Cancel task request

Cancel Task Request (Client)

1. Description

This hook is called when the observed client agent sends task cancellation message through A2A protocol.
This hook must be used before the observed agent sends the A2A-compliant message to server agent.

2. Method

tasks/cancel

3. Reponse

The response is an AOSSuccessResponse object.

Decision	Behavior
`allow`	The observed agent should send the A2A-compliant cancellation message to the target agent.
`deny`	The A2A-compliant cancellation message should be blocked. Task should not be cancelled.

4. A2A payload

{
  "jsonrpc": "2.0",
  "id": 100,
  "method": "tasks/cancel",
  "params": {
    "id": "2232321",
    "metadata": {}
  }
}

5. AOS payload

{
 "jsonrpc": "2.0",
 "id": "2b10e2fd-f89c-4ff7-b972-5513cd2daeb4",
 "method" : "tasks/cancel",
 "params": {
     "payload": {
         "jsonrpc": "2.0",
         "id": 100,
         "method": "tasks/cancel",
         "params": {
         "id": "2232321",
         "metadata": {}
         }
     },
     "reasoning": "This task is taking too long when it should not.",
     "context": {
         "from": {
             "agent": {
                 "name": "Content generator",
                 "url": "https://cooking-assistant.openai.com/api/v1",
                 "instructions": "You are a helpful assistant that can answer questions and help with tasks.",
                 "version": "1.0.0",
                 "provider": {
                     "name": "OpenAI",
                     "url": "https://openai.com"
                 }
             },
             "role": "client"
         },
         "to": {
             "agent": {
                 "url": "https://api.story.com/v1",
                 "name": "Story teller",
                 "version": "1.0.0"
             },
             "role": "server"
         }
     }
 }
}

Cancel Task Request (Server)