{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://storyobjectmodel.com/schema/1.0/link-event.schema.json",
  "title": "SOM 1.0 som.link.* event payloads",
  "description": "Payloads for link.committed, link.gate_changed, link.withdrawn (v0.3.1 Proposal §3.1). The link is the Asset↔Destination connection (decision #3); usage[] is maintained from exactly these events under the §5 idempotent-upsert rules.",
  "type": "object",
  "required": ["message_type", "link_id", "asset_id", "destination_id", "compliance_gate_status"],
  "properties": {
    "message_type": { "type": "string", "enum": ["link.committed", "link.gate_changed", "link.withdrawn"] },
    "link_id": { "type": "string", "format": "uuid" },
    "asset_id": { "type": "string" },
    "destination_id": { "type": "string" },
    "committed_by": { "type": "string" },
    "committed_at": { "type": "string", "format": "date-time" },
    "compliance_gate_status": { "type": "string", "enum": ["PENDING", "CLEARED", "BLOCKED"] },
    "withdrawn": {
      "type": "object",
      "required": ["withdrawn_by", "withdrawn_at"],
      "properties": {
        "withdrawn_by": { "type": "string" },
        "withdrawn_at": { "type": "string", "format": "date-time" },
        "reason": { "type": "string" }
      },
      "additionalProperties": false
    },
    "extensions": { "type": "object", "patternProperties": { "^com\\.[a-z0-9-]+\\.": {} }, "additionalProperties": false }
  },
  "additionalProperties": false,
  "allOf": [
    {
      "if": { "properties": { "message_type": { "const": "link.committed" } } },
      "then": { "required": ["committed_by", "committed_at"] }
    },
    {
      "if": { "properties": { "message_type": { "const": "link.withdrawn" } } },
      "then": { "required": ["withdrawn"] },
      "else": { "not": { "required": ["withdrawn"] } }
    }
  ]
}