Merge branch 'main' into make-fastapi-package-optional

Author: darkhaniop

CHANGELOG.md

@@ -1,5 +1,53 @@
 # Changelog
 
+## [0.3.0](https://github.com/a2aproject/a2a-python/compare/v0.2.16...v0.3.0) (2025-07-31)
+
+
+### ⚠ BREAKING CHANGES
+
+* **deps:** Make opentelemetry an optional dependency ([#369](https://github.com/a2aproject/a2a-python/issues/369))
+* **spec:** Update Agent Card Well-Known Path to `/.well-known/agent-card.json` ([#320](https://github.com/a2aproject/a2a-python/issues/320))
+* Remove custom `__getattr__` and `__setattr__` for `camelCase` fields in `types.py` ([#335](https://github.com/a2aproject/a2a-python/issues/335))
+* Add mTLS to SecuritySchemes, add oauth2 metadata url field, allow Skills to specify Security ([#362](https://github.com/a2aproject/a2a-python/issues/362))
+* Support for serving agent card at deprecated path ([#352](https://github.com/a2aproject/a2a-python/issues/352))
+
+### Features
+
+* Add `metadata` as parameter to `TaskUpdater.update_status()` ([#371](https://github.com/a2aproject/a2a-python/issues/371)) ([9444ed6](https://github.com/a2aproject/a2a-python/commit/9444ed629b925e285cd08aae3078ccd8b9bda6f2))
+* Add mTLS to SecuritySchemes, add oauth2 metadata url field, allow Skills to specify Security ([#362](https://github.com/a2aproject/a2a-python/issues/362)) ([be6c517](https://github.com/a2aproject/a2a-python/commit/be6c517e1f2db50a9217de91a9080810c36a7a1b))
+* Add RESTful API Serving ([#348](https://github.com/a2aproject/a2a-python/issues/348)) ([82a6b7c](https://github.com/a2aproject/a2a-python/commit/82a6b7cc9b83484a4ceabc2323e14e2ff0270f87))
+* Add server-side support for plumbing requested and activated extensions ([#333](https://github.com/a2aproject/a2a-python/issues/333)) ([4d5b92c](https://github.com/a2aproject/a2a-python/commit/4d5b92c61747edcabcfd825256a5339bb66c3e91))
+* Allow agent cards (default and extended) to be dynamic ([#365](https://github.com/a2aproject/a2a-python/issues/365)) ([ee92aab](https://github.com/a2aproject/a2a-python/commit/ee92aabe1f0babbba2fdbdefe21f2dbe7a899077))
+* Support for serving agent card at deprecated path ([#352](https://github.com/a2aproject/a2a-python/issues/352)) ([2444034](https://github.com/a2aproject/a2a-python/commit/2444034b7aa1d1af12bedecf40f27dafc4efec95))
+* support non-blocking `sendMessage` ([#349](https://github.com/a2aproject/a2a-python/issues/349)) ([70b4999](https://github.com/a2aproject/a2a-python/commit/70b499975f0811c8055ebd674bcb4070805506d4))
+* Type update to support fetching extended card ([#361](https://github.com/a2aproject/a2a-python/issues/361)) ([83304bb](https://github.com/a2aproject/a2a-python/commit/83304bb669403b51607973c1a965358d2e8f6ab0))
+
+
+### Bug Fixes
+
+* Add Input Validation for Task Context IDs in new_task Function ([#340](https://github.com/a2aproject/a2a-python/issues/340)) ([a7ed7ef](https://github.com/a2aproject/a2a-python/commit/a7ed7efed8fcdcc556616a5fc1cb8f968a116733))
+* **deps:** Reduce FastAPI library required version to `0.95.0` ([#372](https://github.com/a2aproject/a2a-python/issues/372)) ([a319334](https://github.com/a2aproject/a2a-python/commit/a31933456e08929f665ccec57ac07b8b9118990d))
+* Remove `DeprecationWarning` for regular properties ([#345](https://github.com/a2aproject/a2a-python/issues/345)) ([2806f3e](https://github.com/a2aproject/a2a-python/commit/2806f3eb7e1293924bb8637fd9c2cfe855858592))
+* **spec:** Add `SendMessageRequest.request` `json_name` mapping to `message` proto ([bc97cba](https://github.com/a2aproject/a2a-python/commit/bc97cba5945a49bea808feb2b1dc9eeb30007599))
+* **spec:** Add Transport enum to specification (https://github.com/a2aproject/A2A/pull/909) ([d9e463c](https://github.com/a2aproject/a2a-python/commit/d9e463cf1f8fbe486d37da3dd9009a19fe874ff0))
+
+
+### Documentation
+
+* Address typos in docstrings and docs. ([#370](https://github.com/a2aproject/a2a-python/issues/370)) ([ee48d68](https://github.com/a2aproject/a2a-python/commit/ee48d68d6c42a2a0c78f8a4666d1aded1a362e78))
+
+
+### Miscellaneous Chores
+
+* Add support for authenticated extended card method ([#356](https://github.com/a2aproject/a2a-python/issues/356)) ([b567e80](https://github.com/a2aproject/a2a-python/commit/b567e80735ae7e75f0bdb22f025b97895ce3b0dd))
+
+
+### Code Refactoring
+
+* **deps:** Make opentelemetry an optional dependency ([#369](https://github.com/a2aproject/a2a-python/issues/369)) ([9ad8b96](https://github.com/a2aproject/a2a-python/commit/9ad8b9623ffdc074ec561cbe65cfc2a2ba38bd0b))
+* Remove custom `__getattr__` and `__setattr__` for `camelCase` fields in `types.py` ([#335](https://github.com/a2aproject/a2a-python/issues/335)) ([cd94167](https://github.com/a2aproject/a2a-python/commit/cd941675d10868922adf14266901d035516a31cf))
+* **spec:** Update Agent Card Well-Known Path to `/.well-known/agent-card.json` ([#320](https://github.com/a2aproject/a2a-python/issues/320)) ([270ea9b](https://github.com/a2aproject/a2a-python/commit/270ea9b0822b689e50ed12f745a24a17e7917e73))
+
 ## [0.2.16](https://github.com/a2aproject/a2a-python/compare/v0.2.15...v0.2.16) (2025-07-21)
 
 

src/a2a/server/apps/jsonrpc/fastapi_app.py

@@ -109,13 +109,13 @@ def add_routes_to_app(
         )(self._handle_requests)
         app.get(agent_card_url)(self._handle_get_agent_card)
 
-        # add deprecated path only if the agent_card_url uses default well-known path
         if agent_card_url == AGENT_CARD_WELL_KNOWN_PATH:
-            app.get(PREV_AGENT_CARD_WELL_KNOWN_PATH, include_in_schema=False)(
-                self.handle_deprecated_agent_card_path
+            # For backward compatibility, serve the agent card at the deprecated path as well.
+            # TODO: remove in a future release
+            app.get(PREV_AGENT_CARD_WELL_KNOWN_PATH)(
+                self._handle_get_agent_card
             )
 
-        # TODO: deprecated endpoint to be removed in a future release
         if self.agent_card.supports_authenticated_extended_card:
             app.get(extended_agent_card_url)(
                 self._handle_get_authenticated_extended_agent_card

src/a2a/server/apps/jsonrpc/jsonrpc_app.py

@@ -4,7 +4,7 @@
 import traceback
 
 from abc import ABC, abstractmethod
-from collections.abc import AsyncGenerator
+from collections.abc import AsyncGenerator, Callable
 from typing import TYPE_CHECKING, Any
 
 from pydantic import ValidationError
@@ -151,12 +151,17 @@ class JSONRPCApplication(ABC):
     (SSE).
     """
 
-    def __init__(
+    def __init__(  # noqa: PLR0913
         self,
         agent_card: AgentCard,
         http_handler: RequestHandler,
         extended_agent_card: AgentCard | None = None,
         context_builder: CallContextBuilder | None = None,
+        card_modifier: Callable[[AgentCard], AgentCard] | None = None,
+        extended_card_modifier: Callable[
+            [AgentCard, ServerCallContext], AgentCard
+        ]
+        | None = None,
     ) -> None:
         """Initializes the JSONRPCApplication.
 
@@ -169,6 +174,11 @@ def __init__(
             context_builder: The CallContextBuilder used to construct the
               ServerCallContext passed to the http_handler. If None, no
               ServerCallContext is passed.
+            card_modifier: An optional callback to dynamically modify the public
+              agent card before it is served.
+            extended_card_modifier: An optional callback to dynamically modify
+              the extended agent card before it is served. It receives the
+              call context.
         """
         if not _package_starlette_installed:
             raise ImportError(
@@ -178,14 +188,18 @@ def __init__(
             )
         self.agent_card = agent_card
         self.extended_agent_card = extended_agent_card
+        self.card_modifier = card_modifier
+        self.extended_card_modifier = extended_card_modifier
         self.handler = JSONRPCHandler(
             agent_card=agent_card,
             request_handler=http_handler,
             extended_agent_card=extended_agent_card,
+            extended_card_modifier=extended_card_modifier,
         )
         if (
             self.agent_card.supports_authenticated_extended_card
             and self.extended_agent_card is None
+            and self.extended_card_modifier is None
         ):
             logger.error(
                 'AgentCard.supports_authenticated_extended_card is True, but no extended_agent_card was provided. The /agent/authenticatedExtendedCard endpoint will return 404.'
@@ -482,24 +496,23 @@ async def _handle_get_agent_card(self, request: Request) -> JSONResponse:
         Returns:
             A JSONResponse containing the agent card data.
         """
-        # The public agent card is a direct serialization of the agent_card
-        # provided at initialization.
+        if request.url.path == PREV_AGENT_CARD_WELL_KNOWN_PATH:
+            logger.warning(
+                f"Deprecated agent card endpoint '{PREV_AGENT_CARD_WELL_KNOWN_PATH}' accessed. "
+                f"Please use '{AGENT_CARD_WELL_KNOWN_PATH}' instead. This endpoint will be removed in a future version."
+            )
+
+        card_to_serve = self.agent_card
+        if self.card_modifier:
+            card_to_serve = self.card_modifier(card_to_serve)
+
         return JSONResponse(
-            self.agent_card.model_dump(
+            card_to_serve.model_dump(
                 exclude_none=True,
                 by_alias=True,
             )
         )
 
-    async def handle_deprecated_agent_card_path(
-        self, request: Request
-    ) -> JSONResponse:
-        """Handles GET requests for the deprecated agent card endpoint."""
-        logger.warning(
-            f"Deprecated agent card endpoint '{PREV_AGENT_CARD_WELL_KNOWN_PATH}' accessed. Please use '{AGENT_CARD_WELL_KNOWN_PATH}' instead. This endpoint will be removed in a future version."
-        )
-        return await self._handle_get_agent_card(request)
-
     async def _handle_get_authenticated_extended_agent_card(
         self, request: Request
     ) -> JSONResponse:
@@ -514,17 +527,24 @@ async def _handle_get_authenticated_extended_agent_card(
                 status_code=404,
             )
 
-        # If an explicit extended_agent_card is provided, serve that.
-        if self.extended_agent_card:
+        card_to_serve = self.extended_agent_card
+
+        if self.extended_card_modifier:
+            context = self._context_builder.build(request)
+            # If no base extended card is provided, pass the public card to the modifier
+            base_card = card_to_serve if card_to_serve else self.agent_card
+            card_to_serve = self.extended_card_modifier(base_card, context)
+
+        if card_to_serve:
             return JSONResponse(
-                self.extended_agent_card.model_dump(
+                card_to_serve.model_dump(
                     exclude_none=True,
                     by_alias=True,
                 )
             )
-        # If supports_authenticated_extended_card is true, but no specific
-        # extended_agent_card was provided during server initialization,
-        # return a 404
+        # If supports_authenticated_extended_card is true, but no
+        # extended_agent_card was provided, and no modifier produced a card,
+        # return a 404.
         return JSONResponse(
             {
                 'error': 'Authenticated extended agent card is supported but not configured on the server.'

src/a2a/server/apps/jsonrpc/starlette_app.py

@@ -22,11 +22,8 @@
         _package_starlette_installed = False
 
 from a2a.server.apps.jsonrpc.jsonrpc_app import (
-    CallContextBuilder,
     JSONRPCApplication,
 )
-from a2a.server.request_handlers.jsonrpc_handler import RequestHandler
-from a2a.types import AgentCard
 from a2a.utils.constants import (
     AGENT_CARD_WELL_KNOWN_PATH,
     DEFAULT_RPC_URL,
@@ -109,14 +106,15 @@ def routes(
             ),
         ]
 
-        # add deprecated path only if the agent_card_url uses default well-known path
         if agent_card_url == AGENT_CARD_WELL_KNOWN_PATH:
+            # For backward compatibility, serve the agent card at the deprecated path as well.
+            # TODO: remove in a future release
             app_routes.append(
                 Route(
                     PREV_AGENT_CARD_WELL_KNOWN_PATH,
-                    self.handle_deprecated_agent_card_path,
+                    self._handle_get_agent_card,
                     methods=['GET'],
-                    name='agent_card_path_deprecated',
+                    name='deprecated_agent_card',
                 )
             )
 

src/a2a/server/request_handlers/grpc_handler.py

@@ -18,6 +18,8 @@
         "'pip install a2a-sdk[grpc]'"
     ) from e
 
+from collections.abc import Callable
+
 import a2a.grpc.a2a_pb2_grpc as a2a_grpc
 
 from a2a import types
@@ -87,6 +89,7 @@ def __init__(
         agent_card: AgentCard,
         request_handler: RequestHandler,
         context_builder: CallContextBuilder | None = None,
+        card_modifier: Callable[[AgentCard], AgentCard] | None = None,
     ):
         """Initializes the GrpcHandler.
 
@@ -96,10 +99,13 @@ def __init__(
                              delegate requests to.
             context_builder: The CallContextBuilder object. If none the
                              DefaultCallContextBuilder is used.
+            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.context_builder = context_builder or DefaultCallContextBuilder()
+        self.card_modifier = card_modifier
 
     async def SendMessage(
         self,
@@ -331,7 +337,10 @@ async def GetAgentCard(
         context: grpc.aio.ServicerContext,
     ) -> a2a_pb2.AgentCard:
         """Get the agent card for the agent served."""
-        return proto_utils.ToProto.agent_card(self.agent_card)
+        card_to_serve = self.agent_card
+        if self.card_modifier:
+            card_to_serve = self.card_modifier(card_to_serve)
+        return proto_utils.ToProto.agent_card(card_to_serve)
 
     async def abort_context(
         self, error: ServerError, context: grpc.aio.ServicerContext

src/a2a/server/request_handlers/jsonrpc_handler.py

@@ -1,6 +1,6 @@
 import logging
 
-from collections.abc import AsyncIterable
+from collections.abc import AsyncIterable, Callable
 
 from a2a.server.context import ServerCallContext
 from a2a.server.request_handlers.request_handler import RequestHandler
@@ -62,17 +62,25 @@ def __init__(
         agent_card: AgentCard,
         request_handler: RequestHandler,
         extended_agent_card: AgentCard | None = None,
+        extended_card_modifier: Callable[
+            [AgentCard, ServerCallContext], AgentCard
+        ]
+        | None = None,
     ):
         """Initializes the JSONRPCHandler.
 
         Args:
             agent_card: The AgentCard describing the agent's capabilities.
             request_handler: The underlying `RequestHandler` instance to delegate requests to.
             extended_agent_card: An optional, distinct Extended AgentCard to be served
+            extended_card_modifier: An optional callback to dynamically modify
+              the extended agent card before it is served. It receives the
+              call context.
         """
         self.agent_card = agent_card
         self.request_handler = request_handler
         self.extended_agent_card = extended_agent_card
+        self.extended_card_modifier = extended_card_modifier
 
     async def on_message_send(
         self,
@@ -417,16 +425,27 @@ async def get_authenticated_extended_card(
         Returns:
             A `GetAuthenticatedExtendedCardResponse` object containing the config or a JSON-RPC error.
         """
-        if self.extended_agent_card is None:
+        if (
+            self.extended_agent_card is None
+            and self.extended_card_modifier is None
+        ):
             return GetAuthenticatedExtendedCardResponse(
                 root=JSONRPCErrorResponse(
                     id=request.id,
                     error=AuthenticatedExtendedCardNotConfiguredError(),
                 )
             )
 
+        base_card = self.extended_agent_card
+        if base_card is None:
+            base_card = self.agent_card
+
+        card_to_serve = base_card
+        if self.extended_card_modifier and context:
+            card_to_serve = self.extended_card_modifier(base_card, context)
+
         return GetAuthenticatedExtendedCardResponse(
             root=GetAuthenticatedExtendedCardSuccessResponse(
-                id=request.id, result=self.extended_agent_card
+                id=request.id, result=card_to_serve
             )
         )

src/a2a/server/tasks/task_updater.py

@@ -49,6 +49,7 @@ async def update_status(
         message: Message | None = None,
         final: bool = False,
         timestamp: str | None = None,
+        metadata: dict[str, Any] | None = None,
     ) -> None:
         """Updates the status of the task and publishes a `TaskStatusUpdateEvent`.
 
@@ -57,6 +58,7 @@ async def update_status(
             message: An optional message associated with the status update.
             final: If True, indicates this is the final status update for the task.
             timestamp: Optional ISO 8601 datetime string. Defaults to current time.
+            metadata: Optional metadata for extensions.
         """
         async with self._lock:
             if self._terminal_state_reached:
@@ -77,6 +79,7 @@ async def update_status(
                     task_id=self.task_id,
                     context_id=self.context_id,
                     final=final,
+                    metadata=metadata,
                     status=TaskStatus(
                         state=state,
                         message=message,