Service A2A Requests

This handler (com.rierino.handler.a2a.A2AServerEventHandler) provides ability to utilize existing microservice capabilities to be serviced over A2A to other AI agents

Handler Parameters

Parameter	Definition	Example	Default
server.state	Name of the state manager with MCP server configurations	mcp_server	genai_model
server.domain	Name of the server domain to include (for filtering server.state records)	procurement	-
saga.handler	Name of the saga event handler that executes tool sagas	ai_saga	saga

Servers

Servers used by this event handler are stored in a regular state manager with the following configuration parameters:

• Sagas: List of sagas that will be used for method specific calls (e.g. "get" saga for "tasks/get").

Actions

GetA2A

Responds with the agent card configuration, for ".well-known/agent.json" calls.

CallA2A

Responds to a request using A2A protocol. Event metadata fields applicable for this action are as follows:

Fields (table)

Field	Definition	Example	Default
Domain	ID of the A2A server to interact with	procurement_specialist	-
Input Element	Json path for the input in request event payload in A2A JSON-RPC format	message	-
Output Element	Json path for the output in response event payload	output	-

Fields (JSON Schema)

With event metadata parameters as:

Parameters (table)

Parameter	Definition	Example	Default
Input Pattern	Jmespath expression for converting input payload to A2A call	-	-

Parameters (JSON Schema)

For more information on A2A call specifications:

https://github.com/google/A2A/blob/main/specification/json/a2a.jsongithub.com

A2A Specification