{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://fablepool.org/schemas/fpcf/v1/envelope.schema.json",
  "title": "FablePool signed operation envelope, version 1",
  "type": "object",
  "required": ["v", "type", "id", "author", "seq", "prev", "ts", "body", "sig"],
  "additionalProperties": false,
  "properties": {
    "v": {
      "const": 1,
      "description": "Wire format major version."
    },
    "type": { "$ref": "defs.schema.json#/$defs/opType" },
    "id": { "$ref": "defs.schema.json#/$defs/opId" },
    "author": {
      "$ref": "defs.schema.json#/$defs/keyId",
      "description": "Signing key. One author key maintains one hash chain."
    },
    "seq": {
      "type": "integer",
      "minimum": 1,
      "maximum": 9007199254740991,
      "description": "Position in the author's chain; first operation is 1."
    },
    "prev": {
      "oneOf": [
        { "$ref": "defs.schema.json#/$defs/opId" },
        { "type": "null" }
      ],
      "description": "Id of the author's previous operation; null iff seq is 1."
    },
    "ts": { "$ref": "defs.schema.json#/$defs/timestamp" },
    "body": {
      "type": "object",
      "description": "Type-specific payload; validated against body.<type>.schema.json."
    },
    "sig": {
      "$ref": "defs.schema.json#/$defs/signature",
      "description": "Ed25519 over the canonical envelope minus sig and id."
    }
  }
}