3. Document container

The top-level value is a JSON object:

{
  "format": "open-loom",
  "version": "2.0",
  "exportedAt": "2026-07-08T21:14:00Z",
  "generator": { "name": "Aspen Grove", "version": "0.9.0" },
  "trees": [ /* one or more Tree objects, § 4 */ ],
  "agents": { /* optional shared agent registry, § 4.5 */ },
  "extensions": {}
}

Field	Type	Req	Notes
`format`	string	MUST	Literal `"open-loom"`. Primary detection signal.
`version`	string	MUST	`"<major>.<minor>"`. See § 3.1.
`exportedAt`	timestamp	SHOULD	See § 3.2.
`generator`	object	SHOULD	`name` + optional `version`, free-form.
`trees`	Tree[]	MUST	One or more. A single-tree export is a one-element array.
`agents`	map	MAY	Document-level agent registry shared across trees.
`extensions`	object	MAY	§ 7.

3.1 Versioning policy

Minor bumps add optional fields only. An importer for 2.0 MUST accept any 2.x document, ignoring fields it doesn't know.
Major bumps may change structure. Importers SHOULD refuse majors they don't understand, with a clear message.
Exporters MUST write the lowest version that expresses their content.

3.2 Timestamps, IDs, and text

Timestamps are ISO-8601 strings with timezone (UTC Z preferred), millisecond precision allowed: "2026-07-08T21:14:00.123Z".
IDs are opaque non-empty strings, unique within their scope (nodes and edges share a tree-wide scope; trees and agents are document-scoped). ULIDs are RECOMMENDED for new IDs. Importers MUST treat IDs as opaque — no format may be assumed — and MUST remap on collision with local data.
All text is UTF-8. Node text SHOULD be treated as Markdown-compatible plain text; importers MUST NOT require it to parse as Markdown.