> For the complete documentation index, see [llms.txt](https://docs.rierino.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rierino.com/devops/api-event-and-process-flows/configuring-saga-steps/event-step/ml-and-ai-actions/service-a2a-requests.md).

# Service A2A Requests

## Service A2A Requests 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:

{% tabs %}
{% tab title="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                  | -       |
| {% endtab %}   |                                                                         |                         |         |

{% tab title="Fields (JSON Schema)" %}

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "eventMeta": {
      "type": "object",
      "properties": {
        "domain": {
          "type": "string",
          "description": "ID of the A2A server to interact with",
          "examples": ["procurement_specialist"],
          "default": null
        },
        "inputElement": {
          "type": "string",
          "description": "Json path for the input in request event payload in A2A JSON-RPC format",
          "examples": ["message"],
          "default": null
        },
        "outputElement": {
          "type": "string",
          "description": "Json path for the output in response event payload",
          "examples": ["output"],
          "default": null
        }
      }
    }
  }
}
```

{% endtab %}
{% endtabs %}

With event metadata parameters as:

{% tabs %}
{% tab title="Parameters (table)" %}

| Parameter     | Definition                                                   | Example | Default |
| ------------- | ------------------------------------------------------------ | ------- | ------- |
| Input Pattern | Jmespath expression for converting input payload to A2A call | -       | -       |
| {% endtab %}  |                                                              |         |         |

{% tab title="Parameters (JSON Schema)" %}

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "eventMeta": {
      "type": "object",
      "properties": {
        "parameters": {
          "type": "object",
          "properties": {
            "inputPattern": {
              "type": "string",
              "description": "Jmespath expression for converting input payload to A2A call",
              "default": null
            }
          }
        }
      }
    }
  }
}
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.rierino.com/devops/api-event-and-process-flows/configuring-saga-steps/event-step/ml-and-ai-actions/service-a2a-requests.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.