wip

Author: guglielmo-san

src/a2a/compat/v0_3/grpc_handler.py

@@ -23,7 +23,7 @@
 from a2a.server.context import ServerCallContext
 from a2a.server.request_handlers.grpc_handler import (
     _ERROR_CODE_MAP,
-    GrpcUserBuilder,
+    GrpcContextBuilder,
     build_grpc_server_call_context,
     default_grpc_user_builder,
 )
@@ -45,7 +45,7 @@ def __init__(
         self,
         agent_card: AgentCard,
         request_handler: RequestHandler,
-        user_builder: GrpcUserBuilder | None = None,
+       context_builder: GrpcContextBuilder | None = None,
         card_modifier: Callable[[AgentCard], Awaitable[AgentCard] | AgentCard]
         | None = None,
     ):
@@ -55,14 +55,14 @@ def __init__(
             agent_card: The AgentCard describing the agent's capabilities (v1.0).
             request_handler: The underlying `RequestHandler` instance to
                              delegate requests to.
-            user_builder: Optional custom user builder to extract user from the
+           context_builder: Optional custom user builder to extract user from the
                           gRPC context.
             card_modifier: An optional callback to dynamically modify the public
               agent card before it is served.
         """
         self.agent_card = agent_card
         self.handler03 = RequestHandler03(request_handler=request_handler)
-        self.user_builder = user_builder or default_grpc_user_builder
+        self.user_builder =context_builder or default_grpc_user_builder
         self.card_modifier = card_modifier
 
     async def _handle_unary(

src/a2a/compat/v0_3/jsonrpc_adapter.py

@@ -38,9 +38,8 @@
     JSONRPCError as CoreJSONRPCError,
 )
 from a2a.server.routes.common import (
-    UserBuilder,
-    build_server_call_context,
-    default_user_builder,
+    ContextBuilder,
+    DefaultContextBuilder,
 )
 from a2a.utils import constants
 from a2a.utils.errors import ExtendedAgentCardNotConfiguredError
@@ -71,7 +70,7 @@ def __init__(  # noqa: PLR0913
         agent_card: 'AgentCard',
         http_handler: 'RequestHandler',
         extended_agent_card: 'AgentCard | None' = None,
-        user_builder: 'UserBuilder | None' = None,
+        context_builder: 'ContextBuilder | None' = None,
         card_modifier: 'Callable[[AgentCard], Awaitable[AgentCard] | AgentCard] | None' = None,
         extended_card_modifier: 'Callable[[AgentCard, ServerCallContext], Awaitable[AgentCard] | AgentCard] | None' = None,
     ):
@@ -82,7 +81,7 @@ def __init__(  # noqa: PLR0913
         self.handler = RequestHandler03(
             request_handler=http_handler,
         )
-        self._user_builder = user_builder or default_user_builder
+        self._context_builder = context_builder or DefaultContextBuilder()
 
     def supports_method(self, method: str) -> bool:
         """Returns True if the v0.3 adapter supports the given method name."""
@@ -130,9 +129,7 @@ async def handle_request(
                     CoreInvalidRequestError(data=str(e)),
                 )
 
-            call_context = build_server_call_context(
-                request, self._user_builder
-            )
+            call_context = self._context_builder.build(request)
             call_context.tenant = (
                 getattr(specific_request.params, 'tenant', '')
                 if hasattr(specific_request, 'params')

src/a2a/compat/v0_3/rest_adapter.py

@@ -35,7 +35,7 @@
 from a2a.compat.v0_3.rest_handler import REST03Handler
 from a2a.server.context import ServerCallContext
 from a2a.server.routes.common import (
-    UserBuilder,
+    ContextBuilder,
     build_server_call_context,
     default_user_builder,
 )
@@ -64,7 +64,7 @@ def __init__(  # noqa: PLR0913
         agent_card: 'AgentCard',
         http_handler: 'RequestHandler',
         extended_agent_card: 'AgentCard | None' = None,
-        user_builder: 'UserBuilder | None' = None,
+       context_builder: 'ContextBuilder | None' = None,
         card_modifier: 'Callable[[AgentCard], Awaitable[AgentCard] | AgentCard] | None' = None,
         extended_card_modifier: 'Callable[[AgentCard, ServerCallContext], Awaitable[AgentCard] | AgentCard] | None' = None,
     ):
@@ -75,7 +75,7 @@ def __init__(  # noqa: PLR0913
         self.handler = REST03Handler(
             agent_card=agent_card, request_handler=http_handler
         )
-        self._user_builder = user_builder or default_user_builder
+        self._user_builder =context_builder or default_user_builder
 
     @rest_error_handler
     async def _handle_request(

src/a2a/server/request_handlers/grpc_handler.py

@@ -40,7 +40,7 @@
 
 logger = logging.getLogger(__name__)
 
-GrpcUserBuilder = Callable[[grpc.aio.ServicerContext], User]
+GrpcContextBuilder = Callable[[grpc.aio.ServicerContext], User]
 
 
 def default_grpc_user_builder(context: grpc.aio.ServicerContext) -> User:
@@ -64,10 +64,10 @@ def _get_metadata_value(
 
 
 def build_grpc_server_call_context(
-    context: grpc.aio.ServicerContext, user_builder: GrpcUserBuilder
+    context: grpc.aio.ServicerContext,context_builder: GrpcContextBuilder
 ) -> ServerCallContext:
     """Builds a ServerCallContext from a gRPC ServicerContext."""
-    user = user_builder(context)
+    user =context_builder(context)
     state = {'grpc_context': context}
     return ServerCallContext(
         user=user,
@@ -105,7 +105,7 @@ def __init__(
         self,
         agent_card: AgentCard,
         request_handler: RequestHandler,
-        user_builder: GrpcUserBuilder | None = None,
+       context_builder: GrpcContextBuilder | None = None,
         card_modifier: Callable[[AgentCard], Awaitable[AgentCard] | AgentCard]
         | None = None,
     ):
@@ -115,14 +115,14 @@ def __init__(
             agent_card: The AgentCard describing the agent's capabilities.
             request_handler: The underlying `RequestHandler` instance to
                              delegate requests to.
-            user_builder: Optional custom user builder to extract user from the
+           context_builder: Optional custom user builder to extract user from the
                           gRPC context.
             card_modifier: An optional callback to dynamically modify the public
               agent card before it is served.
         """
         self.agent_card = agent_card
         self.request_handler = request_handler
-        self.user_builder = user_builder or default_grpc_user_builder
+        self.user_builder =context_builder or default_grpc_user_builder
         self.card_modifier = card_modifier
 
     async def _handle_unary(

src/a2a/server/routes/__init__.py

@@ -1,13 +1,13 @@
 """A2A Routes."""
 
 from a2a.server.routes.agent_card_routes import create_agent_card_routes
-from a2a.server.routes.common import UserBuilder
+from a2a.server.routes.common import ContextBuilder
 from a2a.server.routes.jsonrpc_routes import create_jsonrpc_routes
 from a2a.server.routes.rest_routes import create_rest_routes
 
 
 __all__ = [
-    'UserBuilder',
+    'ContextBuilder',
     'create_agent_card_routes',
     'create_jsonrpc_routes',
     'create_rest_routes',

src/a2a/server/routes/common.py

@@ -1,3 +1,4 @@
+from abc import ABC, abstractmethod
 from collections.abc import Callable
 from typing import TYPE_CHECKING, Any
 
@@ -20,10 +21,6 @@
 )
 from a2a.server.context import ServerCallContext
 
-
-UserBuilder = Callable[[Request], User]
-
-
 class StarletteUser(User):
     """Adapts a Starlette BaseUser to the A2A User interface."""
 
@@ -41,36 +38,52 @@ def user_name(self) -> str:
         return self._user.display_name
 
 
-def default_user_builder(request: Request) -> User:
-    """Default strategy for creating an A2AUser from a Starlette Request."""
-    if 'user' in request.scope:
-        return StarletteUser(request.user)
-    return UnauthenticatedUser()
+class ContextBuilder(ABC):
+    """A class for building ServerCallContexts using the Starlette Request."""
+
+    @abstractmethod
+    def build(self, request: Request) -> ServerCallContext:
+        """Builds a ServerCallContext from a Starlette Request."""
+
+    @abstractmethod
+    def build_user(self, request: Request) -> User:
+        """Builds a User from a Starlette Request."""
+
+
+class DefaultContextBuilder(ContextBuilder):
+    """A default implementation of ContextBuilder."""
 
+    def build(self, request: Request) -> ServerCallContext:
+        """Builds a ServerCallContext from a Starlette Request.
 
-def build_server_call_context(
-    request: Request, user_builder: UserBuilder
-) -> ServerCallContext:
-    """Builds a ServerCallContext from a Starlette Request.
+        Args:
+            request: The incoming Starlette Request object.
 
-    Args:
-        request: The incoming Starlette Request object.
-        user_builder: A callable that creates a User from the request.
+        Returns:
+            A ServerCallContext instance populated with user and state
+            information from the request.
+        """
+        state = {}
+        if 'auth' in request.scope:
+            state['auth'] = request.auth
+        state['headers'] = dict(request.headers)
+        return ServerCallContext(
+            user=self.build_user(request),
+            state=state,
+            requested_extensions=get_requested_extensions(
+                request.headers.getlist(HTTP_EXTENSION_HEADER)
+            ),
+        )
 
-    Returns:
-        A ServerCallContext instance populated with user and state.
-    """
-    user = user_builder(request)
+    def build_user(self, request: Request) -> User:
+        """Builds a User from a Starlette Request.
 
-    state = {}
-    if 'auth' in request.scope:
-        state['auth'] = request.auth
-    state['headers'] = dict(request.headers)
+        Args:
+            request: The incoming Starlette Request object.
 
-    return ServerCallContext(
-        user=user,
-        state=state,
-        requested_extensions=get_requested_extensions(
-            request.headers.getlist(HTTP_EXTENSION_HEADER)
-        ),
-    )
+        Returns:
+            A User instance populated with user information from the request.
+        """
+        if 'user' in request.scope:
+            return StarletteUser(request.user)
+        return UnauthenticatedUser()

src/a2a/server/routes/jsonrpc_dispatcher.py

@@ -28,9 +28,8 @@
     build_error_response,
 )
 from a2a.server.routes.common import (
-    UserBuilder,
-    build_server_call_context,
-    default_user_builder,
+    ContextBuilder,
+
 )
 from a2a.types import A2ARequest
 from a2a.types.a2a_pb2 import (
@@ -145,7 +144,7 @@ def __init__(  # noqa: PLR0913
         agent_card: AgentCard,
         request_handler: RequestHandler,
         extended_agent_card: AgentCard | None = None,
-        user_builder: UserBuilder | None = None,
+       context_builder: ContextBuilder | None = None,
         card_modifier: Callable[[AgentCard], Awaitable[AgentCard] | AgentCard]
         | None = None,
         extended_card_modifier: Callable[
@@ -162,7 +161,7 @@ def __init__(  # noqa: PLR0913
               requests via http.
             extended_agent_card: An optional, distinct AgentCard to be served
               at the authenticated extended card endpoint.
-            user_builder: Optional custom user builder to extract user from the
+           context_builder: Optional custom user builder to extract user from the
               request.
             card_modifier: An optional callback to dynamically modify the public
               agent card before it is served.
@@ -183,7 +182,7 @@ def __init__(  # noqa: PLR0913
         self.extended_agent_card = extended_agent_card
         self.card_modifier = card_modifier
         self.extended_card_modifier = extended_card_modifier
-        self._user_builder = user_builder or default_user_builder
+        self._context_builder = context_builder or DefaultContextBuilder()
         self.enable_v0_3_compat = enable_v0_3_compat
         self._v03_adapter: JSONRPC03Adapter | None = None
 
@@ -192,7 +191,7 @@ def __init__(  # noqa: PLR0913
                 agent_card=agent_card,
                 http_handler=request_handler,
                 extended_agent_card=extended_agent_card,
-                user_builder=self._user_builder,
+               context_builder=self._context_builder,
                 card_modifier=card_modifier,
                 extended_card_modifier=extended_card_modifier,
             )

src/a2a/server/routes/jsonrpc_routes.py

@@ -19,7 +19,7 @@
 
 from a2a.server.context import ServerCallContext
 from a2a.server.request_handlers.request_handler import RequestHandler
-from a2a.server.routes.common import UserBuilder
+from a2a.server.routes.common import ContextBuilder
 from a2a.server.routes.jsonrpc_dispatcher import JsonRpcDispatcher
 from a2a.types.a2a_pb2 import AgentCard
 
@@ -29,7 +29,7 @@ def create_jsonrpc_routes(  # noqa: PLR0913
     request_handler: RequestHandler,
     rpc_url: str,
     extended_agent_card: AgentCard | None = None,
-    user_builder: UserBuilder | None = None,
+   context_builder: ContextBuilder | None = None,
     card_modifier: Callable[[AgentCard], Awaitable[AgentCard] | AgentCard]
     | None = None,
     extended_card_modifier: Callable[
@@ -51,7 +51,7 @@ def create_jsonrpc_routes(  # noqa: PLR0913
         rpc_url: The URL prefix for the RPC endpoints.
         extended_agent_card: An optional, distinct AgentCard to be served
           at the authenticated extended card endpoint.
-        user_builder: Optional custom user builder to extract user from the
+       context_builder: Optional custom context builder to extract user from the
           request.
         card_modifier: An optional callback to dynamically modify the public
           agent card before it is served.
@@ -71,7 +71,7 @@ def create_jsonrpc_routes(  # noqa: PLR0913
         agent_card=agent_card,
         request_handler=request_handler,
         extended_agent_card=extended_agent_card,
-        user_builder=user_builder,
+       context_builder=context_builder,
         card_modifier=card_modifier,
         extended_card_modifier=extended_card_modifier,
         enable_v0_3_compat=enable_v0_3_compat,

src/a2a/server/routes/rest_dispatcher.py

@@ -9,7 +9,7 @@
 from a2a.server.context import ServerCallContext
 from a2a.server.request_handlers.request_handler import RequestHandler
 from a2a.server.routes.common import (
-    UserBuilder,
+    ContextBuilder,
     build_server_call_context,
     default_user_builder,
 )
@@ -72,7 +72,7 @@ def __init__(  # noqa: PLR0913
         agent_card: AgentCard,
         request_handler: RequestHandler,
         extended_agent_card: AgentCard | None = None,
-        user_builder: UserBuilder | None = None,
+       context_builder: ContextBuilder | None = None,
         card_modifier: Callable[[AgentCard], Awaitable[AgentCard] | AgentCard]
         | None = None,
         extended_card_modifier: Callable[
@@ -87,7 +87,7 @@ def __init__(  # noqa: PLR0913
             request_handler: The underlying `RequestHandler` instance to delegate requests to.
             extended_agent_card: An optional, distinct AgentCard to be served
               at the authenticated extended card endpoint.
-            user_builder: Optional custom user builder to extract user from the
+           context_builder: Optional custom user builder to extract user from the
               request.
             card_modifier: An optional callback to dynamically modify the public
               agent card before it is served.
@@ -106,7 +106,7 @@ def __init__(  # noqa: PLR0913
         self.extended_agent_card = extended_agent_card
         self.card_modifier = card_modifier
         self.extended_card_modifier = extended_card_modifier
-        self._user_builder = user_builder or default_user_builder
+        self._user_builder =context_builder or default_user_builder
         self.request_handler = request_handler
 
     def _build_call_context(self, request: Request) -> ServerCallContext: