diff --git a/v6d2ctx/integration/event.py b/v6d2ctx/integration/event.py
new file mode 100644
index 0000000..7f8b4fb
--- /dev/null
+++ b/v6d2ctx/integration/event.py
@@ -0,0 +1,60 @@
+__all__ = ('Event', 'SendableEvents', 'ReceivableEvents', 'Events', 'Receiver')
+
+import asyncio
+from typing import Callable, Generic, TypeVar
+
+from typing_extensions import Self
+
+from .responsetype import ResponseType
+
+
+class Event:
+    def json(self) -> ResponseType:
+        raise NotImplementedError
+
+
+T = TypeVar('T', bound=Event)
+T_co = TypeVar('T_co', bound=Event, covariant=True)
+T_contra = TypeVar('T_contra', bound=Event, contravariant=True)
+
+
+class Receiver(Generic[T_contra]):
+    def __init__(self, receive: Callable[[T_contra], None], receivers: set[Self], /) -> None:
+        self.__receive = receive
+        self.__receivers = receivers
+        self.__receiving = False
+
+    def __enter__(self) -> None:
+        self.__receivers.add(self)
+        self.__receiving = True
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.__receiving = False
+        self.__receivers.remove(self)
+
+    def receive(self, event: T_contra, /) -> None:
+        if self.__receiving:
+            self.__receive(event)
+
+
+class SendableEvents(Generic[T_contra]):
+    def send(self, event: T_contra, /) -> None:
+        raise NotImplementedError
+
+
+class ReceivableEvents(Generic[T_co]):
+    def receive(self, receive: Callable[[T_co], None], /) -> Receiver[T_co]:
+        raise NotImplementedError
+
+
+class Events(Generic[T], SendableEvents[T], ReceivableEvents[T]):
+    def __init__(self) -> None:
+        self.__receivers: set[Receiver[T]] = set()
+        self.__loop = asyncio.get_running_loop()
+
+    def send(self, event: T, /) -> None:
+        for receiver in self.__receivers:
+            self.__loop.call_soon(receiver.receive, event)
+
+    def receive(self, receive: Callable[[T], None], /) -> Receiver[T]:
+        return Receiver(receive, self.__receivers)
diff --git a/v6d2ctx/integration/responsetype.py b/v6d2ctx/integration/responsetype.py
new file mode 100644
index 0000000..2181c0d
--- /dev/null
+++ b/v6d2ctx/integration/responsetype.py
@@ -0,0 +1,17 @@
+__all__ = ('ResponseType', 'cast_to_response')
+
+from typing import Any, TypeAlias
+
+ResponseType: TypeAlias = list['ResponseType'] | dict[str, 'ResponseType'] | float | int | bool | str | None
+
+
+def cast_to_response(target: Any) -> ResponseType:
+    match target:
+        case str() | int() | float() | bool() | None:
+            return target
+        case list() | tuple():
+            return list(map(cast_to_response, target))
+        case dict():
+            return {str(key): cast_to_response(value) for key, value in target.items()}
+        case _:
+            return str(target)
diff --git a/v6d2ctx/integration/targets.py b/v6d2ctx/integration/targets.py
new file mode 100644
index 0000000..eb58130
--- /dev/null
+++ b/v6d2ctx/integration/targets.py
@@ -0,0 +1,76 @@
+__all__ = ('Targets', 'JsonLike', 'Async')
+
+import abc
+from typing import Any, Callable, Generic, TypeVar
+
+from rainbowadn.instrument import Instrumentation
+
+from .responsetype import *
+
+
+def qualname(t: type) -> str:
+    return f'{t.__module__}.{t.__qualname__}'
+
+
+T = TypeVar('T')
+
+
+class Flagful(Generic[T]):
+    def __init__(self, value: T, flags: set[object]) -> None:
+        self.value = value
+        self.flags = flags
+
+
+class Targets:
+    def __init__(self) -> None:
+        self.targets: dict[str, Flagful[tuple[Any, str]]] = {}
+        self.instrumentations: dict[str, Flagful[Callable[[Any, str], Instrumentation]]] = {}
+        self.factories: dict[tuple[str, str], Callable[[], Instrumentation]] = {}
+
+    def register_target(self, targetname: str, target: Any, methodname: str, /, *flags: object) -> None:
+        self.targets[targetname] = Flagful((target, methodname), set(flags))
+        print(f'registered          target: {targetname}')
+
+    def register_type(self, target: type, methodname: str, /, *flags: object) -> None:
+        self.register_target(f'{qualname(target)}.{methodname}', target, methodname, *flags)
+
+    def register_instance(self, target: object, methodname: str, /, *flags: object) -> None:
+        self.register_target(f'{qualname(target.__class__)}().{methodname}', target, methodname, *flags)
+
+    def register_instrumentation(
+        self,
+        instrumentationname: str,
+        instrumentation_factory: Callable[[Any, str], Instrumentation],
+        /,
+        *flags: object,
+    ) -> None:
+        self.instrumentations[instrumentationname] = Flagful(instrumentation_factory, set(flags))
+        print(f'registered instrumentation: {instrumentationname}')
+
+    def get_factory(
+        self,
+        targetname: str,
+        target: Any,
+        methodname: str,
+        instrumentationname: str,
+        instrumentation_factory: Callable[[Any, str], Instrumentation],
+        /
+    ) -> Callable[[], Instrumentation]:
+        if (targetname, instrumentationname) not in self.factories:
+            flags_required = self.instrumentations[instrumentationname].flags
+            flags_present = self.targets[targetname].flags
+            if not flags_required.issubset(flags_present):
+                raise KeyError('target lacks flags required by instrumentation')
+            self.factories[targetname, instrumentationname] = (
+                lambda: instrumentation_factory(target, methodname)
+            )
+        return self.factories[targetname, instrumentationname]
+
+
+class JsonLike(abc.ABC):
+    @abc.abstractmethod
+    def json(self) -> ResponseType:
+        raise NotImplementedError
+
+
+Async = object()