The any-system guide explains how to prepare each route; the A2A guide documents the current public agent separately. The preview clients do not install a connector, schedule a sync, or activate a supplier. An agent skill does not give its user account or commercial authority.
Check before calling
The live application contract is athttps://middlemantechnologies.com/openapi.json. The supplier preview OpenAPI file describes the implementation being prepared for release.
If the live contract lacks a supplier route, wait for the application release. Do not treat a 404, login page or framework response as a successful integration. When available, /api/v1/supplier/me reports the capabilities your key can use. This preview reports validate: true, with ingest, publish, quote, reserve and order all false.
The existing public read API is separate and does not require a supplier key.