[Feat]: Support for the data part, type form

[Sorras]

Is your feature request related to a problem? Please describe.

The inspector does not support data parts of the form type.
The inspector was able to capture the response JSON, but I can't interecat with it in the UI. So I cannot test agents with this feature using the inspector.

Describe the solution you'd like

The inspector does not support data parts of the form type.
It would be nice to test agents with the data parts of the form type A2A feature.

Try using this agent that supports this feature:
https://github.com/a2aproject/a2a-samples/tree/main/samples/python/agents/adk_expense_reimbursement

The inspector was able to capture the response JSON, but I can't interecat with it in the UI. This my response to illustrate:

{
"contextId": "765fa301-94dc-4036-b1bb-2c673dbc19e3",
"final": true,
"kind": "status-update",
"status": {
"message": {
"contextId": "765fa301-94dc-4036-b1bb-2c673dbc19e3",
"kind": "message",
"messageId": "96e87427-8096-4bb2-a7e4-77a68f8b8ce4",
"parts": [
{
"data": {
"type": "form",
"form": {
"type": "object",
"properties": {
"date": {
"type": "string",
"format": "date",
"description": "Date of expense",
"title": "Date"
},
"amount": {
"type": "string",
"format": "number",
"description": "Amount of expense",
"title": "Amount"
},
"purpose": {
"type": "string",
"description": "Purpose of expense",
"title": "Purpose"
},
"request_id": {
"type": "string",
"description": "Request id",
"title": "Request ID"
}
},
"required": [
"purpose",
"request_id",
"date",
"amount"
]
},
"form_data": {
"purpose": "dinner with clients",
"request_id": "request_id_4836277",
"date": "December first",
"amount": "100 USD"
},
"instructions": null
},
"kind": "data"
}
],
"role": "agent",
"taskId": "2a1b39e5-0324-49a8-8e57-bab238e883eb"
},
"state": "input-required",
"timestamp": "2025-12-05T21:34:46.227881+00:00"
},
"taskId": "2a1b39e5-0324-49a8-8e57-bab238e883eb",
"id": "msg-1764970484298-q4zjs1xuq",
"validation_errors": []
}

Describe alternatives you've considered

No response

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[mescaja]

i guess this is also related with the Multi-turn conversation feature which by the looks of it is not currently supported by the A2A Inpector

I have been testing simple Multi_turn conversation scenarios like this one

1. Sent message "convert from eur to gbp" of kind "message" from A2A Inspector

{
  "transport": "JSONRPC",
  "method": "message/send",
  "message": {
    "contextId": "cc3b4efb-1b76-4829-803c-6a6b27c86506",
    "kind": "message",
    "messageId": "msg-1765019245065-6ogjxqwws",
    "metadata": {},
    "parts": [
      {
        "kind": "text",
        "text": "convert from eur to gbp"
      }
    ],
    "role": "user"
  }
}

2. got message back "Please confirm (Y/N)" of kind "status-update"

{
  "contextId": "cc3b4efb-1b76-4829-803c-6a6b27c86506",
  "final": true,
  "kind": "status-update",
  "status": {
    "message": {
      "contextId": "cc3b4efb-1b76-4829-803c-6a6b27c86506",
      "kind": "message",
      "messageId": "73e3ee57-aa62-44bd-9568-301f4adb367b",
      "parts": [
        {
          "kind": "text",
          "text": "Please confirm (Y/N)"
        }
      ],
      "role": "agent",
      "taskId": "86167dea-1a2a-4fe4-b153-3379568cbab2"
    },
    "state": "input-required",
    "timestamp": "2025-12-06T11:07:25.361808647Z"
  },
  "taskId": "86167dea-1a2a-4fe4-b153-3379568cbab2",
  "id": "msg-1765019245065-6ogjxqwws",
  "validation_errors": []
}

3. At this point, i have no ability to send a 2 parts message back to the Sever Agent like these

if i confirm Y

part0 = "convert from eur to gbp"
part1: "Y"

or in case i confirm N

part0 = "convert from eur to gbp"
part1: "N"

instead what happens is that a 1 part message goes out

part0: "Y"

or 

part0: "N"

The issue makes a multi-turn conversation unable to be tested from A2A Inspector. This would be a really nice feature to add in my view.

Not sure if there are any other tools out there supporting this feature.

[alDuncanson]

Hey @Sorras and @mescaja, I ran into the same issues as well so I started writing my own tool: Handler.

Hope this helps!