A2A Protocol

Agent-to-Agent protocol — open standard for inter-agent communication, discovery, and task delegation.

AgentOven natively implements the Agent-to-Agent (A2A) protocol — an open standard by Google (now Linux Foundation) for inter-agent communication. Every agent registered with AgentOven automatically gets an A2A endpoint.

Agent Card

Every baked agent publishes an Agent Card at /.well-known/agent.json describing its capabilities, skills, and supported content types. This enables automatic discovery by other agents and clients.

json

{
  "name": "research-bot",
  "description": "Research and summarization agent",
  "url": "https://oven.example.com/agents/research-bot/a2a",
  "version": "1.0.0",
  "capabilities": {
    "streaming": true,
    "pushNotifications": true
  },
  "skills": [
    {
      "id": "web-search",
      "name": "Web Search",
      "description": "Search the web for information"
    },
    {
      "id": "summarization",
      "name": "Summarization",
      "description": "Summarize long documents"
    }
  ]
}

Task Lifecycle

Tasks flow through a well-defined state machine: submitted → working → completed (or failed / canceled). Clients can poll for status or subscribe via SSE streaming.

State	Description
`submitted`	Task received and queued
`working`	Agent is actively processing the task
`completed`	Task finished with artifacts
`failed`	Task encountered an unrecoverable error
`canceled`	Task was canceled by the client

Sending a Task

Tasks are sent as JSON-RPC 2.0 messages to the agent's A2A endpoint:

terminal

$ curl -X POST https://oven.example.com/agents/research-bot/a2a \
    -H "Content-Type: application/json" \
    -d '{
      "jsonrpc": "2.0",
      "method": "tasks/send",
      "id": "1",
      "params": {
        "id": "task-001",
        "message": {
          "role": "user",
          "parts": [{"type":"text","text":"Summarize AI safety papers"}]
        }
      }
    }'

Streaming (SSE)

Use tasks/sendSubscribe to get real-time streaming responses via Server-Sent Events. The SDK handles reconnection and artifact assembly automatically.

terminal

$ curl -N -X POST https://oven.example.com/agents/research-bot/a2a \
    -H "Content-Type: application/json" \
    -H "Accept: text/event-stream" \
    -d '{
      "jsonrpc": "2.0",
      "method": "tasks/sendSubscribe",
      "id": "2",
      "params": {
        "id": "task-002",
        "message": {
          "role": "user",
          "parts": [{"type":"text","text":"Stream analysis of AI safety"}]
        }
      }
    }'

Multi-Agent Communication

A2A enables agents to discover and communicate with each other. An agent can query the Menu for available agents, read their Agent Cards, and delegate tasks — all through standard A2A protocol.

python

from agentoven import AgentOven

oven = AgentOven("http://localhost:8080")

# Agent discovers another agent via the Menu
menu = oven.menu.list()
writer = next(a for a in menu if "writing" in a.skills)

# Delegate a sub-task via A2A
result = oven.a2a.send_task(
    agent=writer.name,
    message="Write a blog post about these findings: ...",
)
print(result.text)

Push Notifications

For long-running tasks, agents can send push notifications to a webhook URL. Configure the callback in the task params:

json

{
  "jsonrpc": "2.0",
  "method": "tasks/send",
  "id": "3",
  "params": {
    "id": "task-003",
    "message": {
      "role": "user",
      "parts": [{"type":"text","text":"Long analysis job"}]
    },
    "pushNotification": {
      "url": "https://my-app.com/webhooks/agentoven",
      "events": ["completed", "failed"]
    }
  }
}