v0.3 gRPC compat drops task status timestamp and three other fields

[ConnorMoss02]

What happens

Over the v0.3 gRPC compat endpoint, task statuses have no timestamp. The v0.3 JSON-RPC and REST compat endpoints include it.

Round trip through compat/v0_3/proto_utils.py:

timestamp after gRPC round trip: None      (sent 2026-03-15T10:30:00Z)
icon_url: None                              (sent http://x/icon.png)
skill security: None                        (sent [{'oauth': ['read']}])

OAuth2SecurityScheme.oauth2_metadata_url is dropped the same way.

Why

proto_utils.py doesn't map these four fields in either direction. conversions.py, used by the JSON-RPC and REST compat paths, maps all four.

Version

main @ f3ac824

[rohityan]

Hi @ConnorMoss02, thanks for reporting this. I was able to reproduce the behavior in my test environment.

In src/a2a/compat/v0_3/proto_utils.py, the serialization (ToProto) and deserialization (FromProto) routines omit four fields when converting between v0.3 Pydantic models (a2a.compat.v0_3.types) and Protocol Buffer definitions (a2a_pb2):

• ToProto.task_status and FromProto.task_status omit mapping timestamp using protobuf FromJsonString and ToJsonString.
• ToProto.agent_card and FromProto.agent_card omit mapping icon_url.
• ToProto.skill and FromProto.skill omit delegating skill security schemes to ToProto.security and FromProto.security.
• ToProto.security_scheme and FromProto.security_scheme omit forwarding oauth2_metadata_url on OAuth2 security schemes.

Unlike src/a2a/compat/v0_3/conversions.py (used by REST and JSON-RPC), proto_utils.py does not synchronize these fields, leading to data loss across gRPC round trips.

Your #1277 appears to fix this issue. Till your PR gets reviewed as a workaround you can work around this at the application level

• Wrap ToProto.task_status, FromProto.task_status, ToProto.agent_card, and FromProto.agent_card to manually handle fields that are not automatically converted.
  • In your task_status wrapper, parse the ISO 8601 string into proto_status.timestamp via FromJsonString() on serialization, and read it back via ToJsonString() on deserialization.
  • In your agent_card wrapper, copy icon_url, append converted skill security schemes, and set oauth2_metadata_url on any configured OAuth2 schemes.