{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://aaep-protocol.org/schemas/v1/core/agent.session.started.schema.json",
  "title": "AAEP Event: agent.session.started",
  "description": "Announces the beginning of an agent session. This is the first event of every session and the anchor for the session's session_id. Defined normatively in Chapter 4 §4.1.1 of the AAEP specification.",

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

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

  "properties": {
    "type": {
      "description": "MUST be the literal value 'aaep:agent.session.started'.",
      "const": "aaep:agent.session.started"
    },
    "summary_normal": {
      "description": "Human-readable description of what the session will do at normal verbosity. Suitable for direct announcement to the user. Required on every agent.session.started event.",
      "type": "string",
      "minLength": 1,
      "maxLength": 16384
    },
    "summary_terse": {
      "description": "Shorter form of summary_normal for terse verbosity. Typically a few words.",
      "type": "string",
      "minLength": 1,
      "maxLength": 4096
    },
    "summary_detailed": {
      "description": "Longer form of summary_normal for detailed verbosity. Includes context, expected steps, and rationale where useful.",
      "type": "string",
      "minLength": 1,
      "maxLength": 16384
    },
    "expected_duration_ms": {
      "description": "Producer's estimate of total session duration in milliseconds. Subscribers MAY use this to set up progress UI or advise the user of expected wait time.",
      "type": "integer",
      "minimum": 0,
      "maximum": 86400000
    },
    "requested_by": {
      "description": "Identifier of the user, system, or process that initiated the session. Format is producer-defined; common patterns are 'user:<id>', 'system:<service>', or 'agent:<agent_id>'.",
      "type": "string",
      "minLength": 1,
      "maxLength": 256
    },
    "request_text": {
      "description": "The original natural-language request from the user, if available and not sensitive. Producers MUST NOT include secrets or excessive PII in this field.",
      "type": "string",
      "maxLength": 16384
    },
    "tools_available": {
      "description": "List of tool names the agent has access to in this session. Aids subscribers in setting expectations about possible actions.",
      "type": "array",
      "items": {
        "type": "string",
        "minLength": 1,
        "maxLength": 256
      },
      "maxItems": 256,
      "uniqueItems": true
    }
  },

  "examples": [
    {
      "@context": "https://aaep-protocol.org/context/v1",
      "type": "aaep:agent.session.started",
      "event_id": "evt_8a3f5b22c91e4d7a",
      "session_id": "sess_2c91a7b4d23f1e88",
      "timestamp": "2026-05-24T14:22:11.342Z",
      "producer": {
        "agent_id": "retirement-planner",
        "agent_version": "1.4.2"
      },
      "urgency": "normal",
      "summary_normal": "Retirement Planning Assistant is processing your request."
    },
    {
      "@context": "https://aaep-protocol.org/context/v1",
      "type": "aaep:agent.session.started",
      "event_id": "evt_8a3f5b22c91e4d7a",
      "session_id": "sess_2c91a7b4d23f1e88",
      "timestamp": "2026-05-24T14:22:11.342Z",
      "producer": {
        "agent_id": "retirement-planner",
        "agent_version": "1.4.2",
        "agent_name": "Retirement Planning Assistant",
        "model": "claude-opus-4-7"
      },
      "urgency": "normal",
      "verbosity": "normal",
      "localization_hints": {
        "primary_language": "en-US",
        "text_direction": "ltr",
        "available_languages": ["en-US", "yo-NG", "es-419"]
      },
      "summary_terse": "Started.",
      "summary_normal": "Retirement Planning Assistant is processing your request.",
      "summary_detailed": "Retirement Planning Assistant is processing your request to plan retirement savings strategy. Estimated 30 seconds. The assistant will read your financial profile, calculate projections, and draft a recommendation.",
      "expected_duration_ms": 30000,
      "requested_by": "user:folake",
      "request_text": "Plan my retirement savings strategy.",
      "tools_available": ["fetch_balance", "calculate_projection", "draft_plan"]
    }
  ]
}