diff --git a/azazel_processor/src/azazel_processor/__init__.py b/azazel_processor/src/azazel_processor/__init__.py
index 353d637a..e087f21c 100644
--- a/azazel_processor/src/azazel_processor/__init__.py
+++ b/azazel_processor/src/azazel_processor/__init__.py
@@ -6,9 +6,9 @@ uv'd'mim, Yoma 62a). One goat to HaShem (processing); one goat to
 Azazel (disposal). The two channels are provisioned at parity, from
 the same pool, with assignment blind to the operator.
 
-Build state: commit 5 — orchestrator state machine added. See
-BUILD_AZAZEL.md for the full 10-commit staging plan and the
-12-property → code mapping from azazel_engineering_reading.md §14.
+Build state: commit 6 — protocol envelope added. The Python side of
+the build is now feature-complete; commits 7-9 wire the cross-language
+integrations (L3, observability endpoint, intake-side routing).
 
 Properties defended so far:
   - Property 2  (blind routing / goral)         — cast_lot
@@ -17,6 +17,8 @@ Properties defended so far:
   - Property 5  (provisioned infrastructure)    — checkpoint persistence
   - Property 7  (authorized routing)            — AzazelRecord owns
                                                   the routing decision
+  - Property 8  (protocol-restricted access)    — envelope gate at
+                                                  dispatch entry
   - Property 10 (hard termination)              — DESTROYED checkpoint
                                                   + record without payload
   - Property 11 (classification discipline)     — AzazelStage*
@@ -34,9 +36,13 @@ Public surface:
     GoralError                                  — blind routing
   AzazelInput, AzazelRecord                     — orchestrator data types
   dispatch_for_disposal, list_in_flight         — orchestrator API
+  ProtocolViolation, authorize_disposal,
+    is_yom_kippur_protocol_active,
+    has_explicit_disposal_authorization,
+    set_yom_kippur_window,
+    clear_yom_kippur_window                     — protocol envelope
 
 Pending in subsequent commits:
-  protocol envelope (commit 6 — protocol-restricted access)
   L3 azazel_records integration (commit 7)
   /peah/azazel_log endpoint (commit 8)
   Korban→Azazel routing + chatzotzrot (commit 9)
@@ -56,6 +62,15 @@ from azazel_processor.goral import (
     cast_lot,
     cast_lot_outcome_id,
 )
+from azazel_processor.protocol import (
+    ProtocolViolation,
+    assert_protocol_envelope_active,
+    authorize_disposal,
+    clear_yom_kippur_window,
+    has_explicit_disposal_authorization,
+    is_yom_kippur_protocol_active,
+    set_yom_kippur_window,
+)
 from azazel_processor.shaliach import (
     IshItti,
     ShaliachError,
@@ -97,4 +112,11 @@ __all__ = [
     "dispatch_for_disposal",
     "list_in_flight",
     "DEFAULT_IN_FLIGHT_DIR",
+    "ProtocolViolation",
+    "authorize_disposal",
+    "is_yom_kippur_protocol_active",
+    "has_explicit_disposal_authorization",
+    "set_yom_kippur_window",
+    "clear_yom_kippur_window",
+    "assert_protocol_envelope_active",
 ]
diff --git a/azazel_processor/src/azazel_processor/azazel.py b/azazel_processor/src/azazel_processor/azazel.py
index 3b4c4f35..4bdc251d 100644
--- a/azazel_processor/src/azazel_processor/azazel.py
+++ b/azazel_processor/src/azazel_processor/azazel.py
@@ -69,6 +69,7 @@ from typing import Any, Callable, Optional
 
 from azazel_processor.azazel_record import AzazelRecord
 from azazel_processor.eretz_gezerah import ERETZ_GEZERAH
+from azazel_processor.protocol import assert_protocol_envelope_active
 from azazel_processor.shaliach import IshItti, assert_shaliach_active
 from azazel_processor.stages import AzazelStage, AzazelStaged
 from azazel_processor.vidui import Vidui
@@ -203,6 +204,13 @@ def dispatch_for_disposal(
         ValueError:    case_ref is not filename-safe, or other input
                        validation fails
     """
+    # Protocol envelope gate — property 8
+    # Must be the FIRST check: invoking the Azazel channel outside the
+    # envelope is the avodah-zarah shape (Vayikra 17:7), refused before
+    # any other side-effect (no shaliach activation, no payload
+    # registration, no checkpoint persistence).
+    assert_protocol_envelope_active()
+
     # Role gate — property 4
     assert_shaliach_active(handler)
 
diff --git a/azazel_processor/src/azazel_processor/protocol.py b/azazel_processor/src/azazel_processor/protocol.py
new file mode 100644
index 00000000..218aa8f8
--- /dev/null
+++ b/azazel_processor/src/azazel_processor/protocol.py
@@ -0,0 +1,202 @@
+"""
+Protocol envelope — property 8 (protocol-restricted access).
+
+Vayikra 16 specifies the Azazel goat goes ONCE A YEAR, on Yom Kippur,
+under the full ritual envelope: the kohen gadol presides, the lots
+are cast, the vidui is enumerated, the goat is sent by the ish itti.
+
+Vayikra 17:7 prohibits the same routing OUTSIDE that envelope:
+וְלֹא־יִזְבְּחוּ עוֹד אֶת־זִבְחֵיהֶם לַשְּׂעִירִם — "they shall no
+longer offer their sacrifices to the sa'irim." Same destination,
+different routing authority. Inside the envelope it is the legitimate
+Azazel-path; outside, it is avodah zarah — the failure mode
+specs/eish_zarah_reading.md catalogs.
+
+In Shorashim software:
+
+  - is_yom_kippur_protocol_active() — predicate: are we in the
+    annual Yom Kippur window the operator has configured? The
+    Hebrew-calendar conversion is left to the operator (set the
+    window explicitly via set_yom_kippur_window).
+
+  - authorize_disposal() — context manager: marks the current
+    thread as having explicit authorization for ONE disposal cycle.
+    Used for event-driven disposals during the year (e.g. an
+    empty-vital korban arriving outside the annual window). The
+    authorization is per-thread, scoped to the with-block; it is
+    NOT a persistent flag the operator can leave set.
+
+  - assert_protocol_envelope_active() — gate: raises ProtocolViolation
+    if NEITHER condition is met. dispatch_for_disposal calls this
+    at entry.
+
+Why authorize_disposal() is a context manager rather than a flag:
+
+A persistent flag would mean an operator could "set authorization
+true and leave it" — which is exactly the avodah zarah shape (using
+the channel without the protocol envelope). The context manager
+forces explicit scope: the authorization exists ONLY within the
+with-block, and only on the thread that opened it. A function called
+across the with-block boundary loses authorization unless the caller
+reopens it.
+
+Why per-thread:
+
+If authorization were process-wide, two concurrent disposals could
+share authorization without explicit coordination — operator A's
+authorize_disposal() would silently authorize operator B's
+dispatch_for_disposal(). Per-thread isolation forces each disposal
+to carry its own authorization explicitly.
+"""
+
+import contextlib
+import threading
+from datetime import date, datetime, timezone
+from typing import Optional
+
+
+class ProtocolViolation(RuntimeError):
+    """Raised when a disposal-channel function is invoked outside
+    the protocol envelope.
+
+    The Mishkan analog: someone offered a sacrifice to the sa'irim
+    outside Yom Kippur (Vayikra 17:7). Same destination, different
+    routing authority — and outside the envelope, the routing
+    authority is illegitimate. The system refuses.
+    """
+
+
+# ============================================================
+# Yom Kippur annual window (operator-configured)
+# ============================================================
+#
+# Module-level state because the window is process-global by design:
+# Yom Kippur is one date for the system, not per-thread. The operator
+# sets it once at process startup and it applies to every subsequent
+# dispatch on this process.
+#
+# Hebrew-calendar conversion is the operator's responsibility — we
+# do not bring a Hebrew-calendar library into azazel_processor's
+# dependency surface. The vav_pipeline (Elixir) side already knows
+# how to compute Hebrew dates; for now this module just stores the
+# Gregorian range the operator supplies.
+
+_yom_kippur_window: Optional[tuple[date, date]] = None
+_window_lock = threading.Lock()
+
+
+def set_yom_kippur_window(start: date, end: date) -> None:
+    """Configure the annual Yom Kippur window.
+
+    `start` and `end` are inclusive Gregorian dates. The operator
+    is responsible for setting the window each year (or a process
+    that wraps multiple years). Setting an empty window
+    (start > end) clears the window — disposal must then go through
+    the explicit-authorization path.
+
+    Thread-safe; the lock prevents two concurrent set_yom_kippur_window
+    calls from leaving the window in an inconsistent state.
+    """
+    global _yom_kippur_window
+    with _window_lock:
+        if start > end:
+            _yom_kippur_window = None
+        else:
+            _yom_kippur_window = (start, end)
+
+
+def clear_yom_kippur_window() -> None:
+    """Clear the configured window. After this, only explicit
+    authorization (via authorize_disposal context manager) permits
+    dispatch."""
+    global _yom_kippur_window
+    with _window_lock:
+        _yom_kippur_window = None
+
+
+def is_yom_kippur_protocol_active(today: Optional[date] = None) -> bool:
+    """True iff the operator has configured a Yom Kippur window AND
+    today falls within it.
+
+    `today` defaults to UTC today; tests can pass an explicit date.
+    """
+    with _window_lock:
+        window = _yom_kippur_window
+
+    if window is None:
+        return False
+    if today is None:
+        today = datetime.now(timezone.utc).date()
+    start, end = window
+    return start <= today <= end
+
+
+# ============================================================
+# Per-thread explicit-authorization scope
+# ============================================================
+#
+# threading.local() gives us per-thread isolation: authorize_disposal()
+# sets a flag visible only on the current thread; other threads
+# cannot see or share it.
+
+_thread_local = threading.local()
+
+
+def has_explicit_disposal_authorization() -> bool:
+    """True iff the current thread is inside an authorize_disposal()
+    with-block. Per-thread, scoped to the with-block."""
+    return getattr(_thread_local, "authorized", 0) > 0
+
+
+@contextlib.contextmanager
+def authorize_disposal():
+    """Context manager: explicitly authorize one disposal cycle on
+    the current thread.
+
+    Use for event-driven disposals during the year (outside the
+    Yom Kippur window). The authorization exists ONLY within the
+    with-block; on exit the flag is decremented and (if reaching 0)
+    cleared. Reentrant — nesting is permitted (each entry
+    increments the counter, each exit decrements).
+
+    Usage:
+
+        from azazel_processor.protocol import authorize_disposal
+        from azazel_processor.azazel import dispatch_for_disposal
+
+        with authorize_disposal():
+            record = dispatch_for_disposal(input, ...)
+    """
+    current = getattr(_thread_local, "authorized", 0)
+    _thread_local.authorized = current + 1
+    try:
+        yield
+    finally:
+        _thread_local.authorized = max(0, _thread_local.authorized - 1)
+
+
+def assert_protocol_envelope_active() -> None:
+    """Gate. Raises ProtocolViolation if NEITHER:
+      - is_yom_kippur_protocol_active() is True (operator-configured
+        annual window covers today)
+      - has_explicit_disposal_authorization() is True (current thread
+        is inside an authorize_disposal() with-block)
+
+    Called by dispatch_for_disposal() at entry. Outside this gate,
+    invoking the Azazel channel is the avodah zarah shape (Vayikra
+    17:7); the system refuses.
+    """
+    if is_yom_kippur_protocol_active():
+        return
+    if has_explicit_disposal_authorization():
+        return
+
+    raise ProtocolViolation(
+        "Azazel disposal cannot proceed outside the protocol envelope. "
+        "Either: (a) configure the Yom Kippur window via "
+        "set_yom_kippur_window(start, end) and invoke during it, or "
+        "(b) wrap the dispatch in an authorize_disposal() context "
+        "manager. Invoking the disposal channel privately is the "
+        "avodah zarah shape (Vayikra 17:7 — lo yizbechu od et "
+        "zivchehem la'sa'irim)."
+    )
diff --git a/azazel_processor/test/test_azazel.py b/azazel_processor/test/test_azazel.py
index 53dfdf16..0f59f4a4 100644
--- a/azazel_processor/test/test_azazel.py
+++ b/azazel_processor/test/test_azazel.py
@@ -30,6 +30,7 @@ from azazel_processor.azazel import (
 )
 from azazel_processor.azazel_record import AzazelRecord
 from azazel_processor.eretz_gezerah import ERETZ_GEZERAH, is_eretz_gezerah
+from azazel_processor.protocol import authorize_disposal
 from azazel_processor.shaliach import IshItti, ShaliachError
 from azazel_processor.stages import AzazelStage
 from azazel_processor.vidui import confess_empty_vital
@@ -51,6 +52,17 @@ def active_handler():
         h.tevilah()
 
 
+@pytest.fixture(autouse=True)
+def _envelope():
+    """Open the protocol envelope around every test in this module.
+    The protocol restriction (property 8) is verified separately in
+    test_protocol_restriction.py; the orchestrator tests assume the
+    envelope is open so they can exercise the rest of the state
+    machine without re-opening per dispatch."""
+    with authorize_disposal():
+        yield
+
+
 def _make_input(case_ref="case-001", payload=None):
     return AzazelInput(
         case_ref=case_ref,
diff --git a/azazel_processor/test/test_protocol_restriction.py b/azazel_processor/test/test_protocol_restriction.py
new file mode 100644
index 00000000..59540df4
--- /dev/null
+++ b/azazel_processor/test/test_protocol_restriction.py
@@ -0,0 +1,262 @@
+"""
+Tests for the protocol envelope (property 8) — protocol-restricted
+access. Vayikra 17:7: lo yizbechu od et zivchehem la'sa'irim — the
+same destination outside the Yom Kippur envelope is avodah zarah.
+
+These tests deliberately do NOT auto-open the envelope (unlike
+test_azazel.py). They exercise the gate directly: verify dispatch
+refuses outside the envelope, accepts inside the Yom Kippur window,
+accepts inside an authorize_disposal context, and that the
+authorization scope is per-thread and properly nested.
+"""
+
+import pathlib
+import tempfile
+import threading
+from datetime import date, timedelta
+
+import pytest
+
+from azazel_processor.azazel import AzazelInput, dispatch_for_disposal
+from azazel_processor.protocol import (
+    ProtocolViolation,
+    assert_protocol_envelope_active,
+    authorize_disposal,
+    clear_yom_kippur_window,
+    has_explicit_disposal_authorization,
+    is_yom_kippur_protocol_active,
+    set_yom_kippur_window,
+)
+from azazel_processor.shaliach import IshItti
+from azazel_processor.vidui import confess_empty_vital
+
+
+@pytest.fixture(autouse=True)
+def _isolate_protocol_state():
+    """Ensure each test starts with no Yom Kippur window and no
+    leftover thread-local authorization. Module-level state in
+    protocol.py persists across tests if we don't reset."""
+    clear_yom_kippur_window()
+    yield
+    clear_yom_kippur_window()
+
+
+@pytest.fixture
+def tmp_in_flight():
+    with tempfile.TemporaryDirectory(prefix="azazel-protocol-test-") as d:
+        yield pathlib.Path(d)
+
+
+@pytest.fixture
+def active_handler():
+    h = IshItti("aharon")
+    h.activate()
+    yield h
+    if h.is_active():
+        h.tevilah()
+
+
+def _input(case_ref="proto-001"):
+    return AzazelInput(
+        case_ref=case_ref, payload={}, classification="empty_vital"
+    )
+
+
+def _vidui():
+    return confess_empty_vital("placeholder", confessor="kohen-gadol")
+
+
+# ============================================================
+# Default state: refused
+# ============================================================
+
+
+def test_default_state_refuses_dispatch(active_handler, tmp_in_flight):
+    """No Yom Kippur window configured + no authorization → ProtocolViolation."""
+    with pytest.raises(ProtocolViolation) as exc:
+        dispatch_for_disposal(
+            _input(),
+            handler=active_handler,
+            confess_with=_vidui(),
+            authorized_by="kohen-gadol",
+            in_flight_dir=tmp_in_flight,
+        )
+    msg = str(exc.value)
+    # Error message names both legitimate paths
+    assert "yom kippur" in msg.lower() or "set_yom_kippur_window" in msg
+    assert "authorize_disposal" in msg
+
+
+def test_default_state_assert_raises():
+    with pytest.raises(ProtocolViolation):
+        assert_protocol_envelope_active()
+
+
+def test_default_state_neither_predicate_active():
+    assert is_yom_kippur_protocol_active() is False
+    assert has_explicit_disposal_authorization() is False
+
+
+# ============================================================
+# Yom Kippur window
+# ============================================================
+
+
+def test_yom_kippur_window_today_inside_active():
+    today = date(2026, 9, 21)
+    set_yom_kippur_window(today - timedelta(days=3), today + timedelta(days=3))
+    assert is_yom_kippur_protocol_active(today=today) is True
+
+
+def test_yom_kippur_window_today_outside_inactive():
+    set_yom_kippur_window(date(2026, 9, 1), date(2026, 9, 5))
+    assert is_yom_kippur_protocol_active(today=date(2026, 12, 1)) is False
+
+
+def test_yom_kippur_window_inverted_clears():
+    """Setting a window where start > end clears it (no valid window)."""
+    set_yom_kippur_window(date(2026, 9, 5), date(2026, 9, 1))
+    assert is_yom_kippur_protocol_active(today=date(2026, 9, 3)) is False
+
+
+def test_yom_kippur_window_inclusive_at_boundaries():
+    set_yom_kippur_window(date(2026, 9, 1), date(2026, 9, 5))
+    assert is_yom_kippur_protocol_active(today=date(2026, 9, 1)) is True
+    assert is_yom_kippur_protocol_active(today=date(2026, 9, 5)) is True
+    assert is_yom_kippur_protocol_active(today=date(2026, 8, 31)) is False
+    assert is_yom_kippur_protocol_active(today=date(2026, 9, 6)) is False
+
+
+def test_clear_yom_kippur_window_disables():
+    set_yom_kippur_window(date(2026, 1, 1), date(2026, 12, 31))
+    assert is_yom_kippur_protocol_active(today=date(2026, 6, 1)) is True
+    clear_yom_kippur_window()
+    assert is_yom_kippur_protocol_active(today=date(2026, 6, 1)) is False
+
+
+# ============================================================
+# Explicit-authorization context manager
+# ============================================================
+
+
+def test_authorize_disposal_inside_block_active():
+    assert has_explicit_disposal_authorization() is False
+    with authorize_disposal():
+        assert has_explicit_disposal_authorization() is True
+    assert has_explicit_disposal_authorization() is False
+
+
+def test_authorize_disposal_nested_blocks_decrement_correctly():
+    """Reentrancy: nested with-blocks each increment, each exit
+    decrements. Authorization stays active while at least one is open."""
+    assert has_explicit_disposal_authorization() is False
+    with authorize_disposal():
+        assert has_explicit_disposal_authorization() is True
+        with authorize_disposal():
+            assert has_explicit_disposal_authorization() is True
+        # Inner exited; outer still holds
+        assert has_explicit_disposal_authorization() is True
+    assert has_explicit_disposal_authorization() is False
+
+
+def test_authorize_disposal_exception_inside_still_clears():
+    """If an exception fires inside the with-block, the authorization
+    is still cleared on exit (try/finally guarantee)."""
+    with pytest.raises(RuntimeError):
+        with authorize_disposal():
+            assert has_explicit_disposal_authorization() is True
+            raise RuntimeError("boom")
+    assert has_explicit_disposal_authorization() is False
+
+
+def test_authorize_disposal_is_per_thread():
+    """One thread's authorization MUST NOT leak to another. Per-thread
+    isolation is the load-bearing scoping property."""
+    sibling_authorized = []
+
+    def sibling():
+        sibling_authorized.append(has_explicit_disposal_authorization())
+
+    with authorize_disposal():
+        t = threading.Thread(target=sibling)
+        t.start()
+        t.join()
+
+    assert sibling_authorized == [False]
+
+
+# ============================================================
+# dispatch_for_disposal honors the gate
+# ============================================================
+
+
+def test_dispatch_proceeds_inside_authorize_disposal(
+    active_handler, tmp_in_flight
+):
+    with authorize_disposal():
+        record = dispatch_for_disposal(
+            _input(),
+            handler=active_handler,
+            confess_with=_vidui(),
+            authorized_by="kohen-gadol",
+            in_flight_dir=tmp_in_flight,
+        )
+    assert record is not None
+
+
+def test_dispatch_proceeds_inside_yom_kippur_window(
+    active_handler, tmp_in_flight
+):
+    today = date.today()
+    set_yom_kippur_window(today - timedelta(days=1), today + timedelta(days=1))
+    record = dispatch_for_disposal(
+        _input(),
+        handler=active_handler,
+        confess_with=_vidui(),
+        authorized_by="kohen-gadol",
+        in_flight_dir=tmp_in_flight,
+    )
+    assert record is not None
+
+
+def test_dispatch_outside_envelope_writes_no_in_flight_file(
+    active_handler, tmp_in_flight
+):
+    """Property 8 + 5 interaction: when the gate refuses, NO
+    side-effect occurs. No checkpoint persisted, no payload held,
+    no L3 record created."""
+    try:
+        dispatch_for_disposal(
+            _input(case_ref="must-not-persist-001"),
+            handler=active_handler,
+            confess_with=_vidui(),
+            authorized_by="kohen-gadol",
+            in_flight_dir=tmp_in_flight,
+        )
+    except ProtocolViolation:
+        pass
+
+    # No file should have been created
+    assert not (tmp_in_flight / "must-not-persist-001.json").exists()
+    # The shaliach should not have held the payload
+    assert active_handler.held_payload_count() == 0
+
+
+def test_protocol_violation_raised_before_any_other_check(
+    active_handler, tmp_in_flight
+):
+    """The protocol envelope is checked FIRST — even before the role
+    gate. An inactive handler invoked outside the envelope should
+    raise ProtocolViolation, not ShaliachError. This ordering matters
+    because protocol restriction is the avodah-zarah-shape defense:
+    we refuse on protocol grounds before doing any other validation."""
+    h = IshItti("aharon")
+    # Don't activate
+    with pytest.raises(ProtocolViolation):
+        dispatch_for_disposal(
+            _input(),
+            handler=h,
+            confess_with=_vidui(),
+            authorized_by="kohen-gadol",
+            in_flight_dir=tmp_in_flight,
+        )