feat(event_handler): add Bedrock Agent event handler (#3285)

Co-authored-by: Heitor Lessa <lessa@amazon.com>

Author: rubenfonseca

aws_lambda_powertools/event_handler/__init__.py

@@ -11,6 +11,7 @@
     Response,
 )
 from aws_lambda_powertools.event_handler.appsync import AppSyncResolver
+from aws_lambda_powertools.event_handler.bedrock_agent import BedrockAgentResolver
 from aws_lambda_powertools.event_handler.lambda_function_url import (
     LambdaFunctionUrlResolver,
 )
@@ -22,6 +23,7 @@
     "APIGatewayHttpResolver",
     "ALBResolver",
     "ApiGatewayResolver",
+    "BedrockAgentResolver",
     "CORSConfig",
     "LambdaFunctionUrlResolver",
     "Response",

aws_lambda_powertools/event_handler/api_gateway.py

@@ -15,6 +15,7 @@
     Any,
     Callable,
     Dict,
+    Generic,
     List,
     Match,
     Optional,
@@ -23,6 +24,7 @@
     Set,
     Tuple,
     Type,
+    TypeVar,
     Union,
     cast,
 )
@@ -45,6 +47,7 @@
     ALBEvent,
     APIGatewayProxyEvent,
     APIGatewayProxyEventV2,
+    BedrockAgentEvent,
     LambdaFunctionUrlEvent,
     VPCLatticeEvent,
     VPCLatticeEventV2,
@@ -62,6 +65,8 @@
 _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION = "Successful Response"
 _ROUTE_REGEX = "^{}$"
 
+ResponseEventT = TypeVar("ResponseEventT", bound=BaseProxyEvent)
+
 if TYPE_CHECKING:
     from aws_lambda_powertools.event_handler.openapi.compat import (
         JsonSchemaValue,
@@ -85,6 +90,7 @@ class ProxyEventType(Enum):
     APIGatewayProxyEvent = "APIGatewayProxyEvent"
     APIGatewayProxyEventV2 = "APIGatewayProxyEventV2"
     ALBEvent = "ALBEvent"
+    BedrockAgentEvent = "BedrockAgentEvent"
     VPCLatticeEvent = "VPCLatticeEvent"
     VPCLatticeEventV2 = "VPCLatticeEventV2"
     LambdaFunctionUrlEvent = "LambdaFunctionUrlEvent"
@@ -208,7 +214,7 @@ def __init__(
         self,
         status_code: int,
         content_type: Optional[str] = None,
-        body: Union[str, bytes, None] = None,
+        body: Any = None,
         headers: Optional[Dict[str, Union[str, List[str]]]] = None,
         cookies: Optional[List[Cookie]] = None,
         compress: Optional[bool] = None,
@@ -235,6 +241,7 @@ def __init__(
         self.headers: Dict[str, Union[str, List[str]]] = headers if headers else {}
         self.cookies = cookies or []
         self.compress = compress
+        self.content_type = content_type
         if content_type:
             self.headers.setdefault("Content-Type", content_type)
 
@@ -689,14 +696,14 @@ def _generate_operation_id(self) -> str:
         return operation_id
 
 
-class ResponseBuilder:
+class ResponseBuilder(Generic[ResponseEventT]):
     """Internally used Response builder"""
 
     def __init__(self, response: Response, route: Optional[Route] = None):
         self.response = response
         self.route = route
 
-    def _add_cors(self, event: BaseProxyEvent, cors: CORSConfig):
+    def _add_cors(self, event: ResponseEventT, cors: CORSConfig):
         """Update headers to include the configured Access-Control headers"""
         self.response.headers.update(cors.to_dict(event.get_header_value("Origin")))
 
@@ -709,7 +716,7 @@ def _add_cache_control(self, cache_control: str):
     def _has_compression_enabled(
         route_compression: bool,
         response_compression: Optional[bool],
-        event: BaseProxyEvent,
+        event: ResponseEventT,
     ) -> bool:
         """
         Checks if compression is enabled.
@@ -722,7 +729,7 @@ def _has_compression_enabled(
             A boolean indicating whether compression is enabled or not in the route setting.
         response_compression: bool, optional
             A boolean indicating whether compression is enabled or not in the response setting.
-        event: BaseProxyEvent
+        event: ResponseEventT
             The event object containing the request details.
 
         Returns
@@ -752,7 +759,7 @@ def _compress(self):
         gzip = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16)
         self.response.body = gzip.compress(self.response.body) + gzip.flush()
 
-    def _route(self, event: BaseProxyEvent, cors: Optional[CORSConfig]):
+    def _route(self, event: ResponseEventT, cors: Optional[CORSConfig]):
         """Optionally handle any of the route's configure response handling"""
         if self.route is None:
             return
@@ -767,7 +774,7 @@ def _route(self, event: BaseProxyEvent, cors: Optional[CORSConfig]):
         ):
             self._compress()
 
-    def build(self, event: BaseProxyEvent, cors: Optional[CORSConfig] = None) -> Dict[str, Any]:
+    def build(self, event: ResponseEventT, cors: Optional[CORSConfig] = None) -> Dict[str, Any]:
         """Build the full response dict to be returned by the lambda"""
         self._route(event, cors)
 
@@ -1315,6 +1322,7 @@ def __init__(
         self._strip_prefixes = strip_prefixes
         self.context: Dict = {}  # early init as customers might add context before event resolution
         self.processed_stack_frames = []
+        self._response_builder_class = ResponseBuilder[BaseProxyEvent]
 
         # Allow for a custom serializer or a concise json serialization
         self._serializer = serializer or partial(json.dumps, separators=(",", ":"), cls=Encoder)
@@ -1784,14 +1792,17 @@ def _compile_regex(rule: str, base_regex: str = _ROUTE_REGEX):
         rule_regex: str = re.sub(_DYNAMIC_ROUTE_PATTERN, _NAMED_GROUP_BOUNDARY_PATTERN, rule)
         return re.compile(base_regex.format(rule_regex))
 
-    def _to_proxy_event(self, event: Dict) -> BaseProxyEvent:
+    def _to_proxy_event(self, event: Dict) -> BaseProxyEvent:  # noqa: PLR0911  # ignore many returns
         """Convert the event dict to the corresponding data class"""
         if self._proxy_type == ProxyEventType.APIGatewayProxyEvent:
             logger.debug("Converting event to API Gateway REST API contract")
             return APIGatewayProxyEvent(event)
         if self._proxy_type == ProxyEventType.APIGatewayProxyEventV2:
             logger.debug("Converting event to API Gateway HTTP API contract")
             return APIGatewayProxyEventV2(event)
+        if self._proxy_type == ProxyEventType.BedrockAgentEvent:
+            logger.debug("Converting event to Bedrock Agent contract")
+            return BedrockAgentEvent(event)
         if self._proxy_type == ProxyEventType.LambdaFunctionUrlEvent:
             logger.debug("Converting event to Lambda Function URL contract")
             return LambdaFunctionUrlEvent(event)
@@ -1869,9 +1880,9 @@ def _not_found(self, method: str) -> ResponseBuilder:
 
         handler = self._lookup_exception_handler(NotFoundError)
         if handler:
-            return ResponseBuilder(handler(NotFoundError()))
+            return self._response_builder_class(handler(NotFoundError()))
 
-        return ResponseBuilder(
+        return self._response_builder_class(
             Response(
                 status_code=HTTPStatus.NOT_FOUND.value,
                 content_type=content_types.APPLICATION_JSON,
@@ -1886,7 +1897,7 @@ def _call_route(self, route: Route, route_arguments: Dict[str, str]) -> Response
             # Reset Processed stack for Middleware (for debugging purposes)
             self._reset_processed_stack()
 
-            return ResponseBuilder(
+            return self._response_builder_class(
                 self._to_response(
                     route(router_middlewares=self._router_middlewares, app=self, route_arguments=route_arguments),
                 ),
@@ -1903,7 +1914,7 @@ def _call_route(self, route: Route, route_arguments: Dict[str, str]) -> Response
                 # If the user has turned on debug mode,
                 # we'll let the original exception propagate, so
                 # they get more information about what went wrong.
-                return ResponseBuilder(
+                return self._response_builder_class(
                     Response(
                         status_code=500,
                         content_type=content_types.TEXT_PLAIN,
@@ -1942,12 +1953,12 @@ def _call_exception_handler(self, exp: Exception, route: Route) -> Optional[Resp
         handler = self._lookup_exception_handler(type(exp))
         if handler:
             try:
-                return ResponseBuilder(handler(exp), route)
+                return self._response_builder_class(handler(exp), route)
             except ServiceError as service_error:
                 exp = service_error
 
         if isinstance(exp, ServiceError):
-            return ResponseBuilder(
+            return self._response_builder_class(
                 Response(
                     status_code=exp.status_code,
                     content_type=content_types.APPLICATION_JSON,

aws_lambda_powertools/event_handler/bedrock_agent.py

@@ -0,0 +1,77 @@
+from typing import Any, Dict
+
+from typing_extensions import override
+
+from aws_lambda_powertools.event_handler import ApiGatewayResolver
+from aws_lambda_powertools.event_handler.api_gateway import (
+    ProxyEventType,
+    ResponseBuilder,
+)
+from aws_lambda_powertools.utilities.data_classes import BedrockAgentEvent
+
+
+class BedrockResponseBuilder(ResponseBuilder):
+    """
+    Bedrock Response Builder. This builds the response dict to be returned by Lambda when using Bedrock Agents.
+
+    Since the payload format is different from the standard API Gateway Proxy event, we override the build method.
+    """
+
+    @override
+    def build(self, event: BedrockAgentEvent, *args) -> Dict[str, Any]:
+        """Build the full response dict to be returned by the lambda"""
+        self._route(event, None)
+
+        return {
+            "messageVersion": "1.0",
+            "response": {
+                "actionGroup": event.action_group,
+                "apiPath": event.api_path,
+                "httpMethod": event.http_method,
+                "httpStatusCode": self.response.status_code,
+                "responseBody": {
+                    self.response.content_type: {
+                        "body": self.response.body,
+                    },
+                },
+            },
+        }
+
+
+class BedrockAgentResolver(ApiGatewayResolver):
+    """Bedrock Agent Resolver
+
+    See https://aws.amazon.com/bedrock/agents/ for more information.
+
+    Examples
+    --------
+    Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
+
+    ```python
+    from aws_lambda_powertools import Tracer
+    from aws_lambda_powertools.event_handler import BedrockAgentResolver
+
+    tracer = Tracer()
+    app = BedrockAgentResolver()
+
+    @app.get("/claims")
+    def simple_get():
+        return "You have 3 claims"
+
+    @tracer.capture_lambda_handler
+    def lambda_handler(event, context):
+        return app.resolve(event, context)
+    """
+
+    current_event: BedrockAgentEvent
+
+    def __init__(self, debug: bool = False, enable_validation: bool = True):
+        super().__init__(
+            proxy_type=ProxyEventType.BedrockAgentEvent,
+            cors=None,
+            debug=debug,
+            serializer=None,
+            strip_prefixes=None,
+            enable_validation=enable_validation,
+        )
+        self._response_builder_class = BedrockResponseBuilder

aws_lambda_powertools/utilities/data_classes/bedrock_agent_event.py

@@ -1,6 +1,6 @@
 from typing import Dict, List, Optional
 
-from aws_lambda_powertools.utilities.data_classes.common import DictWrapper
+from aws_lambda_powertools.utilities.data_classes.common import BaseProxyEvent, DictWrapper
 
 
 class BedrockAgentInfo(DictWrapper):
@@ -47,7 +47,7 @@ def content(self) -> Dict[str, BedrockAgentRequestMedia]:
         return {k: BedrockAgentRequestMedia(v) for k, v in self["content"].items()}
 
 
-class BedrockAgentEvent(DictWrapper):
+class BedrockAgentEvent(BaseProxyEvent):
     """
     Bedrock Agent input event
 
@@ -97,3 +97,8 @@ def session_attributes(self) -> Dict[str, str]:
     @property
     def prompt_session_attributes(self) -> Dict[str, str]:
         return self["promptSessionAttributes"]
+
+    # For compatibility with BaseProxyEvent
+    @property
+    def path(self) -> str:
+        return self["apiPath"]