ADR-0004 · One client store per document drives every component

Status: Accepted, 2026-10-10.

Context

Three components each fetched the same document state and invented their own error handling, so a page could show three different stories at once.

Decision

getRedlineStore keeps one store per service, site and document on the page. It owns the state machine (static, probing, live, connect-required and the failure states), dedupes loads, starts at most one per five seconds unless forced, and bypasses the HTTP cache. Components subscribe and render; none fetches the state itself.

Why

One request and one answer per page; every component reports the same state with the same message from REDLINE_MESSAGES.

Consequences

Writes go through createRedlineClient and then force a store reload. The cache bypass exists because anonymous state is publicly cacheable (TD-005).

Evidence

c980877, 8cdd08a, 26164e9; test/client-store.test.js.

Revisit when

A component needs data the document state does not carry, or pages host several documents.