A2A Post

Communicate with an assistant using the Agent-to-Agent Protocol. Sends a JSON-RPC 2.0 message to the assistant.

• Request: Provide an object with jsonrpc, id, method, and optional params.
• Response: Returns a JSON-RPC response with task information or error.

Supported Methods:

• message/send: Send a message to the assistant
• tasks/get: Get the status and result of a task

Notes:

• Supports threaded conversations via thread context
• Messages can contain text and data parts
• Tasks run asynchronously and return completion status

POST /a2a/{assistant_id}

A2A Post

cURL

curl --request POST \
  --url https://api.example.com/a2a/{assistant_id} \
  --header 'Accept: <accept>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "id": "<string>",
  "params": {
    "message": {
      "parts": [
        {
          "kind": "text",
          "text": "<string>"
        }
      ],
      "messageId": "<string>"
    },
    "thread": {
      "threadId": "<string>"
    }
  }
}
'

import requests

url = "https://api.example.com/a2a/{assistant_id}"

payload = {
    "jsonrpc": "2.0",
    "id": "<string>",
    "params": {
        "message": {
            "parts": [
                {
                    "kind": "text",
                    "text": "<string>"
                }
            ],
            "messageId": "<string>"
        },
        "thread": { "threadId": "<string>" }
    }
}
headers = {
    "Accept": "<accept>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Accept: '<accept>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    id: '<string>',
    params: {
      message: {parts: [{kind: 'text', text: '<string>'}], messageId: '<string>'},
      thread: {threadId: '<string>'}
    }
  })
};

fetch('https://api.example.com/a2a/{assistant_id}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.example.com/a2a/{assistant_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'jsonrpc' => '2.0',
    'id' => '<string>',
    'params' => [
        'message' => [
                'parts' => [
                                [
                                                                'kind' => 'text',
                                                                'text' => '<string>'
                                ]
                ],
                'messageId' => '<string>'
        ],
        'thread' => [
                'threadId' => '<string>'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Accept: <accept>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.example.com/a2a/{assistant_id}"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": \"<string>\",\n  \"params\": {\n    \"message\": {\n      \"parts\": [\n        {\n          \"kind\": \"text\",\n          \"text\": \"<string>\"\n        }\n      ],\n      \"messageId\": \"<string>\"\n    },\n    \"thread\": {\n      \"threadId\": \"<string>\"\n    }\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Accept", "<accept>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.example.com/a2a/{assistant_id}")
  .header("Accept", "<accept>")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": \"<string>\",\n  \"params\": {\n    \"message\": {\n      \"parts\": [\n        {\n          \"kind\": \"text\",\n          \"text\": \"<string>\"\n        }\n      ],\n      \"messageId\": \"<string>\"\n    },\n    \"thread\": {\n      \"threadId\": \"<string>\"\n    }\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.com/a2a/{assistant_id}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Accept"] = '<accept>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"jsonrpc\": \"2.0\",\n  \"id\": \"<string>\",\n  \"params\": {\n    \"message\": {\n      \"parts\": [\n        {\n          \"kind\": \"text\",\n          \"text\": \"<string>\"\n        }\n      ],\n      \"messageId\": \"<string>\"\n    },\n    \"thread\": {\n      \"threadId\": \"<string>\"\n    }\n  }\n}"

response = http.request(request)
puts response.read_body

200

{
  "jsonrpc": "2.0",
  "id": "<string>",
  "result": {},
  "error": {
    "code": 123,
    "message": "<string>"
  }
}

Headers

Accept · enum<string> · required

Must be application/json

Available options: application/json

Path Parameters

assistant_id · string<uuid> · required

The ID of the assistant to communicate with

Body

application/json

jsonrpc · enum<string> · required

JSON-RPC version

Available options: 2.0

id · string · required

Request identifier

method · enum<string> · required

The method to invoke

Available options: message/send, tasks/get

params · Message Send Parameters · object

Method parameters

Message Send Parameters

Task Get Parameters

Show child attributes

Response

200

application/json

JSON-RPC response

jsonrpc · enum<string> · required

Available options: 2.0

id · string · required

result · object

Success result containing task information or task details

error · object

Error information if request failed

Show child attributes