diff --git a/.changes/unreleased/Features-20240808-194933.yaml b/.changes/unreleased/Features-20240808-194933.yaml
new file mode 100644
index 0000000..1dfd106
--- /dev/null
+++ b/.changes/unreleased/Features-20240808-194933.yaml
@@ -0,0 +1,6 @@
+kind: Features
+body: Add Behavior Flag Framework
+time: 2024-08-08T19:49:33.738569-04:00
+custom:
+  Author: mikealfare
+  Issue: "178"
diff --git a/.gitignore b/.gitignore
index 5ad1a6c..85795bd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -158,3 +158,6 @@ cython_debug/
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 .idea/
+
+# VSCode
+.vscode/
diff --git a/dbt_common/__about__.py b/dbt_common/__about__.py
index a55413d..f15b401 100644
--- a/dbt_common/__about__.py
+++ b/dbt_common/__about__.py
@@ -1 +1 @@
-version = "1.7.0"
+version = "1.8.0a1"
diff --git a/dbt_common/behavior_flags.py b/dbt_common/behavior_flags.py
new file mode 100644
index 0000000..a647ed7
--- /dev/null
+++ b/dbt_common/behavior_flags.py
@@ -0,0 +1,125 @@
+import inspect
+from typing import Any, Dict, List, TypedDict
+
+try:
+    from typing import NotRequired
+except ImportError:
+    # NotRequired was introduced in Python 3.11
+    # This is the suggested way to implement a TypedDict with optional arguments
+    from typing import Optional as NotRequired
+
+from dbt_common.events.functions import fire_event
+from dbt_common.events.types import BehaviorDeprecationEvent
+from dbt_common.exceptions import CompilationError
+
+
+class BehaviorFlag(TypedDict):
+    """
+    Configuration used to create a BehaviorFlagRendered instance
+
+    Args:
+        name: the name of the behavior flag
+        default: default setting, starts as False, becomes True after a bake-in period
+        deprecation_version: the version when the default will change to True
+        deprecation_message: an additional message to send when the flag evaluates to False
+        docs_url: the url to the relevant docs on docs.getdbt.com
+    """
+
+    name: str
+    default: bool
+    source: NotRequired[str]
+    deprecation_version: NotRequired[str]
+    deprecation_message: NotRequired[str]
+    docs_url: NotRequired[str]
+
+
+class BehaviorFlagRendered:
+    """
+    A rendered behavior flag that gets used throughout dbt packages
+
+    Args:
+        flag: the configuration for the behavior flag
+        user_overrides: a set of user settings, one of which may be an override on this behavior flag
+    """
+
+    def __init__(self, flag: BehaviorFlag, user_overrides: Dict[str, Any]) -> None:
+        self.name = flag["name"]
+        self.setting = user_overrides.get(flag["name"], flag["default"])
+        self.deprecation_event = self._deprecation_event(flag)
+
+    @property
+    def setting(self) -> bool:
+        if self._setting is False:
+            fire_event(self.deprecation_event)
+        return self._setting
+
+    @setting.setter
+    def setting(self, value: bool) -> None:
+        self._setting = value
+
+    @property
+    def no_warn(self) -> bool:
+        return self._setting
+
+    def _deprecation_event(self, flag: BehaviorFlag) -> BehaviorDeprecationEvent:
+        return BehaviorDeprecationEvent(
+            flag_name=flag["name"],
+            flag_source=flag.get("source", self._default_source()),
+            deprecation_version=flag.get("deprecation_version"),
+            deprecation_message=flag.get("deprecation_message"),
+            docs_url=flag.get("docs_url"),
+        )
+
+    @staticmethod
+    def _default_source() -> str:
+        """
+        If the maintainer did not provide a source, default to the module that called this class.
+        For adapters, this will likely be `dbt.adapters.<foo>.impl` for `dbt-foo`.
+        """
+        for frame in inspect.stack():
+            if module := inspect.getmodule(frame[0]):
+                if module.__name__ != __name__:
+                    return module.__name__
+        return "Unknown"
+
+    def __bool__(self) -> bool:
+        return self.setting
+
+
+class Behavior:
+    """
+    A collection of behavior flags
+
+    This is effectively a dictionary that supports dot notation for easy reference, e.g.:
+        ```python
+        if adapter.behavior.my_flag:
+            ...
+
+        if adapter.behavior.my_flag.no_warn:  # this will not fire the deprecation event
+            ...
+        ```
+        ```jinja
+        {% if adapter.behavior.my_flag %}
+            ...
+        {% endif %}
+
+        {% if adapter.behavior.my_flag.no_warn %}  {# this will not fire the deprecation event #}
+            ...
+        {% endif %}
+        ```
+
+    Args:
+        flags: a list of configurations, one for each behavior flag
+        user_overrides: a set of user settings, which may include overrides on one or more of the behavior flags
+    """
+
+    _flags: List[BehaviorFlagRendered]
+
+    def __init__(self, flags: List[BehaviorFlag], user_overrides: Dict[str, Any]) -> None:
+        self._flags = [BehaviorFlagRendered(flag, user_overrides) for flag in flags]
+
+    def __getattr__(self, name: str) -> BehaviorFlagRendered:
+        for flag in self._flags:
+            if flag.name == name:
+                return flag
+        raise CompilationError(f"The flag {name} has not be registered.")
diff --git a/dbt_common/events/types.proto b/dbt_common/events/types.proto
index 3ca066d..d72d6b2 100644
--- a/dbt_common/events/types.proto
+++ b/dbt_common/events/types.proto
@@ -23,6 +23,22 @@ message GenericMessage {
     EventInfo info = 1;
 }
 
+// D - Deprecations
+
+// D018
+message BehaviorDeprecationEvent {
+    string flag_name = 1;
+    string flag_source = 2;
+    string deprecation_version = 3;
+    string deprecation_message = 4;
+    string docs_url = 5;
+}
+
+message BehaviorDeprecationEventMsg {
+    EventInfo info = 1;
+    BehaviorDeprecationEvent data = 2;
+}
+
 // M - Deps generation
 
 // M020
diff --git a/dbt_common/events/types.py b/dbt_common/events/types.py
index b60f9e1..02fc3ee 100644
--- a/dbt_common/events/types.py
+++ b/dbt_common/events/types.py
@@ -1,7 +1,11 @@
+from typing import Optional
+
 from dbt_common.events.base_types import (
     DebugLevel,
     InfoLevel,
+    WarnLevel,
 )
+from dbt_common.ui import warning_tag
 
 
 # The classes in this file represent the data necessary to describe a
@@ -28,6 +32,41 @@
 #
 # The basic idea is that event codes roughly translate to the natural order of running a dbt task
 
+
+# =======================================================
+# D - Deprecations
+# =======================================================
+
+
+class BehaviorDeprecationEvent(WarnLevel):
+    flag_name: str
+    flag_source: str
+    deprecation_version: Optional[str]
+    deprecation_message: Optional[str]
+    docs_url: Optional[str]
+
+    def code(self) -> str:
+        return "D018"
+
+    def message(self) -> str:
+        msg = f"The legacy behavior controlled by `{self.flag_name}` is deprecated.\n"
+
+        if self.deprecation_version:
+            msg = (
+                f"The legacy behavior is expected to be retired in `{self.deprecation_version}`.\n"
+            )
+
+        msg += f"The new behavior can be turned on by setting `flags.{self.flag_name}` to `True` in `dbt_project.yml`.\n"
+
+        if self.deprecation_message:
+            msg += f"{self.deprecation_message}.\n"
+
+        docs_url = self.docs_url or f"https://docs.getdbt.com/search?q={self.flag_name}"
+        msg += f"Visit {docs_url} for more information."
+
+        return warning_tag(msg)
+
+
 # =======================================================
 # M - Deps generation
 # =======================================================
diff --git a/dbt_common/events/types_pb2.py b/dbt_common/events/types_pb2.py
index 2112273..6b3afc5 100644
--- a/dbt_common/events/types_pb2.py
+++ b/dbt_common/events/types_pb2.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # source: types.proto
-# Protobuf Python Version: 5.26.1
+# Protobuf Python Version: 4.25.2
 """Generated protocol buffer code."""
 from google.protobuf import descriptor as _descriptor
 from google.protobuf import descriptor_pool as _descriptor_pool
@@ -15,14 +15,14 @@
 from google.protobuf import timestamp_pb2 as google_dot_protobuf_dot_timestamp__pb2
 
 
-DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x0btypes.proto\x12\x0bproto_types\x1a\x1fgoogle/protobuf/timestamp.proto\"\x91\x02\n\tEventInfo\x12\x0c\n\x04name\x18\x01 \x01(\t\x12\x0c\n\x04\x63ode\x18\x02 \x01(\t\x12\x0b\n\x03msg\x18\x03 \x01(\t\x12\r\n\x05level\x18\x04 \x01(\t\x12\x15\n\rinvocation_id\x18\x05 \x01(\t\x12\x0b\n\x03pid\x18\x06 \x01(\x05\x12\x0e\n\x06thread\x18\x07 \x01(\t\x12&\n\x02ts\x18\x08 \x01(\x0b\x32\x1a.google.protobuf.Timestamp\x12\x30\n\x05\x65xtra\x18\t \x03(\x0b\x32!.proto_types.EventInfo.ExtraEntry\x12\x10\n\x08\x63\x61tegory\x18\n \x01(\t\x1a,\n\nExtraEntry\x12\x0b\n\x03key\x18\x01 \x01(\t\x12\r\n\x05value\x18\x02 \x01(\t:\x02\x38\x01\"6\n\x0eGenericMessage\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\"1\n\x11RetryExternalCall\x12\x0f\n\x07\x61ttempt\x18\x01 \x01(\x05\x12\x0b\n\x03max\x18\x02 \x01(\x05\"j\n\x14RetryExternalCallMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12,\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x1e.proto_types.RetryExternalCall\"#\n\x14RecordRetryException\x12\x0b\n\x03\x65xc\x18\x01 \x01(\t\"p\n\x17RecordRetryExceptionMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12/\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32!.proto_types.RecordRetryException\"@\n\x13SystemCouldNotWrite\x12\x0c\n\x04path\x18\x01 \x01(\t\x12\x0e\n\x06reason\x18\x02 \x01(\t\x12\x0b\n\x03\x65xc\x18\x03 \x01(\t\"n\n\x16SystemCouldNotWriteMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12.\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32 .proto_types.SystemCouldNotWrite\"!\n\x12SystemExecutingCmd\x12\x0b\n\x03\x63md\x18\x01 \x03(\t\"l\n\x15SystemExecutingCmdMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12-\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x1f.proto_types.SystemExecutingCmd\"\x1c\n\x0cSystemStdOut\x12\x0c\n\x04\x62msg\x18\x01 \x01(\t\"`\n\x0fSystemStdOutMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\'\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x19.proto_types.SystemStdOut\"\x1c\n\x0cSystemStdErr\x12\x0c\n\x04\x62msg\x18\x01 \x01(\t\"`\n\x0fSystemStdErrMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\'\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x19.proto_types.SystemStdErr\",\n\x16SystemReportReturnCode\x12\x12\n\nreturncode\x18\x01 \x01(\x05\"t\n\x19SystemReportReturnCodeMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\x31\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32#.proto_types.SystemReportReturnCode\"\x19\n\nFormatting\x12\x0b\n\x03msg\x18\x01 \x01(\t\"\\\n\rFormattingMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12%\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x17.proto_types.Formatting\"\x13\n\x04Note\x12\x0b\n\x03msg\x18\x01 \x01(\t\"P\n\x07NoteMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\x1f\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x11.proto_types.Note\"\x19\n\nPrintEvent\x12\x0b\n\x03msg\x18\x01 \x01(\t\"\\\n\rPrintEventMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12%\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x17.proto_types.PrintEventb\x06proto3')
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x0btypes.proto\x12\x0bproto_types\x1a\x1fgoogle/protobuf/timestamp.proto\"\x91\x02\n\tEventInfo\x12\x0c\n\x04name\x18\x01 \x01(\t\x12\x0c\n\x04\x63ode\x18\x02 \x01(\t\x12\x0b\n\x03msg\x18\x03 \x01(\t\x12\r\n\x05level\x18\x04 \x01(\t\x12\x15\n\rinvocation_id\x18\x05 \x01(\t\x12\x0b\n\x03pid\x18\x06 \x01(\x05\x12\x0e\n\x06thread\x18\x07 \x01(\t\x12&\n\x02ts\x18\x08 \x01(\x0b\x32\x1a.google.protobuf.Timestamp\x12\x30\n\x05\x65xtra\x18\t \x03(\x0b\x32!.proto_types.EventInfo.ExtraEntry\x12\x10\n\x08\x63\x61tegory\x18\n \x01(\t\x1a,\n\nExtraEntry\x12\x0b\n\x03key\x18\x01 \x01(\t\x12\r\n\x05value\x18\x02 \x01(\t:\x02\x38\x01\"6\n\x0eGenericMessage\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\"\x8e\x01\n\x18\x42\x65haviorDeprecationEvent\x12\x11\n\tflag_name\x18\x01 \x01(\t\x12\x13\n\x0b\x66lag_source\x18\x02 \x01(\t\x12\x1b\n\x13\x64\x65precation_version\x18\x03 \x01(\t\x12\x1b\n\x13\x64\x65precation_message\x18\x04 \x01(\t\x12\x10\n\x08\x64ocs_url\x18\x05 \x01(\t\"x\n\x1b\x42\x65haviorDeprecationEventMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\x33\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32%.proto_types.BehaviorDeprecationEvent\"1\n\x11RetryExternalCall\x12\x0f\n\x07\x61ttempt\x18\x01 \x01(\x05\x12\x0b\n\x03max\x18\x02 \x01(\x05\"j\n\x14RetryExternalCallMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12,\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x1e.proto_types.RetryExternalCall\"#\n\x14RecordRetryException\x12\x0b\n\x03\x65xc\x18\x01 \x01(\t\"p\n\x17RecordRetryExceptionMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12/\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32!.proto_types.RecordRetryException\"@\n\x13SystemCouldNotWrite\x12\x0c\n\x04path\x18\x01 \x01(\t\x12\x0e\n\x06reason\x18\x02 \x01(\t\x12\x0b\n\x03\x65xc\x18\x03 \x01(\t\"n\n\x16SystemCouldNotWriteMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12.\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32 .proto_types.SystemCouldNotWrite\"!\n\x12SystemExecutingCmd\x12\x0b\n\x03\x63md\x18\x01 \x03(\t\"l\n\x15SystemExecutingCmdMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12-\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x1f.proto_types.SystemExecutingCmd\"\x1c\n\x0cSystemStdOut\x12\x0c\n\x04\x62msg\x18\x01 \x01(\t\"`\n\x0fSystemStdOutMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\'\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x19.proto_types.SystemStdOut\"\x1c\n\x0cSystemStdErr\x12\x0c\n\x04\x62msg\x18\x01 \x01(\t\"`\n\x0fSystemStdErrMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\'\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x19.proto_types.SystemStdErr\",\n\x16SystemReportReturnCode\x12\x12\n\nreturncode\x18\x01 \x01(\x05\"t\n\x19SystemReportReturnCodeMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\x31\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32#.proto_types.SystemReportReturnCode\"\x19\n\nFormatting\x12\x0b\n\x03msg\x18\x01 \x01(\t\"\\\n\rFormattingMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12%\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x17.proto_types.Formatting\"\x13\n\x04Note\x12\x0b\n\x03msg\x18\x01 \x01(\t\"P\n\x07NoteMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12\x1f\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x11.proto_types.Note\"\x19\n\nPrintEvent\x12\x0b\n\x03msg\x18\x01 \x01(\t\"\\\n\rPrintEventMsg\x12$\n\x04info\x18\x01 \x01(\x0b\x32\x16.proto_types.EventInfo\x12%\n\x04\x64\x61ta\x18\x02 \x01(\x0b\x32\x17.proto_types.PrintEventb\x06proto3')
 
 _globals = globals()
 _builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, _globals)
 _builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'types_pb2', _globals)
-if not _descriptor._USE_C_DESCRIPTORS:
-  DESCRIPTOR._loaded_options = None
-  _globals['_EVENTINFO_EXTRAENTRY']._loaded_options = None
+if _descriptor._USE_C_DESCRIPTORS == False:
+  DESCRIPTOR._options = None
+  _globals['_EVENTINFO_EXTRAENTRY']._options = None
   _globals['_EVENTINFO_EXTRAENTRY']._serialized_options = b'8\001'
   _globals['_EVENTINFO']._serialized_start=62
   _globals['_EVENTINFO']._serialized_end=335
@@ -30,44 +30,48 @@
   _globals['_EVENTINFO_EXTRAENTRY']._serialized_end=335
   _globals['_GENERICMESSAGE']._serialized_start=337
   _globals['_GENERICMESSAGE']._serialized_end=391
-  _globals['_RETRYEXTERNALCALL']._serialized_start=393
-  _globals['_RETRYEXTERNALCALL']._serialized_end=442
-  _globals['_RETRYEXTERNALCALLMSG']._serialized_start=444
-  _globals['_RETRYEXTERNALCALLMSG']._serialized_end=550
-  _globals['_RECORDRETRYEXCEPTION']._serialized_start=552
-  _globals['_RECORDRETRYEXCEPTION']._serialized_end=587
-  _globals['_RECORDRETRYEXCEPTIONMSG']._serialized_start=589
-  _globals['_RECORDRETRYEXCEPTIONMSG']._serialized_end=701
-  _globals['_SYSTEMCOULDNOTWRITE']._serialized_start=703
-  _globals['_SYSTEMCOULDNOTWRITE']._serialized_end=767
-  _globals['_SYSTEMCOULDNOTWRITEMSG']._serialized_start=769
-  _globals['_SYSTEMCOULDNOTWRITEMSG']._serialized_end=879
-  _globals['_SYSTEMEXECUTINGCMD']._serialized_start=881
-  _globals['_SYSTEMEXECUTINGCMD']._serialized_end=914
-  _globals['_SYSTEMEXECUTINGCMDMSG']._serialized_start=916
-  _globals['_SYSTEMEXECUTINGCMDMSG']._serialized_end=1024
-  _globals['_SYSTEMSTDOUT']._serialized_start=1026
-  _globals['_SYSTEMSTDOUT']._serialized_end=1054
-  _globals['_SYSTEMSTDOUTMSG']._serialized_start=1056
-  _globals['_SYSTEMSTDOUTMSG']._serialized_end=1152
-  _globals['_SYSTEMSTDERR']._serialized_start=1154
-  _globals['_SYSTEMSTDERR']._serialized_end=1182
-  _globals['_SYSTEMSTDERRMSG']._serialized_start=1184
-  _globals['_SYSTEMSTDERRMSG']._serialized_end=1280
-  _globals['_SYSTEMREPORTRETURNCODE']._serialized_start=1282
-  _globals['_SYSTEMREPORTRETURNCODE']._serialized_end=1326
-  _globals['_SYSTEMREPORTRETURNCODEMSG']._serialized_start=1328
-  _globals['_SYSTEMREPORTRETURNCODEMSG']._serialized_end=1444
-  _globals['_FORMATTING']._serialized_start=1446
-  _globals['_FORMATTING']._serialized_end=1471
-  _globals['_FORMATTINGMSG']._serialized_start=1473
-  _globals['_FORMATTINGMSG']._serialized_end=1565
-  _globals['_NOTE']._serialized_start=1567
-  _globals['_NOTE']._serialized_end=1586
-  _globals['_NOTEMSG']._serialized_start=1588
-  _globals['_NOTEMSG']._serialized_end=1668
-  _globals['_PRINTEVENT']._serialized_start=1670
-  _globals['_PRINTEVENT']._serialized_end=1695
-  _globals['_PRINTEVENTMSG']._serialized_start=1697
-  _globals['_PRINTEVENTMSG']._serialized_end=1789
+  _globals['_BEHAVIORDEPRECATIONEVENT']._serialized_start=394
+  _globals['_BEHAVIORDEPRECATIONEVENT']._serialized_end=536
+  _globals['_BEHAVIORDEPRECATIONEVENTMSG']._serialized_start=538
+  _globals['_BEHAVIORDEPRECATIONEVENTMSG']._serialized_end=658
+  _globals['_RETRYEXTERNALCALL']._serialized_start=660
+  _globals['_RETRYEXTERNALCALL']._serialized_end=709
+  _globals['_RETRYEXTERNALCALLMSG']._serialized_start=711
+  _globals['_RETRYEXTERNALCALLMSG']._serialized_end=817
+  _globals['_RECORDRETRYEXCEPTION']._serialized_start=819
+  _globals['_RECORDRETRYEXCEPTION']._serialized_end=854
+  _globals['_RECORDRETRYEXCEPTIONMSG']._serialized_start=856
+  _globals['_RECORDRETRYEXCEPTIONMSG']._serialized_end=968
+  _globals['_SYSTEMCOULDNOTWRITE']._serialized_start=970
+  _globals['_SYSTEMCOULDNOTWRITE']._serialized_end=1034
+  _globals['_SYSTEMCOULDNOTWRITEMSG']._serialized_start=1036
+  _globals['_SYSTEMCOULDNOTWRITEMSG']._serialized_end=1146
+  _globals['_SYSTEMEXECUTINGCMD']._serialized_start=1148
+  _globals['_SYSTEMEXECUTINGCMD']._serialized_end=1181
+  _globals['_SYSTEMEXECUTINGCMDMSG']._serialized_start=1183
+  _globals['_SYSTEMEXECUTINGCMDMSG']._serialized_end=1291
+  _globals['_SYSTEMSTDOUT']._serialized_start=1293
+  _globals['_SYSTEMSTDOUT']._serialized_end=1321
+  _globals['_SYSTEMSTDOUTMSG']._serialized_start=1323
+  _globals['_SYSTEMSTDOUTMSG']._serialized_end=1419
+  _globals['_SYSTEMSTDERR']._serialized_start=1421
+  _globals['_SYSTEMSTDERR']._serialized_end=1449
+  _globals['_SYSTEMSTDERRMSG']._serialized_start=1451
+  _globals['_SYSTEMSTDERRMSG']._serialized_end=1547
+  _globals['_SYSTEMREPORTRETURNCODE']._serialized_start=1549
+  _globals['_SYSTEMREPORTRETURNCODE']._serialized_end=1593
+  _globals['_SYSTEMREPORTRETURNCODEMSG']._serialized_start=1595
+  _globals['_SYSTEMREPORTRETURNCODEMSG']._serialized_end=1711
+  _globals['_FORMATTING']._serialized_start=1713
+  _globals['_FORMATTING']._serialized_end=1738
+  _globals['_FORMATTINGMSG']._serialized_start=1740
+  _globals['_FORMATTINGMSG']._serialized_end=1832
+  _globals['_NOTE']._serialized_start=1834
+  _globals['_NOTE']._serialized_end=1853
+  _globals['_NOTEMSG']._serialized_start=1855
+  _globals['_NOTEMSG']._serialized_end=1935
+  _globals['_PRINTEVENT']._serialized_start=1937
+  _globals['_PRINTEVENT']._serialized_end=1962
+  _globals['_PRINTEVENTMSG']._serialized_start=1964
+  _globals['_PRINTEVENTMSG']._serialized_end=2056
 # @@protoc_insertion_point(module_scope)
diff --git a/pyproject.toml b/pyproject.toml
index ba30643..2e40385 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -127,9 +127,10 @@ exclude = [
     "dbt_common/events/types_pb2.py",
     "venv",
     ".venv",
-    "env*"
+    "env*",
+    ".hatch/*",
 ]
-per-file-ignores = ["*/__init__.py: F401"]
+per-file-ignores = ["*/__init__.py: F401", "*/conftest.py: F401"]
 docstring-convention = "google"
 
 [tool.mypy]
@@ -140,6 +141,7 @@ show_error_codes = true
 disable_error_code = "attr-defined"  # TODO: revisit once other mypy errors resolved
 disallow_untyped_defs = false # TODO: add type annotations everywhere
 warn_redundant_casts = true
+ignore_missing_imports = true
 exclude = [
     "dbt_common/events/types_pb2.py",
     "env*",
diff --git a/tests/unit/conftest.py b/tests/unit/conftest.py
new file mode 100644
index 0000000..c553bf5
--- /dev/null
+++ b/tests/unit/conftest.py
@@ -0,0 +1 @@
+from tests.unit.utils import event_catcher
diff --git a/tests/unit/test_behavior_flags.py b/tests/unit/test_behavior_flags.py
new file mode 100644
index 0000000..256b744
--- /dev/null
+++ b/tests/unit/test_behavior_flags.py
@@ -0,0 +1,116 @@
+import pytest
+
+from dbt_common.behavior_flags import Behavior
+from dbt_common.exceptions.base import CompilationError
+
+
+def test_behavior_default():
+    behavior = Behavior(
+        [
+            {"name": "default_false_flag", "default": False},
+            {"name": "default_true_flag", "default": True},
+        ],
+        {},
+    )
+
+    assert behavior.default_false_flag.setting is False
+    assert behavior.default_true_flag.setting is True
+
+
+def test_behavior_user_override():
+    behavior = Behavior(
+        [
+            {"name": "flag_default_false", "default": False},
+            {"name": "flag_default_false_override_false", "default": False},
+            {"name": "flag_default_false_override_true", "default": False},
+            {"name": "flag_default_true", "default": True},
+            {"name": "flag_default_true_override_false", "default": True},
+            {"name": "flag_default_true_override_true", "default": True},
+        ],
+        {
+            "flag_default_false_override_false": False,
+            "flag_default_false_override_true": True,
+            "flag_default_true_override_false": False,
+            "flag_default_true_override_true": True,
+        },
+    )
+
+    assert behavior.flag_default_false.setting is False
+    assert behavior.flag_default_false_override_false.setting is False
+    assert behavior.flag_default_false_override_true.setting is True
+    assert behavior.flag_default_true.setting is True
+    assert behavior.flag_default_true_override_false.setting is False
+    assert behavior.flag_default_true_override_true.setting is True
+
+
+def test_behavior_unregistered_flag_raises_correct_exception():
+    behavior = Behavior(
+        [
+            {"name": "behavior_flag_exists", "default": False},
+        ],
+        {},
+    )
+
+    assert behavior.behavior_flag_exists.setting is False
+    with pytest.raises(CompilationError):
+        assert behavior.behavior_flag_does_not_exist
+
+
+def test_behavior_flag_can_be_used_as_conditional():
+    behavior = Behavior(
+        [
+            {"name": "flag_false", "default": False},
+            {"name": "flag_true", "default": True},
+        ],
+        {},
+    )
+
+    assert False if behavior.flag_false else True
+    assert True if behavior.flag_true else False
+
+
+def test_behavior_flags_emit_deprecation_event_on_evaluation(event_catcher) -> None:
+    behavior = Behavior(
+        [
+            {"name": "flag_false", "default": False},
+            {"name": "flag_true", "default": True},
+        ],
+        {},
+    )
+
+    # trigger the evaluation, no event should fire
+    if behavior.flag_true:
+        pass
+    assert len(event_catcher.caught_events) == 0
+
+    # trigger the evaluation, an event should fire
+    if behavior.flag_false:
+        pass
+    assert len(event_catcher.caught_events) == 1
+
+
+def test_behavior_flags_emit_correct_deprecation_event(event_catcher) -> None:
+    behavior = Behavior([{"name": "flag_false", "default": False}], {})
+
+    # trigger the evaluation
+    if behavior.flag_false:
+        pass
+
+    msg = event_catcher.caught_events[0]
+    assert msg.info.name == "BehaviorDeprecationEvent"
+    assert msg.data.flag_name == "flag_false"
+    assert msg.data.flag_source == __name__  # defaults to the calling module
+
+
+def test_behavior_flags_no_deprecation_event_on_no_warn(event_catcher) -> None:
+    behavior = Behavior([{"name": "flag_false", "default": False}], {})
+
+    # trigger the evaluation with no_warn, no event should fire
+    if behavior.flag_false.no_warn:
+        pass
+    assert len(event_catcher.caught_events) == 0
+
+    # trigger the evaluation, an event should fire
+    if behavior.flag_false:
+        pass
+    assert len(event_catcher.caught_events) == 1
diff --git a/tests/unit/test_events.py b/tests/unit/test_events.py
index 800790d..9a9abc6 100644
--- a/tests/unit/test_events.py
+++ b/tests/unit/test_events.py
@@ -61,6 +61,8 @@ class TestEventJSONSerialization:
     SAMPLE_VALUES = [
         # N.B. Events instantiated here include the module prefix in order to
         # avoid having the entire list twice in the code.
+        # D - Deprecations ======================
+        types.BehaviorDeprecationEvent(flag_name="Do you have a flag?", flag_source="dbt_common"),
         # M - Deps generation ======================
         types.RetryExternalCall(attempt=0, max=0),
         types.RecordRetryException(exc=""),
diff --git a/tests/unit/utils.py b/tests/unit/utils.py
index c79ecc5..3a46a2c 100644
--- a/tests/unit/utils.py
+++ b/tests/unit/utils.py
@@ -1,7 +1,12 @@
 from dataclasses import dataclass, field
 from typing import List
 
+import pytest
+from pytest_mock import MockerFixture
+
 from dbt_common.events.base_types import EventMsg
+from dbt_common.events.event_manager import EventManager
+from dbt_common.events.event_manager_client import add_callback_to_manager
 
 
 @dataclass
@@ -10,3 +15,12 @@ class EventCatcher:
 
     def catch(self, event: EventMsg) -> None:
         self.caught_events.append(event)
+
+
+@pytest.fixture(scope="function")
+def event_catcher(mocker: MockerFixture) -> EventCatcher:
+    # mock out the global event manager so the callback doesn't get added to all other tests
+    mocker.patch("dbt_common.events.event_manager_client._EVENT_MANAGER", EventManager())
+    catcher = EventCatcher()
+    add_callback_to_manager(catcher.catch)
+    return catcher