{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://adcontextprotocol.org/schemas/3.2.5/core/account-change.json",
  "title": "Account Change",
  "description": "Immutable metadata for one committed material change to account-scoped state recoverable through an authoritative AdCP read. The record is an ordered invalidation and audit aid, not a historical resource snapshot. Sellers MUST NOT include credentials, financial account numbers, raw audience members, raw logged events, webhook bodies, or unbounded before/after values.",
  "type": "object",
  "properties": {
    "change_id": {
      "type": "string",
      "description": "Stable seller-generated identifier for this logical change. Retries and notification re-emissions reuse this identifier.",
      "minLength": 1,
      "maxLength": 255,
      "pattern": "^[A-Za-z0-9_.:-]{1,255}$"
    },
    "recorded_at": {
      "type": "string",
      "format": "date-time",
      "description": "Time the seller committed or durably observed the change. Feed order is defined by the cursor, not by this timestamp."
    },
    "occurred_at": {
      "type": "string",
      "format": "date-time",
      "description": "Upstream business time when the change occurred, only when the seller can establish it reliably."
    },
    "batch_id": {
      "type": "string",
      "description": "Optional stable identifier grouping records produced by one committed operation or one external-source ingestion batch. Each independently repairable authoritative identity still receives its own record; batch_id does not change cursor ordering or notification identity.",
      "minLength": 1,
      "maxLength": 255,
      "pattern": "^[A-Za-z0-9_.:-]{1,255}$"
    },
    "resource": {
      "type": "object",
      "description": "Stable identity of the changed resource. Resource types are open for forward compatibility. account_id is always present; resource_id identifies the changed entity and parent_ids supplies any IDs needed to disambiguate nested resources.",
      "properties": {
        "type": {
          "type": "string",
          "description": "Open resource-type name such as account, media_buy, package, creative, creative_assignment, delivery_report, audience, event_source, catalog, or account_financials.",
          "minLength": 1,
          "maxLength": 100,
          "pattern": "^[a-z][a-z0-9_.-]{0,99}$"
        },
        "account_id": {
          "type": "string",
          "description": "Seller-assigned account containing the resource.",
          "minLength": 1,
          "maxLength": 255,
          "x-entity": "account"
        },
        "resource_id": {
          "type": "string",
          "description": "Canonical identifier for the resource within its type. For an account change this equals account_id.",
          "minLength": 1,
          "maxLength": 255
        },
        "parent_ids": {
          "type": "object",
          "description": "Additional canonical parent identifiers needed to repair a nested resource, for example media_buy_id and package_id for a creative assignment. Keys and values MUST NOT contain sensitive payload data.",
          "additionalProperties": {
            "type": "string",
            "maxLength": 255
          },
          "maxProperties": 12
        }
      },
      "required": [
        "type",
        "account_id",
        "resource_id"
      ],
      "additionalProperties": true
    },
    "action": {
      "type": "string",
      "description": "Material change action. Standard values are created, discovered, updated, status_changed, linked, unlinked, deleted, and purged. Future standard or vendor-namespaced values are allowed; receivers MUST treat unknown values as generic invalidations.",
      "minLength": 1,
      "maxLength": 100,
      "pattern": "^[a-z][a-z0-9_.-]{0,99}$"
    },
    "origin": {
      "type": "object",
      "description": "Server-derived origin classification. The seller MUST NOT trust caller-supplied origin or actor claims.",
      "properties": {
        "kind": {
          "type": "string",
          "enum": [
            "adcp",
            "seller_operator",
            "seller_system",
            "connected_platform",
            "unknown"
          ]
        },
        "connection_id": {
          "type": "string",
          "description": "Opaque, non-secret reference to the connected source when safe for this caller.",
          "maxLength": 255
        }
      },
      "required": [
        "kind"
      ],
      "additionalProperties": true
    },
    "resource_revision": {
      "type": [
        "integer",
        "string"
      ],
      "description": "Post-change revision exposed by the repair read, when that resource family defines one."
    },
    "changed_paths": {
      "type": "array",
      "description": "Bounded set of RFC 6901 JSON Pointers naming material fields that changed. Values are intentionally omitted.",
      "items": {
        "type": "string",
        "pattern": "^(|/.*)$",
        "maxLength": 500
      },
      "maxItems": 64,
      "uniqueItems": true
    },
    "repair": {
      "type": "object",
      "description": "Authoritative AdCP read the receiver uses to reconcile current state. The buyer constructs safe request arguments from the structured resource identity. A deleted or legally purged resource may instead declare unavailable with a categorical reason.",
      "properties": {
        "task": {
          "type": "string",
          "description": "Allowlisted authoritative read task. This is a repair hint, never an instruction to dispatch dynamically. The buyer constructs and validates the request locally from the authenticated feed account and resource identity.",
          "enum": [
            "list_accounts",
            "get_media_buys",
            "get_media_buy_delivery",
            "list_creatives",
            "sync_audiences",
            "sync_event_sources",
            "sync_catalogs",
            "get_account_financials",
            "list_products",
            "get_signals"
          ]
        },
        "available": {
          "type": "boolean",
          "default": true,
          "description": "False when deletion or compelled erasure makes the resource unavailable on the repair read."
        },
        "unavailable_reason": {
          "type": "string",
          "enum": [
            "deleted",
            "purged",
            "legal_erasure",
            "access_revoked",
            "other"
          ]
        }
      },
      "required": [
        "task"
      ],
      "additionalProperties": true
    },
    "actor": {
      "type": "object",
      "description": "Optional privacy-safe actor classification. Sellers MUST omit direct personal identifiers unless the authenticated caller is authorized for them.",
      "properties": {
        "type": {
          "type": "string",
          "enum": [
            "principal",
            "operator",
            "system",
            "platform",
            "unknown"
          ]
        },
        "id": {
          "type": "string",
          "description": "Opaque, redaction-safe actor reference.",
          "maxLength": 255
        }
      },
      "required": [
        "type"
      ],
      "additionalProperties": true
    },
    "reason": {
      "type": "string",
      "description": "Short machine-readable reason code, when available.",
      "maxLength": 100,
      "pattern": "^[a-z][a-z0-9_.-]{0,99}$"
    },
    "summary": {
      "type": "string",
      "description": "Optional brief, untrusted human-readable summary. MUST NOT contain secrets or sensitive payload data.",
      "maxLength": 500
    },
    "ext": {
      "allOf": [
        {
          "$ref": "https://adcontextprotocol.org/schemas/3.2.5/core/ext.json"
        }
      ],
      "maxProperties": 20,
      "description": "Bounded vendor extensions. The entire encoded change record, including extensions, MUST NOT exceed 64 KiB and remains subject to the same secret/PII prohibitions."
    }
  },
  "required": [
    "change_id",
    "recorded_at",
    "resource",
    "action",
    "origin",
    "repair"
  ],
  "additionalProperties": true,
  "examples": [
    {
      "description": "Creative modified on a connected platform",
      "data": {
        "change_id": "chg_01K38G7X8ZGX9T4F1Q5W6Y2M3N",
        "recorded_at": "2026-08-24T11:58:04Z",
        "occurred_at": "2026-08-24T11:57:41Z",
        "resource": {
          "type": "creative",
          "account_id": "acc_luma_shared",
          "resource_id": "cr_8421"
        },
        "action": "updated",
        "origin": {
          "kind": "connected_platform",
          "connection_id": "conn_social_primary"
        },
        "resource_revision": 12,
        "changed_paths": [
          "/name",
          "/assets/0"
        ],
        "repair": {
          "task": "list_creatives"
        }
      }
    }
  ]
}