{
	"title": "Sequence",
	"required": ["participants", "messages"],
	"additionalProperties": false,
	"properties": {
		"participants": {
			"type": "array",
			"minItems": 2,
			"items": {
				"type": "object",
				"required": ["id", "label"],
				"additionalProperties": false,
				"properties": {
					"id": { "type": "string", "pattern": "^[A-Za-z_][A-Za-z0-9_.-]*$" },
					"label": { "type": "string", "maxLength": 32 },
					"sub": { "type": "string", "maxLength": 40 },
					"kind": {
						"enum": ["backend", "focal", "store", "external", "input", "security", "muted"]
					},
					"focal": { "type": "boolean" }
				}
			}
		},
		"messages": {
			"type": "array",
			"minItems": 1,
			"items": {
				"anyOf": [
					{
						"type": "array",
						"minItems": 2,
						"maxItems": 4,
						"items": [
							{ "type": "string" },
							{ "type": "string" },
							{ "type": "string" },
							{ "$ref": "#/$defs/msgKind" }
						]
					},
					{
						"type": "object",
						"required": ["from", "to"],
						"additionalProperties": false,
						"properties": {
							"from": { "type": "string" },
							"to": { "type": "string" },
							"label": { "type": "string", "maxLength": 44 },
							"kind": { "$ref": "#/$defs/msgKind" },
							"focal": { "type": "boolean" }
						}
					}
				]
			}
		},
		"fragments": {
			"type": "array",
			"items": {
				"type": "object",
				"required": ["kind", "from", "to"],
				"additionalProperties": false,
				"properties": {
					"kind": { "enum": ["alt", "opt", "loop", "par", "critical", "break"] },
					"label": { "type": "string", "maxLength": 40 },
					"from": { "type": "integer", "minimum": 0 },
					"to": { "type": "integer", "minimum": 0 },
					"else": { "type": "integer", "minimum": 0 },
					"elseLabel": { "type": "string", "maxLength": 40 }
				}
			}
		},
		"notes": {
			"type": "array",
			"items": {
				"type": "object",
				"required": ["at", "over", "text"],
				"additionalProperties": false,
				"properties": {
					"at": { "type": "integer", "minimum": 0 },
					"over": { "type": "array", "minItems": 1, "maxItems": 2, "items": { "type": "string" } },
					"text": { "type": "string", "maxLength": 80 }
				}
			}
		},
		"numbered": { "type": "boolean" }
	},
	"$defs": { "msgKind": { "enum": ["sync", "reply", "async", "self", "primary"] } }
}