Architecture — the conformance ladder
The protocol is a ladder, not a gate. Every level is a respected membership class; each level up unlocks more of the network’s value. Levels are cumulative.
§1.1 The levels
| Level | Name | Requirements (summary) | Badge | Typical effort |
|---|---|---|---|---|
| L0 | Listed | Appears in the registry with a reviewed entry: canonical URL, declared aliases, entity domains, crawl/reuse policy. | listed |
One PR, minutes |
| L1 | Linked | Publishes the manifest (§2) with identity, conformance target, public_url pattern, license, permitted_use, org-level contact. Links out to peers. |
linked |
≤ 1 hour (a static JSON file) |
| L2 | Publishes | Serves ≥ 1 conforming place feed (§3) passing the validator at profile Core. |
publishes |
One afternoon (small apps); days (medium) |
| L3 | Serves & consumes | Serves the read API (§4.1) or live-refreshed feeds with sync signals (§4.4); consumes ≥ 1 peer feed under the consumption rules (§4.3). | interop |
Days |
| L4 | Federates | Accepts writes (§4.2) with source+external_id idempotency; optionally exposes MCP (§4.5). |
federates |
Per-app |
| — | Directory-only | For apps whose records are irreducibly personal, or who choose not to publish: L0/L1 forever, stated plainly, respected. | listed / linked |
— |
| — | Link-out-only | People-domain apps: L0/L1 ceiling by rule §7.1, not by choice. | listed |
— |
§1.2 Preconditions for L2+
From observed production failures (the “discovery trap”):
- A real
robots.txt(HTTP 200,text/plain). - The manifest path excluded from SPA catch-alls. The validator treats
200 + text/htmlat a discovery path as absent (the soft-404 rule), with byte-size equality against/as the discriminator.
§1.3 The HXL/CSV on-ramp (below L2)
An HXL-tagged spreadsheet at a stable URL is an accepted generator input:
conversion tooling (the skill / the validator’s convert mode) produces the
conforming JSON feed from it. One canonical schema still holds (§3.2);
conformance is measured on the produced feed. The converter MUST drop
contact columns (§7.2) unless declared institutional.
§1.4 Design constraint: the afternoon bar
The floor for “publishes data” is deliberately one afternoon of work with exactly one human decision (the PII gate). Normative changes that would raise that bar require an RFC that names the cost explicitly (see Appendix A for the walkthrough this bar is calibrated against).