoformat() + "Z"
+        cert = PoeticCert(invariants=invariants, summary=summary, issued_by=issuer, timestamp=timestamp)
+        # Also log the issuance to the ledger for auditability
+        self.log({"type": "poetic_cert_issued", "cert_summary": summary, "issued_by": issuer})
+        return cert
+
+    def create_replay_bundle(self, entries: List[dict], signer: str, nonce: str = "") -> ReplayBundle:
+        """Construct a ReplayBundle with a compact merkle-style root.
+
+        For the MVP we compute a deterministic root by hashing each entry and
+        then hashing the concatenation of sorted entry hashes. This produces a
+        compact fingerprint suitable for off-device anchoring.
+        """
+        # Normalize and hash entries deterministically
+        entry_hashes = []
+        for e in entries:
+            h = hashlib.sha256(json.dumps(e, sort_keys=True).encode()).hexdigest()
+            entry_hashes.append(h)
+
+        # deterministic ordering
+        entry_hashes.sort()
+        concat = "".join(entry_hashes).encode()
+        merkle_root = hashlib.sha256(concat).hexdigest() if concat else ""
+
+        bundle = ReplayBundle(entries=list(entries), signer=signer, merkle_root=merkle_root, nonce=nonce)
+        # log bundle creation
+        self.log({"type": "replay_bundle_created", "signer": signer, "merkle_root": merkle_root})
+        return bundle
+
     @property
     def entries(self) -> List[dict]:
         return self._entries[:]
diff --git a/tests/test_cert_and_replay.py b/tests/test_cert_and_replay.py
new file mode 100644
index 0000000..8367cc1
--- /dev/null
+++ b/tests/test_cert_and_replay.py
@@ -0,0 +1,23 @@
+from missionledger.governance import GovernanceLedger
+
+
+def test_poetic_cert_and_replay_bundle_creation():
+    gl = GovernanceLedger(device_id="test-device-2")
+
+    invariants = {"collision_envelope": 1.2, "energy_budget": 42}
+    cert = gl.emit_poetic_cert(invariants=invariants, summary="Safe envelope OK", issuer="planner-v1")
+
+    assert cert.issued_by == "planner-v1"
+    assert "collision_envelope" in cert.invariants
+
+    entries = [
+        {"event": "plan_step", "step": 1},
+        {"event": "plan_step", "step": 2},
+    ]
+    bundle = gl.create_replay_bundle(entries=entries, signer="device-A", nonce="n-123")
+
+    assert bundle.signer == "device-A"
+    assert bundle.merkle_root != ""
+    assert len(bundle.entries) == 2
+    # ensure ledger recorded the bundle creation as an entry
+    assert any(e.get("entry", {}).get("type") == "replay_bundle_created" for e in gl.entries)