diff --git a/src/whitehat_security/cli.py b/src/whitehat_security/cli.py
index 3a50d4c..9053169 100644
--- a/src/whitehat_security/cli.py
+++ b/src/whitehat_security/cli.py
@@ -92,7 +92,10 @@ def main(argv: list[str] | None = None) -> None:
     admit_plane.add_argument("engagement")
     admit_plane.add_argument("registration")
     admit_plane.add_argument("--receipt", help="value-safe custody projection receipt")
-    admit_plane.add_argument("--contract", help="WP-0025 projection contract bound to the receipt")
+    admit_plane.add_argument(
+        "--contract",
+        help="WP-0025 projection contract; required for railiance.custody-projection-receipt",
+    )
     commands.add_parser("kill-switch")
     deliver = commands.add_parser("deliver")
     deliver.add_argument("report")
diff --git a/src/whitehat_security/plane.py b/src/whitehat_security/plane.py
index 1720f2d..ef1d3a8 100644
--- a/src/whitehat_security/plane.py
+++ b/src/whitehat_security/plane.py
@@ -106,8 +106,8 @@ class IdentityHandle:
 
 
 class CredentialBroker(Protocol):
-    def project(self, engagement: Engagement, registration: dict[str, Any]
-                ) -> tuple[IdentityHandle, ...]:
+    def project(self, engagement: Engagement, registration: dict[str, Any],
+                now: datetime | None = None) -> tuple[IdentityHandle, ...]:
         ...
 
     def revoke(self, lease_id: str) -> None:
@@ -148,8 +148,8 @@ class ReceiptBroker:
     def load(cls, path: str | Path) -> "ReceiptBroker":
         return cls(json.loads(Path(path).read_text(encoding="utf-8")))
 
-    def project(self, engagement: Engagement, registration: dict[str, Any]
-                ) -> tuple[IdentityHandle, ...]:
+    def project(self, engagement: Engagement, registration: dict[str, Any],
+                now: datetime | None = None) -> tuple[IdentityHandle, ...]:
         if self.receipt.get("engagement_id") != engagement.raw["engagement_id"]:
             raise AuthorizationError("projection receipt engagement_id does not match")
         if not self.receipt.get("target_ready"):
@@ -160,7 +160,8 @@ class ReceiptBroker:
         expiry = datetime.fromisoformat(str(expires_at).replace("Z", "+00:00"))
         if expiry.tzinfo is None:
             raise AuthorizationError("projection receipt expiry must include a timezone")
-        if datetime.now(UTC) > expiry.astimezone(UTC):
+        clock = (now or datetime.now(UTC)).astimezone(UTC)
+        if clock > expiry.astimezone(UTC):
             raise AuthorizationError("projection receipt has expired")
         keys = list(self.receipt.get("mounted_keys") or [])
         count = int(registration["identities"]["count"])
@@ -193,8 +194,8 @@ class ReceiptBroker:
 class UnconnectedCustodyBroker:
     """Fail-closed live broker. It never requests or returns credential values."""
 
-    def project(self, engagement: Engagement, registration: dict[str, Any]
-                ) -> tuple[IdentityHandle, ...]:
+    def project(self, engagement: Engagement, registration: dict[str, Any],
+                now: datetime | None = None) -> tuple[IdentityHandle, ...]:
         raise AuthorizationError(
             "live custody broker is not connected; no credential was requested"
         )
@@ -212,14 +213,15 @@ class LocalBroker:
         self._secrets: dict[str, bytes] = {}
         self._leases: dict[str, tuple[str, str]] = {}
 
-    def project(self, engagement: Engagement, registration: dict[str, Any]
-                ) -> tuple[IdentityHandle, ...]:
+    def project(self, engagement: Engagement, registration: dict[str, Any],
+                now: datetime | None = None) -> tuple[IdentityHandle, ...]:
         if registration.get("applicability") != "applicable":
             raise AuthorizationError("broker will not project identities for a non-applicable target")
         count = int(registration["identities"]["count"])
         lease_id = os.urandom(8).hex()
         ttl = min(int(engagement.raw["credential_max_ttl_seconds"]), STANDING_E2_TTL)
-        expires_at = (datetime.now(UTC) + timedelta(seconds=ttl)).isoformat().replace("+00:00", "Z")
+        clock = (now or datetime.now(UTC)).astimezone(UTC)
+        expires_at = (clock + timedelta(seconds=ttl)).isoformat().replace("+00:00", "Z")
         handles: list[IdentityHandle] = []
         if count >= 1:
             role = "owner" if count == 2 else "runtime"
@@ -302,7 +304,7 @@ def admit(*, engagement: Engagement, registration: dict[str, Any],
     selected = broker or default_broker(engagement)
     count = int(registration["identities"]["count"])
     if count:
-        identities = selected.project(engagement, registration)
+        identities = selected.project(engagement, registration, now=now)
         if len(identities) != count:
             raise AuthorizationError(f"broker must project exactly {count} identities")
         expected = {2: {"owner", "attacker"}, 1: {"runtime"}}[count]
@@ -313,7 +315,7 @@ def admit(*, engagement: Engagement, registration: dict[str, Any],
         lease_id = identities[0].lease_id
     else:
         if approval_class not in FIXTURE_CLASSES:
-            selected.project(engagement, registration)
+            selected.project(engagement, registration, now=now)
         identities = ()
         lease_id = os.urandom(8).hex()
         if hasattr(selected, "_leases"):
diff --git a/src/whitehat_security/platform_custody.py b/src/whitehat_security/platform_custody.py
index df1d00d..2f3347c 100644
--- a/src/whitehat_security/platform_custody.py
+++ b/src/whitehat_security/platform_custody.py
@@ -2,8 +2,10 @@
 
 from __future__ import annotations
 
+import hashlib
 import json
 import os
+import re
 from datetime import UTC, datetime
 from pathlib import Path
 from typing import Any
@@ -15,6 +17,8 @@ CONTRACT_INTERFACE = "railiance.custody-projection-contract"
 BROKER_INTERFACE = "railiance.custody-broker-readiness"
 PROJECTION_INTERFACE = "railiance.custody-projection-receipt"
 CLEANUP_INTERFACE = "railiance.custody-cleanup-receipt"
+WORKPLAN_ID = "RAILIANCE-WP-0025"
+BROKER_OWNER = "whitehat-security"
 SCHEMA_FILES = (
     "custody-projection-contract.schema.json",
     "custody-broker-readiness.schema.json",
@@ -25,6 +29,12 @@ FORBIDDEN_KEYS = {
     "token", "tokens", "password", "secret_value", "secret_values",
     "bearer", "private_key", "credential",
 }
+SHA256 = re.compile(r"(?:sha256:)?[0-9a-f]{64}\Z")
+GIT_REVISION = re.compile(r"[0-9a-f]{40}\Z")
+DNS_LABEL = re.compile(r"[a-z0-9](?:[-a-z0-9]{0,61}[a-z0-9])?\Z")
+LEASE_ID = re.compile(r"custody:[0-9a-f]{32}\Z")
+RECEIPT_ID = re.compile(r"sha256:[0-9a-f]{64}\Z")
+ENGAGEMENT_ID = re.compile(r"[A-Z0-9][A-Z0-9._-]{7,127}\Z")
 
 
 def schema_dir() -> Path:
@@ -54,6 +64,41 @@ def load_schemas() -> dict[str, dict[str, Any]]:
     return loaded
 
 
+def canonical_json(value: Any) -> str:
+    return json.dumps(value, sort_keys=True, separators=(",", ":"), ensure_ascii=True)
+
+
+def digest(value: Any) -> str:
+    return hashlib.sha256(canonical_json(value).encode("utf-8")).hexdigest()
+
+
+def file_digest(path: Path) -> str:
+    result = hashlib.sha256()
+    with path.open("rb") as handle:
+        for block in iter(lambda: handle.read(1024 * 1024), b""):
+            result.update(block)
+    return result.hexdigest()
+
+
+def interface_artifacts() -> dict[str, str]:
+    root = schema_dir()
+    return {f"schemas/{name}": file_digest(root / name) for name in SCHEMA_FILES}
+
+
+def resource_suffix(engagement_id: str) -> str:
+    return hashlib.sha256(engagement_id.encode("utf-8")).hexdigest()[:12]
+
+
+def resource_names(contract: dict[str, Any]) -> dict[str, str]:
+    suffix = resource_suffix(contract["engagement_id"])
+    return {
+        "policy": f"custody-{suffix}",
+        "role": f"custody-{suffix}",
+        "store": f"custody-{suffix}",
+        "external_secret": contract["runner"]["secret_name"],
+    }
+
+
 def _assert_value_safe(value: Any) -> None:
     if isinstance(value, dict):
         for key, child in value.items():
@@ -65,10 +110,18 @@ def _assert_value_safe(value: Any) -> None:
             _assert_value_safe(child)
 
 
-def _require(document: dict[str, Any], key: str) -> Any:
-    if key not in document:
-        raise AuthorizationError(f"custody document missing {key}")
-    return document[key]
+def _require_string(value: dict[str, Any], key: str) -> str:
+    observed = value.get(key)
+    if not isinstance(observed, str) or not observed:
+        raise AuthorizationError(f"{key} must be a non-empty string")
+    return observed
+
+
+def _require_sha(value: dict[str, Any], key: str) -> str:
+    observed = _require_string(value, key)
+    if not SHA256.fullmatch(observed):
+        raise AuthorizationError(f"{key} must be a SHA-256 digest")
+    return observed.removeprefix("sha256:")
 
 
 def _timestamp(value: Any, field: str) -> datetime:
@@ -83,79 +136,254 @@ def _timestamp(value: Any, field: str) -> datetime:
     return parsed.astimezone(UTC)
 
 
+def contract_digest(contract: dict[str, Any]) -> str:
+    validate_projection_contract(contract)
+    return digest(contract)
+
+
 def validate_projection_contract(document: dict[str, Any]) -> dict[str, Any]:
     _assert_value_safe(document)
     if document.get("interface") != CONTRACT_INTERFACE or document.get("version") != 1:
         raise AuthorizationError("unsupported projection contract")
+    if document.get("workplan_id") != WORKPLAN_ID:
+        raise AuthorizationError("projection contract has the wrong workplan")
+    engagement_id = _require_string(document, "engagement_id")
+    if not ENGAGEMENT_ID.fullmatch(engagement_id):
+        raise AuthorizationError("engagement_id has an invalid shape")
     if document.get("status") != "approved":
         raise AuthorizationError("projection contract is not approved")
+
+    target = document.get("target")
+    runner = document.get("runner")
+    window = document.get("window")
+    authority = document.get("authority")
     identities = document.get("identities")
+    if not all(isinstance(item, dict) for item in (target, runner, window, authority)):
+        raise AuthorizationError("target, runner, window and authority must be objects")
     if not isinstance(identities, list) or len(identities) != 2:
         raise AuthorizationError("projection contract must name two identities")
-    roles = {item.get("role") for item in identities if isinstance(item, dict)}
-    handles = {item.get("handle") for item in identities if isinstance(item, dict)}
-    if roles != {"attacker", "owner"} or handles != {"token-a", "token-b"}:
+
+    target_id = _require_string(target, "id")
+    target_namespace = _require_string(target, "namespace")
+    target_deployment = _require_string(target, "deployment")
+    _require_string(target, "container")
+    _require_string(target, "sender_external_secret")
+    if not DNS_LABEL.fullmatch(target_namespace) or not DNS_LABEL.fullmatch(target_deployment):
+        raise AuthorizationError("target namespace and deployment must be DNS labels")
+    revision = _require_string(target, "revision")
+    if not GIT_REVISION.fullmatch(revision):
+        raise AuthorizationError("target.revision must be a full Git revision")
+    image = _require_string(target, "image_digest")
+    if not re.fullmatch(r"sha256:[0-9a-f]{64}", image):
+        raise AuthorizationError("target.image_digest must be a SHA-256 image digest")
+    _require_sha(target, "contract_sha256")
+    _require_sha(runner, "manifest_sha256")
+    _require_sha(document, "engagement_contract_sha256")
+
+    namespace = _require_string(runner, "namespace")
+    secret_name = _require_string(runner, "secret_name")
+    _require_string(runner, "service_account")
+    mount_root = _require_string(runner, "mount_root").rstrip("/")
+    if not DNS_LABEL.fullmatch(namespace) or not DNS_LABEL.fullmatch(secret_name):
+        raise AuthorizationError("runner namespace and secret_name must be DNS labels")
+    if not mount_root.startswith("/") or ".." in Path(mount_root).parts:
+        raise AuthorizationError("runner.mount_root must be an absolute safe path")
+
+    starts = _timestamp(window.get("starts_at"), "window.starts_at")
+    cutoff = _timestamp(window.get("projection_cutoff"), "window.projection_cutoff")
+    expires = _timestamp(window.get("expires_at"), "window.expires_at")
+    if not starts < cutoff < expires:
+        raise AuthorizationError("window must satisfy starts_at < projection_cutoff < expires_at")
+    if (expires - starts).total_seconds() > 900:
+        raise AuthorizationError("ephemeral custody window may not exceed 900 seconds")
+
+    remote = _require_string(authority, "remote")
+    if any(character.isspace() for character in remote):
+        raise AuthorizationError("authority.remote must be one SSH destination")
+    registry_path = _require_string(authority, "registry_path")
+    registry_field = _require_string(authority, "registry_field")
+    kv_mount = _require_string(authority, "kv_mount")
+    kv_prefix = _require_string(authority, "kv_prefix").strip("/")
+    _require_string(authority, "eso_service_account")
+    _require_string(authority, "eso_namespace")
+    if engagement_id not in kv_prefix or target_id not in kv_prefix:
+        raise AuthorizationError("authority.kv_prefix must bind engagement_id and target id")
+    if "/" in kv_mount or not registry_path or "/" in registry_field:
+        raise AuthorizationError("invalid KV mount or registry field")
+
+    handles: set[str] = set()
+    roles: set[str] = set()
+    senders: set[str] = set()
+    tenants: set[str] = set()
+    for identity in identities:
+        if not isinstance(identity, dict):
+            raise AuthorizationError("identity entries must be objects")
+        handle = _require_string(identity, "handle")
+        role = _require_string(identity, "role")
+        sender = _require_string(identity, "sender_name")
+        tenant = _require_string(identity, "tenant")
+        mount_path = _require_string(identity, "mount_path")
+        if identity.get("may_read") is not True or identity.get("may_write") is not True:
+            raise AuthorizationError("temporary identities require may_read and may_write")
+        if mount_path != f"{mount_root}/{handle}":
+            raise AuthorizationError("identity mount_path must be mount_root plus its handle")
+        handles.add(handle)
+        roles.add(role)
+        senders.add(sender)
+        tenants.add(tenant)
+    if handles != {"token-a", "token-b"} or roles != {"attacker", "owner"}:
         raise AuthorizationError("projection contract identities are not attacker/owner token-a/token-b")
+    if len(senders) != 2 or len(tenants) != 2:
+        raise AuthorizationError("sender names and tenants must be distinct")
+    names = resource_names(document)
+    if any(not DNS_LABEL.fullmatch(name) for name in names.values()):
+        raise AuthorizationError("derived resource name is not a DNS label")
     return document
 
 
 def validate_projection_receipt(
-    document: dict[str, Any], *, contract: dict[str, Any] | None = None
+    document: dict[str, Any], *, contract: dict[str, Any]
 ) -> dict[str, Any]:
+    validate_projection_contract(contract)
     _assert_value_safe(document)
     if document.get("interface") != PROJECTION_INTERFACE or document.get("version") != 1:
         raise AuthorizationError("unsupported projection receipt")
-    if document.get("state") != "projected":
+    if document.get("workplan_id") != WORKPLAN_ID or document.get("state") != "projected":
         raise AuthorizationError("projection receipt is not in projected state")
+    if document.get("engagement_id") != contract["engagement_id"]:
+        raise AuthorizationError("projection receipt engagement_id does not match contract")
+    if document.get("projection_contract_digest") != contract_digest(contract):
+        raise AuthorizationError("projection receipt contract digest does not match contract")
+    expected_target = {
+        "id": contract["target"]["id"],
+        "revision": contract["target"]["revision"],
+        "image_digest": contract["target"]["image_digest"],
+    }
+    if document.get("target") != expected_target:
+        raise AuthorizationError("projection receipt target does not match contract")
+    lease_id = document.get("lease_id")
+    if not isinstance(lease_id, str) or not LEASE_ID.fullmatch(lease_id):
+        raise AuthorizationError("projection receipt lease_id is invalid")
+    broker_digest = document.get("broker_receipt_digest")
+    if not isinstance(broker_digest, str) or not re.fullmatch(r"[0-9a-f]{64}", broker_digest):
+        raise AuthorizationError("projection receipt broker digest is invalid")
     if document.get("secret_values_observed") is not False:
         raise AuthorizationError("projection receipt did not prove secret values were unobserved")
     if document.get("cleanup_authority") != "railiance-platform":
         raise AuthorizationError("cleanup authority must be railiance-platform")
-    lease_id = _require(document, "lease_id")
-    if not isinstance(lease_id, str) or not lease_id.startswith("custody:"):
-        raise AuthorizationError("projection receipt lease_id is invalid")
+    projected = _timestamp(document.get("projected_at"), "projected_at")
+    expires = _timestamp(document.get("expires_at"), "expires_at")
+    contract_expires = _timestamp(contract["window"]["expires_at"], "window.expires_at")
+    if expires != contract_expires or projected >= expires:
+        raise AuthorizationError("projection receipt has invalid projection/expiry times")
     identities = document.get("identities")
-    if not isinstance(identities, list) or len(identities) != 2:
-        raise AuthorizationError("projection receipt must name two identities")
-    roles = {item.get("role") for item in identities if isinstance(item, dict)}
-    if roles != {"attacker", "owner"}:
-        raise AuthorizationError("projection receipt must include attacker and owner")
-    if contract is not None:
-        validate_projection_contract(contract)
-        if document.get("engagement_id") != contract["engagement_id"]:
-            raise AuthorizationError("projection receipt engagement_id does not match contract")
+    expected_identities = sorted(
+        (
+            {
+                "handle": item["handle"],
+                "role": item["role"],
+                "sender_name": item["sender_name"],
+                "mount_path": item["mount_path"],
+            }
+            for item in contract["identities"]
+        ),
+        key=lambda item: item["handle"],
+    )
+    if identities != expected_identities:
+        raise AuthorizationError("projection receipt identities do not match contract")
+    resources = document.get("resources")
+    if not isinstance(resources, dict) or resources.get("names") != resource_names(contract):
+        raise AuthorizationError("projection receipt resources do not match contract")
+    uids = resources.get("uids")
+    if not isinstance(uids, dict) or set(uids) != {"store", "external_secret", "mounted_secret"}:
+        raise AuthorizationError("projection receipt requires exact Kubernetes UIDs")
+    if any(not isinstance(uid, str) or not uid for uid in uids.values()):
+        raise AuthorizationError("projection receipt contains an invalid Kubernetes UID")
+    base = dict(document)
+    observed_id = base.pop("receipt_id", None)
+    if not isinstance(observed_id, str) or not RECEIPT_ID.fullmatch(observed_id):
+        raise AuthorizationError("projection receipt_id is invalid")
+    if observed_id != f"sha256:{digest(base)}":
+        raise AuthorizationError("projection receipt_id is not the canonical content digest")
     return document
 
 
 def validate_cleanup_receipt(
-    document: dict[str, Any], *, projection: dict[str, Any]
+    document: dict[str, Any], *, projection: dict[str, Any], contract: dict[str, Any]
 ) -> dict[str, Any]:
+    validate_projection_receipt(projection, contract=contract)
     _assert_value_safe(document)
     if document.get("interface") != CLEANUP_INTERFACE or document.get("version") != 1:
         raise AuthorizationError("unsupported cleanup receipt")
-    if document.get("state") != "cleaned":
+    if document.get("workplan_id") != WORKPLAN_ID or document.get("state") != "cleaned":
         raise AuthorizationError("cleanup receipt is not in cleaned state")
-    if document.get("secret_values_observed") is not False:
-        raise AuthorizationError("cleanup receipt did not prove secret values were unobserved")
+    if document.get("engagement_id") != contract["engagement_id"]:
+        raise AuthorizationError("cleanup receipt engagement_id does not match contract")
     if document.get("lease_id") != projection.get("lease_id"):
         raise AuthorizationError("cleanup receipt lease_id does not match projection")
-    if document.get("engagement_id") != projection.get("engagement_id"):
-        raise AuthorizationError("cleanup receipt engagement_id does not match projection")
     if document.get("projection_receipt_id") != projection.get("receipt_id"):
         raise AuthorizationError("cleanup receipt is not bound to this projection receipt")
+    _timestamp(document.get("cleaned_at"), "cleaned_at")
     if document.get("target_ready") is not True:
         raise AuthorizationError("cleanup receipt does not show a ready target")
+    if document.get("secret_values_observed") is not False:
+        raise AuthorizationError("cleanup receipt did not prove secret values were unobserved")
     return document
 
 
-def validate_broker_readiness(document: dict[str, Any]) -> dict[str, Any]:
+def validate_broker_readiness(
+    document: dict[str, Any], *, contract: dict[str, Any], now: datetime | None = None
+) -> dict[str, Any]:
+    validate_projection_contract(contract)
     _assert_value_safe(document)
     if document.get("interface") != BROKER_INTERFACE or document.get("version") != 1:
         raise AuthorizationError("unsupported broker readiness receipt")
-    if document.get("owner") != "whitehat-security":
+    if document.get("workplan_id") != WORKPLAN_ID or document.get("owner") != BROKER_OWNER:
         raise AuthorizationError("broker readiness owner must be whitehat-security")
+    if document.get("decision") != "approve":
+        raise AuthorizationError("broker readiness receipt is not approved")
+    if document.get("engagement_id") != contract["engagement_id"]:
+        raise AuthorizationError("broker readiness engagement does not match contract")
+    if document.get("target_id") != contract["target"]["id"]:
+        raise AuthorizationError("broker readiness target does not match contract")
+    if document.get("projection_contract_digest") != contract_digest(contract):
+        raise AuthorizationError("broker readiness contract digest does not match contract")
+    if document.get("projection_receipt_interface") != PROJECTION_INTERFACE:
+        raise AuthorizationError("broker readiness cannot consume projection receipt v1")
+    if document.get("interface_artifacts") != interface_artifacts():
+        raise AuthorizationError("broker readiness interface artifacts are stale")
+    if document.get("required_roles") != ["attacker", "owner"]:
+        raise AuthorizationError("broker readiness has the wrong identity roles")
+    expected_mounts = sorted(item["mount_path"] for item in contract["identities"])
+    if document.get("mount_paths") != expected_mounts:
+        raise AuthorizationError("broker readiness mount paths do not match contract")
+    adapter = document.get("adapter")
+    if not isinstance(adapter, dict):
+        raise AuthorizationError("broker readiness requires adapter evidence")
+    adapter_path = adapter.get("path")
+    if (
+        adapter.get("repo") != "whitehat-security"
+        or not isinstance(adapter_path, str)
+        or not adapter_path
+        or Path(adapter_path).is_absolute()
+        or ".." in Path(adapter_path).parts
+    ):
+        raise AuthorizationError("broker adapter repo/path is invalid")
+    if not GIT_REVISION.fullmatch(str(adapter.get("revision", ""))):
+        raise AuthorizationError("broker adapter revision must be a full Git revision")
+    if not SHA256.fullmatch(str(adapter.get("sha256", ""))):
+        raise AuthorizationError("broker adapter requires a SHA-256 digest")
+    if adapter.get("tests_passed") is not True or document.get("cleanup_request_supported") is not True:
+        raise AuthorizationError("broker adapter tests and cleanup support are required")
     if document.get("secret_values_observed") is not False:
         raise AuthorizationError("broker readiness receipt is not value-safe")
+    created = _timestamp(document.get("created_at"), "broker.created_at")
+    current = (now or datetime.now(UTC)).astimezone(UTC)
+    starts = _timestamp(contract["window"]["starts_at"], "window.starts_at")
+    expires = _timestamp(contract["window"]["expires_at"], "window.expires_at")
+    day_start = starts.replace(hour=0, minute=0, second=0, microsecond=0)
+    if created > current or created > expires or created < day_start:
+        raise AuthorizationError("broker receipt timestamp is outside the engagement day")
     return document
 
 
@@ -168,13 +396,27 @@ class PlatformCustodyBroker:
         self,
         receipt: dict[str, Any],
         *,
-        contract: dict[str, Any] | None = None,
+        contract: dict[str, Any],
         cleanup: dict[str, Any] | None = None,
+        broker: dict[str, Any] | None = None,
+        now: datetime | None = None,
     ) -> None:
-        self.receipt = validate_projection_receipt(receipt, contract=contract)
-        self.contract = validate_projection_contract(contract) if contract is not None else None
+        if contract is None:
+            raise AuthorizationError("WP-0025 projection receipt requires a bound contract")
+        self.contract = validate_projection_contract(contract)
+        self.receipt = validate_projection_receipt(receipt, contract=self.contract)
+        if broker is not None:
+            validated = validate_broker_readiness(broker, contract=self.contract, now=now)
+            if digest(validated) != self.receipt["broker_receipt_digest"]:
+                raise AuthorizationError("projection receipt broker digest does not match broker receipt")
+            self.broker = validated
+        else:
+            self.broker = None
         self.cleanup = (
-            validate_cleanup_receipt(cleanup, projection=self.receipt) if cleanup is not None else None
+            validate_cleanup_receipt(
+                cleanup, projection=self.receipt, contract=self.contract
+            )
+            if cleanup is not None else None
         )
 
     @classmethod
@@ -182,38 +424,45 @@ class PlatformCustodyBroker:
         cls,
         receipt_path: str | Path,
         *,
-        contract_path: str | Path | None = None,
+        contract_path: str | Path,
         cleanup_path: str | Path | None = None,
+        broker_path: str | Path | None = None,
+        now: datetime | None = None,
     ) -> "PlatformCustodyBroker":
+        if contract_path is None:
+            raise AuthorizationError("WP-0025 projection receipt requires a bound contract")
         receipt = json.loads(Path(receipt_path).read_text(encoding="utf-8"))
-        contract = (
-            json.loads(Path(contract_path).read_text(encoding="utf-8"))
-            if contract_path is not None else None
-        )
+        contract = json.loads(Path(contract_path).read_text(encoding="utf-8"))
         cleanup = (
             json.loads(Path(cleanup_path).read_text(encoding="utf-8"))
             if cleanup_path is not None else None
         )
-        return cls(receipt, contract=contract, cleanup=cleanup)
+        broker = (
+            json.loads(Path(broker_path).read_text(encoding="utf-8"))
+            if broker_path is not None else None
+        )
+        return cls(receipt, contract=contract, cleanup=cleanup, broker=broker, now=now)
 
-    def project(self, engagement: Engagement, registration: dict[str, Any]
-                ) -> tuple[IdentityHandle, ...]:
+    def project(self, engagement: Engagement, registration: dict[str, Any],
+                now: datetime | None = None) -> tuple[IdentityHandle, ...]:
         if self.receipt.get("engagement_id") != engagement.raw["engagement_id"]:
             raise AuthorizationError("projection receipt engagement_id does not match")
+        if self.receipt["target"]["id"] != engagement.raw.get("target_id"):
+            raise AuthorizationError("projection receipt target does not match engagement")
         expiry = _timestamp(self.receipt["expires_at"], "expires_at")
-        if datetime.now(UTC) > expiry:
+        clock = (now or datetime.now(UTC)).astimezone(UTC)
+        if clock > expiry:
             raise AuthorizationError("projection receipt has expired")
         count = int(registration["identities"]["count"])
         identities = self.receipt["identities"]
         if len(identities) != count:
             raise AuthorizationError("projection receipt identity count does not match registration")
         handles = []
-        for item in sorted(identities, key=lambda row: str(row.get("handle"))):
-            role = item["role"]
+        for item in identities:
             mount_path = item["mount_path"]
             if not str(mount_path).startswith("/var/run/secrets/whitehat/"):
                 raise AuthorizationError("identity mount_path is outside the whitehat mount")
-            handles.append(IdentityHandle(role, mount_path, self.receipt["lease_id"],
+            handles.append(IdentityHandle(item["role"], mount_path, self.receipt["lease_id"],
                                           self.receipt["expires_at"]))
         return tuple(handles)
 
@@ -232,6 +481,8 @@ def broker_from_receipt(
     """Select the WP-0025 adapter or the legacy value-safe receipt broker."""
     data = json.loads(Path(path).read_text(encoding="utf-8"))
     if data.get("interface") == PROJECTION_INTERFACE:
+        if contract_path is None:
+            raise AuthorizationError("WP-0025 projection receipt requires a bound contract")
         return PlatformCustodyBroker.load(path, contract_path=contract_path)
     from .plane import ReceiptBroker
     return ReceiptBroker(data)
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 3965eae..9f607cc 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -147,6 +147,23 @@ def test_example_projection_receipt_is_value_safe():
     assert broker.receipt["mounted_keys"] == ["token-a", "token-b"]
 
 
+def test_admit_plane_wp0025_receipt_requires_contract(tmp_path, capsys):
+    engagement = tmp_path / "engagement.json"
+    receipt = tmp_path / "receipt.json"
+    engagement.write_text(json.dumps(_live_e2_record()), encoding="utf-8")
+    receipt.write_text(json.dumps({
+        "interface": "railiance.custody-projection-receipt",
+        "version": 1,
+        "engagement_id": "WH-ENG-CLI-RECEIPT",
+        "secret_values_observed": False,
+    }), encoding="utf-8")
+    with pytest.raises(SystemExit) as stopped:
+        main(["admit-plane", str(engagement), "targets/audit-core-e2.json",
+              "--receipt", str(receipt)])
+    assert stopped.value.code == 2
+    assert "requires a bound contract" in capsys.readouterr().err
+
+
 def test_deliver_queues_abort_without_calling_it_target_assurance(tmp_path, capsys):
     report = json.loads(
         Path("evidence/WH-ENG-20260822-AUDIT-E2-02-abort.json").read_text(encoding="utf-8")
diff --git a/tests/test_platform_custody_adapter.py b/tests/test_platform_custody_adapter.py
index 9dfe80d..860be1f 100644
--- a/tests/test_platform_custody_adapter.py
+++ b/tests/test_platform_custody_adapter.py
@@ -1,19 +1,33 @@
+import copy
 import json
+import sys
 from datetime import UTC, datetime
+from pathlib import Path
 
 import pytest
 
 from whitehat_security.engagement import AuthorizationError, Engagement
 from whitehat_security.platform_custody import (
-    CLEANUP_INTERFACE, CONTRACT_INTERFACE, PROJECTION_INTERFACE,
-    PlatformCustodyBroker, load_schemas, validate_broker_readiness,
-    validate_cleanup_receipt, validate_projection_contract,
+    CLEANUP_INTERFACE,
+    CONTRACT_INTERFACE,
+    PROJECTION_INTERFACE,
+    PlatformCustodyBroker,
+    broker_from_receipt,
+    contract_digest,
+    digest,
+    interface_artifacts,
+    load_schemas,
+    resource_names,
+    validate_broker_readiness,
+    validate_cleanup_receipt,
+    validate_projection_contract,
     validate_projection_receipt,
 )
 from whitehat_security.plane import KillSwitch, admit
+from whitehat_security.targets import load_registration
 
 
-NOW = datetime(2026, 8, 22, 12, tzinfo=UTC)
+NOW = datetime(2026, 8, 22, 12, 2, tzinfo=UTC)
 
 
 def contract() -> dict:
@@ -44,7 +58,7 @@ def contract() -> dict:
         "window": {
             "starts_at": "2026-08-22T12:00:00Z",
             "projection_cutoff": "2026-08-22T12:03:00Z",
-            "expires_at": "2099-01-01T00:00:00Z",
+            "expires_at": "2026-08-22T12:15:00Z",
         },
         "authority": {
             "remote": "railiance01",
@@ -78,57 +92,8 @@ def contract() -> dict:
     }
 
 
-def projection_receipt() -> dict:
-    return {
-        "interface": PROJECTION_INTERFACE,
-        "version": 1,
-        "workplan_id": "RAILIANCE-WP-0025",
-        "state": "projected",
-        "receipt_id": "sha256:" + "e" * 64,
-        "lease_id": "custody:" + "f" * 32,
-        "engagement_id": "WH-ENG-FIXTURE-1",
-        "target": {"id": "audit-core", "revision": "a" * 40, "image_digest": "sha256:" + "b" * 64},
-        "projection_contract_digest": "1" * 64,
-        "broker_receipt_digest": "2" * 64,
-        "projected_at": "2026-08-22T12:02:00Z",
-        "expires_at": "2099-01-01T00:00:00Z",
-        "identities": [
-            {
-                "handle": "token-a",
-                "role": "attacker",
-                "sender_name": "whitehat-e2-a",
-                "mount_path": "/var/run/secrets/whitehat/token-a",
-            },
-            {
-                "handle": "token-b",
-                "role": "owner",
-                "sender_name": "whitehat-e2-b",
-                "mount_path": "/var/run/secrets/whitehat/token-b",
-            },
-        ],
-        "resources": {"names": {"store": "custody-example"}, "uids": {"mounted_secret": "uid"}},
-        "cleanup_authority": "railiance-platform",
-        "secret_values_observed": False,
-    }
-
-
-def cleanup_receipt() -> dict:
-    return {
-        "interface": CLEANUP_INTERFACE,
-        "version": 1,
-        "workplan_id": "RAILIANCE-WP-0025",
-        "state": "cleaned",
-        "lease_id": "custody:" + "f" * 32,
-        "engagement_id": "WH-ENG-FIXTURE-1",
-        "projection_receipt_id": "sha256:" + "e" * 64,
-        "cleaned_at": "2026-08-22T12:14:00Z",
-        "removed_resources": ["custody-example"],
-        "target_ready": True,
-        "secret_values_observed": False,
-    }
-
-
-def broker_readiness() -> dict:
+def broker_readiness(bound: dict | None = None) -> dict:
+    bound = bound or contract()
     return {
         "interface": "railiance.custody-broker-readiness",
         "version": 1,
@@ -137,21 +102,13 @@ def broker_readiness() -> dict:
         "reviewer": "whitehat-owner",
         "decision": "approve",
         "created_at": "2026-08-22T12:00:00Z",
-        "engagement_id": "WH-ENG-FIXTURE-1",
-        "target_id": "audit-core",
-        "projection_contract_digest": "1" * 64,
+        "engagement_id": bound["engagement_id"],
+        "target_id": bound["target"]["id"],
+        "projection_contract_digest": contract_digest(bound),
         "projection_receipt_interface": PROJECTION_INTERFACE,
-        "interface_artifacts": {
-            "schemas/custody-projection-contract.schema.json": "a" * 64,
-            "schemas/custody-broker-readiness.schema.json": "b" * 64,
-            "schemas/custody-projection-receipt.schema.json": "c" * 64,
-            "schemas/custody-cleanup-receipt.schema.json": "d" * 64,
-        },
+        "interface_artifacts": interface_artifacts(),
         "required_roles": ["attacker", "owner"],
-        "mount_paths": [
-            "/var/run/secrets/whitehat/token-a",
-            "/var/run/secrets/whitehat/token-b",
-        ],
+        "mount_paths": sorted(item["mount_path"] for item in bound["identities"]),
         "adapter": {
             "repo": "whitehat-security",
             "revision": "a" * 40,
@@ -164,11 +121,73 @@ def broker_readiness() -> dict:
     }
 
 
+def projection_receipt(bound: dict | None = None) -> dict:
+    bound = bound or contract()
+    base = {
+        "interface": PROJECTION_INTERFACE,
+        "version": 1,
+        "workplan_id": "RAILIANCE-WP-0025",
+        "state": "projected",
+        "lease_id": "custody:" + "f" * 32,
+        "engagement_id": bound["engagement_id"],
+        "target": {
+            "id": bound["target"]["id"],
+            "revision": bound["target"]["revision"],
+            "image_digest": bound["target"]["image_digest"],
+        },
+        "projection_contract_digest": contract_digest(bound),
+        "broker_receipt_digest": digest(broker_readiness(bound)),
+        "projected_at": "2026-08-22T12:02:00Z",
+        "expires_at": bound["window"]["expires_at"],
+        "identities": sorted(
+            (
+                {
+                    "handle": item["handle"],
+                    "role": item["role"],
+                    "sender_name": item["sender_name"],
+                    "mount_path": item["mount_path"],
+                }
+                for item in bound["identities"]
+            ),
+            key=lambda item: item["handle"],
+        ),
+        "resources": {
+            "names": resource_names(bound),
+            "uids": {
+                "store": "uid-store",
+                "external_secret": "uid-es",
+                "mounted_secret": "uid-secret",
+            },
+        },
+        "cleanup_authority": "railiance-platform",
+        "secret_values_observed": False,
+    }
+    return {**base, "receipt_id": "sha256:" + digest(base)}
+
+
+def cleanup_receipt(bound: dict | None = None, projection: dict | None = None) -> dict:
+    bound = bound or contract()
+    projection = projection or projection_receipt(bound)
+    return {
+        "interface": CLEANUP_INTERFACE,
+        "version": 1,
+        "workplan_id": "RAILIANCE-WP-0025",
+        "state": "cleaned",
+        "lease_id": projection["lease_id"],
+        "engagement_id": bound["engagement_id"],
+        "projection_receipt_id": projection["receipt_id"],
+        "cleaned_at": "2026-08-22T12:14:00Z",
+        "removed_resources": [resource_names(bound)["store"]],
+        "target_ready": True,
+        "secret_values_observed": False,
+    }
+
+
 def live_record():
     return {
         "engagement_id": "WH-ENG-FIXTURE-1", "authorization_id": "auth-1",
         "authorizer": "operator", "approved_at": "2026-08-22T11:00:00Z",
-        "expires_at": "2099-01-01T00:00:00Z", "target": "https://fixture.invalid",
+        "expires_at": "2026-08-22T12:15:00Z", "target": "https://fixture.invalid",
         "target_id": "audit-core", "target_owner": "audit-core",
         "environment": "build", "source": "runner", "approval_class": "live-e2",
         "plane_namespace": "whitehat", "runner_image_digest": "sha256:abc",
@@ -176,8 +195,8 @@ def live_record():
         "credential_lane": "receipt", "credential_role": "runtime",
         "credential_max_ttl_seconds": 900, "techniques": ["e2-differential"],
         "prohibited_techniques": ["saturation"], "rate_limit_per_minute": 10,
-        "max_concurrency": 1, "window_start": "2026-08-22T11:00:00Z",
-        "window_end": "2099-01-01T00:00:00Z", "operator_contact": "operator",
+        "max_concurrency": 1, "window_start": "2026-08-22T12:00:00Z",
+        "window_end": "2026-08-22T12:15:00Z", "operator_contact": "operator",
         "abort_contact": "operator", "posture_claim": "E2",
         "attacker_model": "E2-authenticated-tenant-a",
         "finding_destination": "risk-nexus",
@@ -200,26 +219,129 @@ def test_four_custody_schemas_are_published():
 
 
 def test_adapter_validates_all_four_document_kinds():
-    assert validate_projection_contract(contract())["engagement_id"] == "WH-ENG-FIXTURE-1"
-    assert validate_projection_receipt(projection_receipt(), contract=contract())["state"] == "projected"
-    assert validate_cleanup_receipt(cleanup_receipt(), projection=projection_receipt())["state"] == "cleaned"
-    assert validate_broker_readiness(broker_readiness())["owner"] == "whitehat-security"
+    bound = contract()
+    projection = projection_receipt(bound)
+    assert validate_projection_contract(bound)["engagement_id"] == "WH-ENG-FIXTURE-1"
+    assert validate_projection_receipt(projection, contract=bound)["state"] == "projected"
+    assert validate_cleanup_receipt(
+        cleanup_receipt(bound, projection), projection=projection, contract=bound
+    )["state"] == "cleaned"
+    assert validate_broker_readiness(
+        broker_readiness(bound), contract=bound, now=NOW
+    )["owner"] == "whitehat-security"
 
 
 def test_adapter_rejects_secret_material():
     tainted = projection_receipt()
     tainted["token"] = "never"
     with pytest.raises(AuthorizationError, match="secret material"):
-        validate_projection_receipt(tainted)
+        validate_projection_receipt(tainted, contract=contract())
+
+
+def test_receipt_without_contract_is_refused(tmp_path):
+    path = tmp_path / "receipt.json"
+    path.write_text(json.dumps(projection_receipt()), encoding="utf-8")
+    with pytest.raises(AuthorizationError, match="requires a bound contract"):
+        broker_from_receipt(path)
+
+
+def test_noncanonical_receipt_id_is_refused():
+    receipt = projection_receipt()
+    receipt["receipt_id"] = "sha256:" + "e" * 64
+    with pytest.raises(AuthorizationError, match="canonical content digest"):
+        validate_projection_receipt(receipt, contract=contract())
+
+
+def test_stale_contract_digest_is_refused():
+    receipt = projection_receipt()
+    receipt["projection_contract_digest"] = "1" * 64
+    receipt["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in receipt.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="contract digest"):
+        validate_projection_receipt(receipt, contract=contract())
+
+
+def test_incomplete_resource_uids_are_refused():
+    bound = contract()
+    receipt = projection_receipt(bound)
+    receipt["resources"]["uids"].pop("store")
+    receipt["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in receipt.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="exact Kubernetes UIDs"):
+        validate_projection_receipt(receipt, contract=bound)
+
+
+def test_target_identity_resource_time_and_broker_digest_are_bound():
+    bound = contract()
+    receipt = projection_receipt(bound)
+    mismatched = copy.deepcopy(receipt)
+    mismatched["target"]["id"] = "other"
+    mismatched["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in mismatched.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="target"):
+        validate_projection_receipt(mismatched, contract=bound)
+
+    mismatched = copy.deepcopy(receipt)
+    mismatched["identities"][0]["sender_name"] = "wrong"
+    mismatched["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in mismatched.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="identities"):
+        validate_projection_receipt(mismatched, contract=bound)
+
+    mismatched = copy.deepcopy(receipt)
+    mismatched["resources"]["names"]["store"] = "custody-wrong"
+    mismatched["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in mismatched.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="resources"):
+        validate_projection_receipt(mismatched, contract=bound)
+
+    mismatched = copy.deepcopy(receipt)
+    mismatched["expires_at"] = "2026-08-22T12:14:00Z"
+    mismatched["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in mismatched.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="projection/expiry"):
+        validate_projection_receipt(mismatched, contract=bound)
+
+    mismatched = copy.deepcopy(receipt)
+    mismatched["broker_receipt_digest"] = "0" * 64
+    mismatched["receipt_id"] = "sha256:" + digest(
+        {key: value for key, value in mismatched.items() if key != "receipt_id"}
+    )
+    with pytest.raises(AuthorizationError, match="broker digest"):
+        PlatformCustodyBroker(
+            mismatched, contract=bound, broker=broker_readiness(bound), now=NOW
+        )
+
+
+def test_platform_validator_accepts_the_canonical_fixture():
+    scripts = Path.home() / "railiance-platform" / "scripts"
+    if str(scripts) not in sys.path:
+        sys.path.insert(0, str(scripts))
+    import custody_contract
+
+    bound = contract()
+    receipt = projection_receipt(bound)
+    broker = broker_readiness(bound)
+    assert receipt is custody_contract.validate_projection_receipt(receipt, bound)
+    assert broker is custody_contract.validate_broker_receipt(broker, bound, now=NOW)
 
 
 def test_platform_broker_issues_handles_and_supports_cleanup(tmp_path):
     path = tmp_path / "engagement.json"
     path.write_text(json.dumps(live_record()), encoding="utf-8")
     engagement = Engagement.load(path, now=NOW)
-    broker = PlatformCustodyBroker(projection_receipt(), contract=contract())
+    bound = contract()
+    receipt = projection_receipt(bound)
+    broker = PlatformCustodyBroker(
+        receipt, contract=bound, broker=broker_readiness(bound), now=NOW
+    )
     assert broker.cleanup_request_supported is True
-    from whitehat_security.targets import load_registration
     lease = admit(
         engagement=engagement,
         registration=load_registration("targets/audit-core-e2.json"),
@@ -233,13 +355,19 @@ def test_platform_broker_issues_handles_and_supports_cleanup(tmp_path):
     with pytest.raises(AuthorizationError, match="custody must revoke"):
         broker.revoke(lease.lease_id)
     cleaned = PlatformCustodyBroker(
-        projection_receipt(), contract=contract(), cleanup=cleanup_receipt()
+        receipt,
+        contract=bound,
+        cleanup=cleanup_receipt(bound, receipt),
+        broker=broker_readiness(bound),
+        now=NOW,
     )
     cleaned.revoke(lease.lease_id)
 
 
 def test_cleanup_receipt_must_match_lease():
+    bound = contract()
+    projection = projection_receipt(bound)
     with pytest.raises(AuthorizationError, match="lease_id"):
-        bad = cleanup_receipt()
+        bad = cleanup_receipt(bound, projection)
         bad["lease_id"] = "custody:" + "0" * 32
-        validate_cleanup_receipt(bad, projection=projection_receipt())
+        validate_cleanup_receipt(bad, projection=projection, contract=bound)
diff --git a/workplans/WHITEHAT-WP-0004-canonical-custody-binding.md b/workplans/WHITEHAT-WP-0004-canonical-custody-binding.md
new file mode 100644
index 0000000..dd642dd
--- /dev/null
+++ b/workplans/WHITEHAT-WP-0004-canonical-custody-binding.md
@@ -0,0 +1,51 @@
+---
+id: WHITEHAT-WP-0004
+type: workplan
+title: "Bind the WP-0025 adapter to canonical, fail-closed custody receipts"
+domain: infotech
+repo: whitehat-security
+status: finished
+owner: net-kingdom
+topic_slug: whitehat-security
+created: "2026-08-22"
+updated: "2026-08-22"
+related:
+  - WHITEHAT-WP-0003
+  - RAILIANCE-WP-0025
+---
+
+# WHITEHAT-WP-0004 — canonical custody binding
+
+## Goal
+
+Close the Railiance WP-0025 owner review of adapter `1a38080` / HEAD
+`da6f5fb`: the consumer discovered the four schemas and its focused tests
+passed, but it was not fail-closed or canonically bound. A live projection
+receipt must not admit a plane lease unless it matches a supplied projection
+contract.
+
+This plan authorizes no engagement, runner, credential, or traffic.
+
+## Origin
+
+Platform progress `d1fce546` (2026-08-22T20:09:59Z) on RAILIANCE-WP-0025 T03:
+noncanonical `receipt_id`, `projection_contract_digest` not derived from the
+supplied contract, incomplete resource UIDs accepted, runtime `--contract`
+optional, and receipt validation unbound from target, identities, resources,
+broker digest, times, and canonical receipt id.
+
+## Tasks
+
+### T01 — Require a contract and bind the receipt canonically
+
+```task
+id: WHITEHAT-WP-0004-T01
+status: done
+priority: high
+```
+
+`PlatformCustodyBroker` and `admit-plane` refuse a WP-0025 projection receipt
+without `--contract`. Validation derives the contract digest, requires the
+canonical `receipt_id`, and binds target, identities, resource names, the
+three Kubernetes UIDs, broker digest, and projection/expiry times. The focused
+adapter tests reject each of those fail-open cases.