diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 378b6ebd..b39fb525 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -9,7 +9,7 @@ repos:
         exclude: docs/auto_examples
 - repo: https://github.com/charliermarsh/ruff-pre-commit
   # Ruff version.
-  rev: v0.8.1
+  rev: v0.15.0
   hooks:
     # Run the linter.
     - id: ruff
diff --git a/docs/guards.md b/docs/guards.md
index 65eaf9e6..84140657 100644
--- a/docs/guards.md
+++ b/docs/guards.md
@@ -47,7 +47,7 @@ To control the evaluation order, declare transitions in the desired order:
 ```python
 # Declare in the order you want them checked:
 first = state_a.to(state_b, cond="check1")   # Checked FIRST
-second = state_a.to(state_c, cond="check2")  # Checked SECOND  
+second = state_a.to(state_c, cond="check2")  # Checked SECOND
 third = state_a.to(state_d, cond="check3")   # Checked THIRD
 
 my_event = first | second | third  # Order matches declaration
@@ -159,6 +159,79 @@ So, a condition `s1.to(s2, cond=lambda: [])` will evaluate as `False`, as an emp
 **falsy** value.
 ```
 
+### Checking enabled events
+
+The {ref}`StateMachine.allowed_events` property returns events reachable from the current state,
+but it does **not** evaluate `cond`/`unless` guards. To check which events actually have their
+conditions satisfied, use {ref}`StateMachine.enabled_events`.
+
+```{testsetup}
+
+>>> from statemachine import StateMachine, State
+
+```
+
+```py
+>>> class ApprovalMachine(StateMachine):
+...     pending = State(initial=True)
+...     approved = State(final=True)
+...     rejected = State(final=True)
+...
+...     approve = pending.to(approved, cond="is_manager")
+...     reject = pending.to(rejected)
+...
+...     is_manager = False
+
+>>> sm = ApprovalMachine()
+
+>>> [e.id for e in sm.allowed_events]
+['approve', 'reject']
+
+>>> [e.id for e in sm.enabled_events()]
+['reject']
+
+>>> sm.is_manager = True
+
+>>> [e.id for e in sm.enabled_events()]
+['approve', 'reject']
+
+```
+
+`enabled_events` is a method (not a property) because conditions may depend on runtime
+arguments. Any `*args`/`**kwargs` passed to `enabled_events()` are forwarded to the
+condition callbacks, just like when triggering an event:
+
+```py
+>>> class TaskMachine(StateMachine):
+...     idle = State(initial=True)
+...     running = State(final=True)
+...
+...     start = idle.to(running, cond="has_enough_resources")
+...
+...     def has_enough_resources(self, cpu=0):
+...         return cpu >= 4
+
+>>> sm = TaskMachine()
+
+>>> sm.enabled_events()
+[]
+
+>>> [e.id for e in sm.enabled_events(cpu=8)]
+['start']
+
+```
+
+```{tip}
+This is useful for UI scenarios where you want to show or hide buttons based on whether
+an event's conditions are currently satisfied.
+```
+
+```{note}
+An event is considered **enabled** if at least one of its transitions from the current state
+has all conditions satisfied. If a condition raises an exception, the event is treated as
+enabled (permissive behavior).
+```
+
 ## Validators
 
 
diff --git a/statemachine/engines/async_.py b/statemachine/engines/async_.py
index 9d2b3f9f..ccc88496 100644
--- a/statemachine/engines/async_.py
+++ b/statemachine/engines/async_.py
@@ -97,6 +97,34 @@ async def _trigger(self, trigger_data: TriggerData):
 
         return result if executed else None
 
+    async def enabled_events(self, *args, **kwargs):
+        sm = self.sm
+        enabled = {}
+        for transition in sm.current_state.transitions:
+            for event in transition.events:
+                if event in enabled:
+                    continue
+                extended_kwargs = kwargs.copy()
+                extended_kwargs.update(
+                    {
+                        "machine": sm,
+                        "model": sm.model,
+                        "event": getattr(sm, event),
+                        "source": transition.source,
+                        "target": transition.target,
+                        "state": sm.current_state,
+                        "transition": transition,
+                    }
+                )
+                try:
+                    if await sm._callbacks.async_all(
+                        transition.cond.key, *args, **extended_kwargs
+                    ):
+                        enabled[event] = getattr(sm, event)
+                except Exception:
+                    enabled[event] = getattr(sm, event)
+        return list(enabled.values())
+
     async def _activate(self, trigger_data: TriggerData, transition: "Transition"):
         event_data = EventData(trigger_data=trigger_data, transition=transition)
         args, kwargs = event_data.args, event_data.extended_kwargs
diff --git a/statemachine/engines/sync.py b/statemachine/engines/sync.py
index 4400cd08..d65ef119 100644
--- a/statemachine/engines/sync.py
+++ b/statemachine/engines/sync.py
@@ -99,6 +99,32 @@ def _trigger(self, trigger_data: TriggerData):
 
         return result if executed else None
 
+    def enabled_events(self, *args, **kwargs):
+        sm = self.sm
+        enabled = {}
+        for transition in sm.current_state.transitions:
+            for event in transition.events:
+                if event in enabled:
+                    continue
+                extended_kwargs = kwargs.copy()
+                extended_kwargs.update(
+                    {
+                        "machine": sm,
+                        "model": sm.model,
+                        "event": getattr(sm, event),
+                        "source": transition.source,
+                        "target": transition.target,
+                        "state": sm.current_state,
+                        "transition": transition,
+                    }
+                )
+                try:
+                    if sm._callbacks.all(transition.cond.key, *args, **extended_kwargs):
+                        enabled[event] = getattr(sm, event)
+                except Exception:
+                    enabled[event] = getattr(sm, event)
+        return list(enabled.values())
+
     def _activate(self, trigger_data: TriggerData, transition: "Transition"):
         event_data = EventData(trigger_data=trigger_data, transition=transition)
         args, kwargs = event_data.args, event_data.extended_kwargs
diff --git a/statemachine/spec_parser.py b/statemachine/spec_parser.py
index 7596c083..1899d0a4 100644
--- a/statemachine/spec_parser.py
+++ b/statemachine/spec_parser.py
@@ -2,6 +2,7 @@
 import operator
 import re
 from functools import reduce
+from inspect import isawaitable
 from typing import Callable
 
 replacements = {"!": "not ", "^": " and ", "v": " or "}
@@ -33,8 +34,15 @@ def match_func(match):
 
 
 def custom_not(predicate: Callable) -> Callable:
-    def decorated(*args, **kwargs) -> bool:
-        return not predicate(*args, **kwargs)
+    def decorated(*args, **kwargs):
+        result = predicate(*args, **kwargs)
+        if isawaitable(result):
+
+            async def _negate():
+                return not await result
+
+            return _negate()
+        return not result
 
     decorated.__name__ = f"not({predicate.__name__})"
     unique_key = getattr(predicate, "unique_key", "")
@@ -43,8 +51,26 @@ def decorated(*args, **kwargs) -> bool:
 
 
 def custom_and(left: Callable, right: Callable) -> Callable:
-    def decorated(*args, **kwargs) -> bool:
-        return left(*args, **kwargs) and right(*args, **kwargs)  # type: ignore[no-any-return]
+    def decorated(*args, **kwargs):
+        left_result = left(*args, **kwargs)
+        if isawaitable(left_result):
+
+            async def _async_and():
+                lr = await left_result
+                if not lr:
+                    return lr
+                rr = right(*args, **kwargs)
+                if isawaitable(rr):
+                    return await rr
+                return rr
+
+            return _async_and()
+        if not left_result:
+            return left_result
+        right_result = right(*args, **kwargs)
+        if isawaitable(right_result):
+            return right_result
+        return right_result
 
     decorated.__name__ = f"({left.__name__} and {right.__name__})"
     decorated.unique_key = _unique_key(left, right, "and")  # type: ignore[attr-defined]
@@ -52,8 +78,26 @@ def decorated(*args, **kwargs) -> bool:
 
 
 def custom_or(left: Callable, right: Callable) -> Callable:
-    def decorated(*args, **kwargs) -> bool:
-        return left(*args, **kwargs) or right(*args, **kwargs)  # type: ignore[no-any-return]
+    def decorated(*args, **kwargs):
+        left_result = left(*args, **kwargs)
+        if isawaitable(left_result):
+
+            async def _async_or():
+                lr = await left_result
+                if lr:
+                    return lr
+                rr = right(*args, **kwargs)
+                if isawaitable(rr):
+                    return await rr
+                return rr
+
+            return _async_or()
+        if left_result:
+            return left_result
+        right_result = right(*args, **kwargs)
+        if isawaitable(right_result):
+            return right_result
+        return right_result
 
     decorated.__name__ = f"({left.__name__} or {right.__name__})"
     decorated.unique_key = _unique_key(left, right, "or")  # type: ignore[attr-defined]
@@ -73,8 +117,18 @@ def build_custom_operator(operator) -> Callable:
     operator_repr = comparison_repr[operator]
 
     def custom_comparator(left: Callable, right: Callable) -> Callable:
-        def decorated(*args, **kwargs) -> bool:
-            return bool(operator(left(*args, **kwargs), right(*args, **kwargs)))
+        def decorated(*args, **kwargs):
+            left_result = left(*args, **kwargs)
+            right_result = right(*args, **kwargs)
+            if isawaitable(left_result) or isawaitable(right_result):
+
+                async def _async_compare():
+                    lr = (await left_result) if isawaitable(left_result) else left_result
+                    rr = (await right_result) if isawaitable(right_result) else right_result
+                    return bool(operator(lr, rr))
+
+                return _async_compare()
+            return bool(operator(left_result, right_result))
 
         decorated.__name__ = f"({left.__name__} {operator_repr} {right.__name__})"
         decorated.unique_key = _unique_key(left, right, operator_repr)  # type: ignore[attr-defined]
diff --git a/statemachine/statemachine.py b/statemachine/statemachine.py
index ac402159..3e14edaf 100644
--- a/statemachine/statemachine.py
+++ b/statemachine/statemachine.py
@@ -147,6 +147,7 @@ def __setstate__(self, state):
         self._register_callbacks([])
         self.add_listener(*listeners.keys())
         self._engine = self._get_engine(rtc)
+        self._engine.start()
 
     def _get_initial_state(self):
         initial_state_value = self.start_value if self.start_value else self.initial_state.value
@@ -294,6 +295,24 @@ def allowed_events(self) -> "List[Event]":
         """List of the current allowed events."""
         return [getattr(self, event) for event in self.current_state.transitions.unique_events]
 
+    def enabled_events(self, *args, **kwargs):
+        """List of the current enabled events, considering guard conditions.
+
+        An event is **enabled** if at least one of its transitions from the current
+        state has all ``cond``/``unless`` guards satisfied.
+
+        Args:
+            *args: Positional arguments forwarded to condition callbacks.
+            **kwargs: Keyword arguments forwarded to condition callbacks.
+
+        Returns:
+            A list of enabled :ref:`Event` instances.
+        """
+        result = self._engine.enabled_events(*args, **kwargs)
+        if not isawaitable(result):
+            return result
+        return run_async_from_sync(result)
+
     def _put_nonblocking(self, trigger_data: TriggerData):
         """Put the trigger on the queue without blocking the caller."""
         self._engine.put(trigger_data)
diff --git a/tests/examples/user_machine.py b/tests/examples/user_machine.py
index a9fcb193..ad0320a8 100644
--- a/tests/examples/user_machine.py
+++ b/tests/examples/user_machine.py
@@ -88,7 +88,7 @@ class UserStatusMachine(StateMachine):
     def on_signup(self, token: str):
         if token == "":
             raise ValueError("Token is required")
-        self.model.verified = True
+        self.model.verified = True  # type: ignore[union-attr]
 
 
 class UserExperienceMachine(StateMachine):
diff --git a/tests/test_async.py b/tests/test_async.py
index 36af9126..7a995e88 100644
--- a/tests/test_async.py
+++ b/tests/test_async.py
@@ -96,6 +96,86 @@ def test_async_state_from_sync_context(async_order_control_machine):
     assert sm.completed.is_active
 
 
+class AsyncConditionExpressionMachine(StateMachine):
+    """Regression test for issue #535: async conditions in boolean expressions."""
+
+    s1 = State(initial=True)
+
+    go_not = s1.to.itself(cond="not cond_false")
+    go_and = s1.to.itself(cond="cond_true and cond_true")
+    go_or_false_first = s1.to.itself(cond="cond_false or cond_true")
+    go_or_true_first = s1.to.itself(cond="cond_true or cond_false")
+    go_blocked = s1.to.itself(cond="not cond_true")
+    go_and_blocked = s1.to.itself(cond="cond_true and cond_false")
+    go_or_both_false = s1.to.itself(cond="cond_false or cond_false")
+
+    async def cond_true(self):
+        return True
+
+    async def cond_false(self):
+        return False
+
+    async def on_enter_state(self, target):
+        """Async callback to ensure the SM uses AsyncEngine."""
+
+
+async def test_async_condition_not(recwarn):
+    """Issue #535: 'not cond_false' should allow the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    await sm.go_not()
+    assert sm.s1.is_active
+    assert not any("coroutine" in str(w.message) for w in recwarn.list)
+
+
+async def test_async_condition_not_blocked():
+    """Issue #535: 'not cond_true' should block the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    with pytest.raises(sm.TransitionNotAllowed):
+        await sm.go_blocked()
+
+
+async def test_async_condition_and():
+    """Issue #535: 'cond_true and cond_true' should allow the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    await sm.go_and()
+    assert sm.s1.is_active
+
+
+async def test_async_condition_and_blocked():
+    """Issue #535: 'cond_true and cond_false' should block the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    with pytest.raises(sm.TransitionNotAllowed):
+        await sm.go_and_blocked()
+
+
+async def test_async_condition_or_false_first():
+    """Issue #535: 'cond_false or cond_true' should allow the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    await sm.go_or_false_first()
+    assert sm.s1.is_active
+
+
+async def test_async_condition_or_true_first():
+    """'cond_true or cond_false' should allow the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    await sm.go_or_true_first()
+    assert sm.s1.is_active
+
+
+async def test_async_condition_or_both_false():
+    """'cond_false or cond_false' should block the transition."""
+    sm = AsyncConditionExpressionMachine()
+    await sm.activate_initial_state()
+    with pytest.raises(sm.TransitionNotAllowed):
+        await sm.go_or_both_false()
+
+
 async def test_async_state_should_be_initialized(async_order_control_machine):
     """Test that the state machine is initialized before any event is triggered
 
@@ -119,3 +199,81 @@ async def test_async_state_should_be_initialized(async_order_control_machine):
 
     await sm.activate_initial_state()
     assert sm.current_state == sm.waiting_for_payment
+
+
+class TestAsyncEnabledEvents:
+    async def test_passing_async_condition(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="is_ready")
+
+            async def is_ready(self):
+                return True
+
+        sm = MyMachine()
+        await sm.activate_initial_state()
+        assert [e.id for e in await sm.enabled_events()] == ["go"]
+
+    async def test_failing_async_condition(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="is_ready")
+
+            async def is_ready(self):
+                return False
+
+        sm = MyMachine()
+        await sm.activate_initial_state()
+        assert await sm.enabled_events() == []
+
+    async def test_kwargs_forwarded_to_async_conditions(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="check_value")
+
+            async def check_value(self, value=0):
+                return value > 10
+
+        sm = MyMachine()
+        await sm.activate_initial_state()
+        assert await sm.enabled_events() == []
+        assert [e.id for e in await sm.enabled_events(value=20)] == ["go"]
+
+    async def test_async_condition_exception_treated_as_enabled(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="bad_cond")
+
+            async def bad_cond(self):
+                raise RuntimeError("boom")
+
+        sm = MyMachine()
+        await sm.activate_initial_state()
+        assert [e.id for e in await sm.enabled_events()] == ["go"]
+
+    async def test_mixed_enabled_and_disabled_async(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State()
+            s2 = State(final=True)
+
+            go = s0.to(s1, cond="cond_true")
+            stop = s0.to(s2, cond="cond_false")
+
+            async def cond_true(self):
+                return True
+
+            async def cond_false(self):
+                return False
+
+        sm = MyMachine()
+        await sm.activate_initial_state()
+        assert [e.id for e in await sm.enabled_events()] == ["go"]
diff --git a/tests/test_copy.py b/tests/test_copy.py
index 15e2c358..b2af2819 100644
--- a/tests/test_copy.py
+++ b/tests/test_copy.py
@@ -1,3 +1,4 @@
+import asyncio
 import logging
 import pickle
 from copy import deepcopy
@@ -181,3 +182,51 @@ def test_copy_with_custom_init_and_vars(copy_method):
     assert sm2.custom == 1
     assert sm2.value == [1, 2, 3]
     assert sm2.current_state == MyStateMachine.started
+
+
+class AsyncTrafficLightMachine(StateMachine):
+    green = State(initial=True)
+    yellow = State()
+    red = State()
+
+    cycle = green.to(yellow) | yellow.to(red) | red.to(green)
+
+    async def on_enter_state(self, target):
+        """Async callback to ensure the SM uses AsyncEngine."""
+
+
+def test_copy_async_statemachine_before_activation(copy_method):
+    """Regression test for issue #544: async SM fails after pickle/deepcopy.
+
+    When an async SM is copied before activation, the copy must still be
+    activatable because ``__setstate__`` re-enqueues the ``__initial__`` event.
+    """
+    sm = AsyncTrafficLightMachine()
+    sm_copy = copy_method(sm)
+
+    async def verify():
+        await sm_copy.activate_initial_state()
+        assert sm_copy.current_state == AsyncTrafficLightMachine.green
+        await sm_copy.cycle()
+        assert sm_copy.current_state == AsyncTrafficLightMachine.yellow
+
+    asyncio.run(verify())
+
+
+def test_copy_async_statemachine_after_activation(copy_method):
+    """Copying an async SM that is already activated preserves its current state."""
+
+    async def setup_and_verify():
+        sm = AsyncTrafficLightMachine()
+        await sm.activate_initial_state()
+        await sm.cycle()
+        assert sm.current_state == AsyncTrafficLightMachine.yellow
+
+        sm_copy = copy_method(sm)
+
+        await sm_copy.activate_initial_state()
+        assert sm_copy.current_state == AsyncTrafficLightMachine.yellow
+        await sm_copy.cycle()
+        assert sm_copy.current_state == AsyncTrafficLightMachine.red
+
+    asyncio.run(setup_and_verify())
diff --git a/tests/test_signature.py b/tests/test_signature.py
index 1cb68673..ccf30232 100644
--- a/tests/test_signature.py
+++ b/tests/test_signature.py
@@ -2,7 +2,6 @@
 from functools import partial
 
 import pytest
-
 from statemachine.dispatcher import callable_method
 from statemachine.signature import SignatureAdapter
 
diff --git a/tests/test_spec_parser.py b/tests/test_spec_parser.py
index ace3a4b1..569090d9 100644
--- a/tests/test_spec_parser.py
+++ b/tests/test_spec_parser.py
@@ -1,3 +1,4 @@
+import asyncio
 import logging
 
 import pytest
@@ -247,6 +248,101 @@ def variable_hook(var_name):
         ("height > 1 and height < 2", True, ["height"]),
     ],
 )
+def async_variable_hook(var_name):
+    """Variable hook that returns async callables, for testing issue #535."""
+    values = {
+        "cond_true": True,
+        "cond_false": False,
+        "val_10": 10,
+        "val_20": 20,
+    }
+
+    value = values.get(var_name, False)
+
+    async def decorated(*args, **kwargs):
+        await asyncio.sleep(0)
+        return value
+
+    decorated.__name__ = var_name
+    return decorated
+
+
+@pytest.mark.parametrize(
+    ("expression", "expected"),
+    [
+        ("not cond_false", True),
+        ("not cond_true", False),
+        ("cond_true and cond_true", True),
+        ("cond_true and cond_false", False),
+        ("cond_false and cond_true", False),
+        ("cond_false or cond_true", True),
+        ("cond_true or cond_false", True),
+        ("cond_false or cond_false", False),
+        ("not cond_false and cond_true", True),
+        ("not (cond_true and cond_false)", True),
+        ("not (cond_false or cond_false)", True),
+        ("cond_true and not cond_false", True),
+        ("val_10 == 10", True),
+        ("val_10 != 20", True),
+        ("val_10 < val_20", True),
+        ("val_20 > val_10", True),
+        ("val_10 >= 10", True),
+        ("val_10 <= val_20", True),
+    ],
+)
+def test_async_expressions(expression, expected):
+    """Issue #535: condition expressions with async predicates must await results."""
+    parsed_expr = parse_boolean_expr(expression, async_variable_hook, operator_mapping)
+    result = parsed_expr()
+    assert asyncio.iscoroutine(result), f"Expected coroutine for async expression: {expression}"
+    assert asyncio.run(result) is expected, expression
+
+
+def mixed_variable_hook(var_name):
+    """Variable hook where some vars are sync and some are async."""
+    sync_values = {"sync_true": True, "sync_false": False, "sync_10": 10}
+    async_values = {"async_true": True, "async_false": False, "async_20": 20}
+
+    if var_name in async_values:
+        value = async_values[var_name]
+
+        async def async_decorated(*args, **kwargs):
+            await asyncio.sleep(0)
+            return value
+
+        async_decorated.__name__ = var_name
+        return async_decorated
+
+    def sync_decorated(*args, **kwargs):
+        return sync_values.get(var_name, False)
+
+    sync_decorated.__name__ = var_name
+    return sync_decorated
+
+
+@pytest.mark.parametrize(
+    ("expression", "expected"),
+    [
+        # async left, sync right
+        ("async_true and sync_true", True),
+        ("async_false or sync_true", True),
+        # sync left, async right
+        ("sync_true and async_true", True),
+        ("sync_false or async_true", True),
+        ("sync_true and async_false", False),
+        ("sync_false or async_false", False),
+    ],
+)
+def test_mixed_sync_async_expressions(expression, expected):
+    """Expressions mixing sync and async predicates must handle both correctly."""
+    parsed_expr = parse_boolean_expr(expression, mixed_variable_hook, operator_mapping)
+    result = parsed_expr()
+    if asyncio.iscoroutine(result):
+        assert asyncio.run(result) is expected, expression
+    else:
+        assert result is expected, expression
+
+
 @pytest.mark.xfail(reason="TODO: Optimize so that expressios are evaluated only once")
 def test_should_evaluate_values_only_once(expression, expected, caplog, hooks_called):
     caplog.set_level(logging.DEBUG, logger="tests")
diff --git a/tests/test_statemachine.py b/tests/test_statemachine.py
index 9ff82897..ea1531f7 100644
--- a/tests/test_statemachine.py
+++ b/tests/test_statemachine.py
@@ -503,3 +503,134 @@ def __bool__(self):
 
     machine.produce()
     assert model.state == "producing"
+
+
+class TestEnabledEvents:
+    def test_no_conditions_same_as_allowed_events(self, campaign_machine):
+        """Without conditions, enabled_events should match allowed_events."""
+        sm = campaign_machine()
+        assert [e.id for e in sm.enabled_events()] == [e.id for e in sm.allowed_events]
+
+    def test_passing_condition_returns_event(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="is_ready")
+
+            def is_ready(self):
+                return True
+
+        sm = MyMachine()
+        assert [e.id for e in sm.enabled_events()] == ["go"]
+
+    def test_failing_condition_excludes_event(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="is_ready")
+
+            def is_ready(self):
+                return False
+
+        sm = MyMachine()
+        assert sm.enabled_events() == []
+
+    def test_multiple_transitions_one_passes(self):
+        """Same event with multiple transitions: included if at least one passes."""
+
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State()
+            s2 = State(final=True)
+
+            go = s0.to(s1, cond="cond_false") | s0.to(s2, cond="cond_true")
+
+            def cond_false(self):
+                return False
+
+            def cond_true(self):
+                return True
+
+        sm = MyMachine()
+        assert [e.id for e in sm.enabled_events()] == ["go"]
+
+    def test_final_state_returns_empty(self, campaign_machine):
+        sm = campaign_machine()
+        sm.produce()
+        sm.deliver()
+        assert sm.enabled_events() == []
+
+    def test_kwargs_forwarded_to_conditions(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="check_value")
+
+            def check_value(self, value=0):
+                return value > 10
+
+        sm = MyMachine()
+        assert sm.enabled_events() == []
+        assert [e.id for e in sm.enabled_events(value=20)] == ["go"]
+
+    def test_condition_exception_treated_as_enabled(self):
+        """If a condition raises, the event is treated as enabled (permissive)."""
+
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, cond="bad_cond")
+
+            def bad_cond(self):
+                raise RuntimeError("boom")
+
+        sm = MyMachine()
+        assert [e.id for e in sm.enabled_events()] == ["go"]
+
+    def test_mixed_enabled_and_disabled(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State()
+            s2 = State(final=True)
+
+            go = s0.to(s1, cond="cond_true")
+            stop = s0.to(s2, cond="cond_false")
+
+            def cond_true(self):
+                return True
+
+            def cond_false(self):
+                return False
+
+        sm = MyMachine()
+        assert [e.id for e in sm.enabled_events()] == ["go"]
+
+    def test_unless_condition(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, unless="is_blocked")
+
+            def is_blocked(self):
+                return True
+
+        sm = MyMachine()
+        assert sm.enabled_events() == []
+
+    def test_unless_condition_passes(self):
+        class MyMachine(StateMachine):
+            s0 = State(initial=True)
+            s1 = State(final=True)
+
+            go = s0.to(s1, unless="is_blocked")
+
+            def is_blocked(self):
+                return False
+
+        sm = MyMachine()
+        assert [e.id for e in sm.enabled_events()] == ["go"]