{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://aaep-protocol.org/schemas/v1/core/agent.session.cancelled.schema.json",
  "title": "AAEP Event: agent.session.cancelled",
  "description": "Announces that the session was cancelled before completion. Cancellation may originate from the user, the producer itself, a timeout, or an external system. Defined normatively in Chapter 4 §4.1.4 of the AAEP specification.",

  "allOf": [
    { "$ref": "https://aaep-protocol.org/schemas/v1/envelope.schema.json" }
  ],

  "type": "object",
  "required": ["type", "cancelled_by", "summary_normal"],

  "properties": {
    "type": {
      "description": "MUST be the literal value 'aaep:agent.session.cancelled'.",
      "const": "aaep:agent.session.cancelled"
    },
    "cancelled_by": {
      "description": "Source of the cancellation. Determines how subscribers might frame the announcement to the user.",
      "type": "string",
      "enum": ["user", "producer", "timeout", "system"]
    },
    "summary_normal": {
      "description": "Human-readable description of why the cancellation occurred. Required.",
      "type": "string",
      "minLength": 1,
      "maxLength": 16384
    },
    "summary_terse": {
      "description": "Shorter form. Example: 'Cancelled.'",
      "type": "string",
      "minLength": 1,
      "maxLength": 4096
    },
    "summary_detailed": {
      "description": "Longer form with additional context about the cancellation.",
      "type": "string",
      "minLength": 1,
      "maxLength": 16384
    },
    "cancellation_reason": {
      "description": "Producer-specific reason code for the cancellation. Conventionally a short snake_case identifier.",
      "type": "string",
      "pattern": "^[a-z][a-z0-9_]{1,63}$",
      "examples": [
        "user_pressed_escape",
        "user_closed_window",
        "timeout_exceeded",
        "agent_determined_unnecessary",
        "external_signal_received",
        "policy_violation_detected"
      ]
    },
    "partial_result": {
      "description": "Brief description of any partial work produced before cancellation. Helps users decide whether to retry from scratch or resume.",
      "type": "string",
      "maxLength": 16384
    }
  },

  "examples": [
    {
      "@context": "https://aaep-protocol.org/context/v1",
      "type": "aaep:agent.session.cancelled",
      "event_id": "evt_6c2e8a1f4d7b3a9c",
      "session_id": "sess_2c91a7b4d23f1e88",
      "timestamp": "2026-05-24T14:22:18.450Z",
      "producer": {
        "agent_id": "retirement-planner",
        "agent_version": "1.4.2"
      },
      "urgency": "normal",
      "cancelled_by": "user",
      "summary_normal": "Cancelled at your request."
    },
    {
      "@context": "https://aaep-protocol.org/context/v1",
      "type": "aaep:agent.session.cancelled",
      "event_id": "evt_6c2e8a1f4d7b3a9c",
      "session_id": "sess_2c91a7b4d23f1e88",
      "timestamp": "2026-05-24T14:22:18.450Z",
      "producer": {
        "agent_id": "retirement-planner",
        "agent_version": "1.4.2"
      },
      "urgency": "normal",
      "cancelled_by": "user",
      "cancellation_reason": "user_pressed_escape",
      "summary_terse": "Cancelled.",
      "summary_normal": "Retirement plan generation cancelled at your request.",
      "partial_result": "Initial projection was drafted but no recommendations were generated."
    },
    {
      "@context": "https://aaep-protocol.org/context/v1",
      "type": "aaep:agent.session.cancelled",
      "event_id": "evt_6c2e8a1f4d7b3a9d",
      "session_id": "sess_2c91a7b4d23f1e89",
      "timestamp": "2026-05-24T14:35:42.100Z",
      "producer": {
        "agent_id": "support-agent",
        "agent_version": "3.0.1"
      },
      "urgency": "normal",
      "cancelled_by": "timeout",
      "cancellation_reason": "timeout_exceeded",
      "summary_normal": "Session timed out after 5 minutes of inactivity.",
      "summary_detailed": "Session was awaiting user confirmation for 300 seconds; default decision applied and session cancelled."
    }
  ]
}