{
  "$id": "https://schema.nfh.global/LineageEntry/v2.0",
  "x-iri": "https://schema.nfh.global/LineageEntry/v2.0",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "LineageEntry",
  "x-tags": [
    "common"
  ],
  "description": "A causal attribution record asserting that the Beckn transaction in which this entry appears was triggered by a specific upstream Beckn interaction. Used in Context.lineage at transaction boundaries — when a new transaction is initiated as a direct consequence of an upstream interaction. MUST NOT be included within subsequent steps of the same transaction, and MUST NOT be propagated by downstream responses.",
  "type": "object",
  "properties": {
    "action": {
      "description": "The Beckn endpoint of the upstream message that caused this transaction to be initiated.",
      "$ref": "https://schema.nfh.global/BecknEndpoint/v2.0/schema.json"
    },
    "transactionId": {
      "description": "The transactionId of the upstream Beckn transaction, taken from its Context.",
      "type": "string",
      "format": "uuid"
    },
    "messageId": {
      "description": "The messageId of the specific upstream message that directly triggered the creation of this transaction.",
      "type": "string",
      "format": "uuid"
    },
    "digest": {
      "description": "BLAKE2b-512 hash of the upstream message body bytes, encoded in Base64 and prefixed with the algorithm identifier. Format: BLAKE-512={base64EncodedHash}",
      "type": "string",
      "pattern": "^BLAKE-512=[A-Za-z0-9+/]+=*$",
      "example": "BLAKE-512=b6lf6lRgOweajukcvcLsagQ2T60+85kRh/Rd2bdS+TG/5ALebOEgDJfyCrre/1+BMu5nA94o4DT3pTFXuUg7sw=="
    }
  },
  "required": [
    "action",
    "transactionId",
    "messageId",
    "digest"
  ],
  "additionalProperties": false
}