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A2A Sample Methods and JSON Responses
Agent Card
json
{
"name": "Google Maps Agent",
"description": "Plan routes, remember places, and generate directions",
"url": "https://maps-agent.google.com",
"provider": {
"organization": "Google",
"url": "https://google.com"
},
"version": "1.0.0",
"authentication": {
"schemes": "OAuth2"
},
"defaultInputModes": ["text/plain"],
"defaultOutputModes": ["text/plain", "application/html"],
"capabilities": {
"streaming": true,
"pushNotifications": false
},
"skills": [
{
"id": "route-planner",
"name": "Route planning",
"description": "Helps plan routing between two locations",
"tags": ["maps", "routing", "navigation"],
"examples": [
"plan my route from Sunnyvale to Mountain View",
"what's the commute time from Sunnyvale to San Francisco at 9AM",
"create turn by turn directions from Sunnyvale to Mountain View"
],
"outputModes": ["application/html", "video/mp4"]
},
{
"id": "custom-map",
"name": "My Map",
"description": "Manage a custom map with your own saved places",
"tags": ["custom-map", "saved-places"],
"examples": [
"show me my favorite restaurants on the map",
"create a visual of all places I've visited in the past year"
],
"outputModes": ["application/html"]
}
]
}Send a Task
Allows a client to send content to a remote agent to start a new Task, resume an interrupted Task, or reopen a completed Task. A Task interrupt may be caused due to an agent requiring additional user input or a runtime error.
Request
json
{
"jsonrpc": "2.0",
"id": 1,
"method": "tasks/send",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "tell me a joke"
}
]
},
"metadata": {}
}
}Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "completed"
},
"artifacts": [
{
"name": "joke",
"parts": [
{
"type": "text",
"text": "Why did the chicken cross the road? To get to the other side!"
}
]
}
],
"metadata": {}
}
}Get a Task
Clients may use this method to retrieve the generated artifacts for a Task. The agent determines the retention window for Tasks previously submitted to it.
Request
json
{
"jsonrpc": "2.0",
"id": 1,
"method": "tasks/get",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"historyLength": 10,
"metadata": {}
}
}Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "completed"
},
"artifacts": [
{
"parts": [
{
"type": "text",
"text": "Why did the chicken cross the road? To get to the other side!"
}
]
}
],
"history": [
{
"role": "user",
"parts": [
{
"type": "text",
"text": "tell me a joke"
}
]
}
],
"metadata": {}
}
}Cancel a Task
A client may choose to cancel previously submitted Tasks.
Request
json
{
"jsonrpc": "2.0",
"id": 1,
"method": "tasks/cancel",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"metadata": {}
}
}Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": 1,
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "canceled"
},
"metadata": {}
}
}Set Task Push Notifications
Clients may configure a push notification URL for receiving an update on Task status change.
Request
json
{
"jsonrpc": "2.0",
"id": 1,
"method": "tasks/pushNotification/set",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"pushNotificationConfig": {
"url": "https://example.com/callback",
"authentication": {
"schemes": ["jwt"]
}
}
}
}Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"pushNotificationConfig": {
"url": "https://example.com/callback",
"authentication": {
"schemes": ["jwt"]
}
}
}
}Get Task Push Notifications
Clients may retrieve the currently configured push notification configuration for a Task using this method.
Request
json
{
"jsonrpc": "2.0",
"id": 1,
"method": "tasks/pushNotification/get",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64"
}
}Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"pushNotificationConfig": {
"url": "https://example.com/callback",
"authentication": {
"schemes": ["jwt"]
}
}
}
}Multi-turn Conversations
A Task may pause to be executed on the remote agent if it requires additional user input.
Request - seq 1
json
{
"jsonrpc": "2.0",
"id": 1,
"method": "tasks/send",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "request a new phone for me"
}
]
},
"metadata": {}
}
}Response - seq 2
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "input-required",
"message": {
"parts": [
{
"type": "text",
"text": "Select a phone type (iPhone/Android)"
}
]
}
},
"metadata": {}
}
}Request - seq 3
json
{
"jsonrpc": "2.0",
"id": 2,
"method": "tasks/send",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "Android"
}
]
},
"metadata": {}
}
}Response - seq 4
json
{
"jsonrpc": "2.0",
"id": 2,
"result": {
"id": 1,
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "completed"
},
"artifacts": [
{
"name": "order-confirmation",
"parts": [
{
"type": "text",
"text": "I have ordered a new Android device for you. Your request number is R12443"
}
],
"metadata": {}
}
],
"metadata": {}
}
}Streaming Support
For clients and remote agents capable of communicating over HTTP with SSE, clients can send the RPC request with method tasks/sendSubscribe when creating a new Task.
Request
json
{
"method": "tasks/sendSubscribe",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "write a long paper describing the attached pictures"
},
{
"type": "file",
"file": {
"mimeType": "image/png",
"data": "<base64-encoded-content>"
}
}
]
},
"metadata": {}
}
}Example Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": 1,
"status": {
"state": "working",
"timestamp": "2025-04-02T16:59:25.331844"
},
"final": false
}
}Resubscribe to Task
A disconnected client may resubscribe to a remote agent that supports streaming to receive Task updates via SSE.
Request
json
{
"method": "tasks/resubscribe",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"metadata": {}
}
}Example Response
json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"artifact": [
{
"parts": [
{
"type": "text",
"text": "<section 2...>"
}
],
"index": 0,
"append": true,
"lastChunk": false
}
]
}
}Non-textual Media
Following is an example interaction between a client and an agent with non-textual data.
Request - seq 1
json
{
"jsonrpc": "2.0",
"id": 9,
"method": "tasks/send",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "Analyze the attached report and generate high level overview"
},
{
"type": "file",
"file": {
"mimeType": "application/pdf",
"data": "<base64-encoded-content>"
}
}
]
},
"metadata": {}
}
}Response - seq 2
json
{
"jsonrpc": "2.0",
"id": 9,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "working",
"message": {
"role": "agent",
"parts": [
{
"type": "text",
"text": "analysis in progress, please wait"
}
],
"metadata": {}
}
},
"metadata": {}
}
}Request - seq 3
json
{
"jsonrpc": "2.0",
"id": 10,
"method": "tasks/get",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"metadata": {}
}
}Response - seq 4
json
{
"jsonrpc": "2.0",
"id": 9,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "completed"
},
"artifacts": [
{
"parts": [
{
"type": "text",
"text": "<generated analysis content>"
}
],
"metadata": {}
}
],
"metadata": {}
}
}Structured Output
Both the client or the agent can request structured output from the other party.
Request
json
{
"jsonrpc": "2.0",
"id": 9,
"method": "tasks/send",
"params": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "Show me a list of my open IT tickets",
"metadata": {
"mimeType": "application/json",
"schema": {
"type": "array",
"items": {
"type": "object",
"properties": {
"ticketNumber": { "type": "string" },
"description": { "type": "string" }
}
}
}
}
}
]
},
"metadata": {}
}
}Response
json
{
"jsonrpc": "2.0",
"id": 9,
"result": {
"id": "de38c76d-d54c-436c-8b9f-4c2703648d64",
"sessionId": "c295ea44-7543-4f78-b524-7a38915ad6e4",
"status": {
"state": "working",
"message": {
"role": "agent",
"parts": [
{
"type": "text",
"text": "[{\"ticketNumber\":\"REQ12312\",\"description\":\"request for VPN access\"},{\"ticketNumber\":\"REQ23422\",\"description\":\"Add to DL - team-gcp-onboarding\"}]"
}
],
"metadata": {}
}
},
"metadata": {}
}
}Related Articles
- A2A Protocol Development Guide(TypeScript)
- Python A2A: A Comprehensive Guide to Google's Agent-to-Agent Protocol
- Understanding A2A Protocol: A Comprehensive Guide
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