Module a2a 

A2A domain — the version negotiation model, the per-revision A2aFeatureProfile, and the value objects that the wire codecs (T28) lower into.

Where this fits in the protocol-neutral core

The protocol-neutral core in domain/jsonrpc and application/session already speaks JSON-RPC 2.0 — the same envelope A2A uses. T27 is a feature on top of that core: a per-revision codec (T08-style) and a per-revision A2aFeatureProfile (T05-style) that mirrors the MCP gating model. A future MCP↔A2A bridge (T28) is the consumer of both profiles; this module is what the bridge translates between.

The seam

A2aVersion is the only thing this module re-exports at the top level. The A2aFeatureProfile lives in a2a::feature and the per-revision wire types live under a2a::wire::v1_0. A codec for v1.0 implements the protocol-neutral application/jsonrpc::Codec trait so the dispatcher routes the same way it does for MCP.

Re-exports

pub use agent_card::AgentCapabilities;

pub use agent_card::AgentCard;

pub use agent_card::AgentCardBuilder;

pub use agent_card::AgentCardError;

pub use agent_card::AgentInterface;

pub use agent_card::AgentSkill;

pub use agent_card::GRPC;

pub use agent_card::HTTP_JSON;

pub use agent_card::JSONRPC;

pub use agent_card::ProtocolBinding;

pub use extended_agent_card::GetExtendedAgentCardRequest;

pub use extended_agent_card::GetExtendedAgentCardResponse;

pub use list_tasks::ListTasksRequest;

pub use list_tasks::ListTasksResponse;

pub use message::DataPart;

pub use message::FileContent;

pub use message::FilePart;

pub use message::Message;

pub use message::MessageRole;

pub use message::Part;

pub use message::TextPart;

pub use push_notification::PushNotificationAuthenticationInfo;

pub use push_notification::TaskPushNotificationConfig;

pub use push_notification_methods::CreateTaskPushNotificationConfigRequest;

pub use push_notification_methods::CreateTaskPushNotificationConfigResponse;

pub use push_notification_methods::DeleteTaskPushNotificationConfigRequest;

pub use push_notification_methods::DeleteTaskPushNotificationConfigResponse;

pub use push_notification_methods::GetTaskPushNotificationConfigRequest;

pub use push_notification_methods::GetTaskPushNotificationConfigResponse;

pub use push_notification_methods::ListTaskPushNotificationConfigsRequest;

pub use push_notification_methods::ListTaskPushNotificationConfigsResponse;

pub use send_message::MessageSendConfiguration;

pub use send_message::SendMessageRequest;

pub use send_message::SendMessageResponse;

pub use streaming_events::StreamingEvent;

pub use streaming_events::TaskArtifactUpdateEvent;

pub use streaming_events::TaskStatusUpdateEvent;

pub use task::Artifact;

pub use task::Task;

pub use task::TaskState;

pub use task::TaskStatus;

pub use task_lifecycle::CancelTaskRequest;

pub use task_lifecycle::CancelTaskResponse;

pub use task_lifecycle::GetTaskRequest;

pub use task_lifecycle::GetTaskResponse;

pub use version::A2aVersion;

pub use version::ParseA2aVersionError;

pub use well_known::AGENT_CARD_WELL_KNOWN_PATH;

pub use well_known::is_agent_card_well_known_path;

Modules

agent_card

The A2A AgentCard — the self-describing manifest an agent publishes at /.well-known/agent-card.json.

extended_agent_card

A2A GetExtendedAgentCard typed envelopes.

feature

A2aFeatureProfile — the per-revision capability bitset, derived from the same four inputs as the MCP profile.

list_tasks

A2A ListTasks typed envelopes.

message

A2A Message and Part value objects.

push_notification

A2A push-notification configuration value objects — the wire form.

push_notification_methods

A2A push-notification method envelopes — the four methods that read and write a task’s push-notification configurations.

send_message

A2A SendMessage typed envelopes — the request, the configuration, and the response.

streaming_events

A2A streaming event value objects — the TaskStatusUpdateEvent and TaskArtifactUpdateEvent types that flow over a Server-Sent Events connection.

task

A2A Task, TaskStatus, TaskState, and Artifact value objects.

task_lifecycle

A2A GetTask and CancelTask typed envelopes.

version

A2aVersion — the negotiated A2A revision, as a value object.

well_known

The A2A AgentCard well-known URI.