---
description: fetching data from relays
alwaysApply: false
---

# Fetching Data with Controllers

We fetch data from relays using controllers:

- Start controllers immediatly; don't await.
- Stream via onEvent; dedupe replaceables; emit immediately.
- Parallel local/remote queries; complete on EOSE.
- Finalize and persist since after completion.
- Guard with generations to cancel stale runs.
- UI flips off loading on first streamed result.

We always include and prefer local relays for reads; optionally rebroadcast fetched content to local relays (depending on setting); and tolerate local‑only mode for writes (queueing for later).

Since we are streaming results, we should NEVER use timeouts for fetching data. We should always rely on EOSE.

In short: Local-first hydration, background network fetch, reactive updates, and replaceable lookups provide instant UI with eventual consistency. Use local relays as local data store for everything we fetch from remote relays.