# PSR vs Edge Delivery

Two distinct layers. They are independent, and conflating them
misreads both.

## PSR — Preemptive Static Rendering

**Protocol feature.** Render HTML on mutation, not on request.

Mechanism: `@client` fires mutation → backend adapter triggers local
render runtime → HTML stored locally.

Works on a $5 VPS with local Bun. **No Edge required.** PSR is part
of the protocol; it's available to every Mizan deployment regardless
of hosting.

The strategy is manifest-driven rather than hand-wired per view. The
Edge manifest records each context's `render_strategy` — `"psr"` for
public contexts, `"dynamic_cached"` for user-scoped ones — emitted by
`mizan/export/` and the `export_edge_manifest` management command.
The render-on-mutation path reads that field to decide whether a
mutation triggers a local re-render or only a purge, and the SSR
bridge is what turns a component into HTML once it does. The Edge
layer consumes the same field for the same decision.

## Edge Delivery — Mizan Render (Paid Product)

Pre-rendered HTML cached globally on Cloudflare CDN.

Uses `fetch()` to a render Worker on a separate domain
(`render.mizan.cloud`) instead of `cache.put()`, because Workers
Cache API is per-datacenter only. `fetch()` across zones goes through
the global CDN cache path with Tiered Cache.

This layer is the paid Mizan Render product.

## Caching modes

- **Public content** — preemptive (render on mutation)
- **User-scoped content** — reactive only (purge on mutation, render
  on next request)

## Invariant

PSR logic does not couple to Cloudflare-specific APIs. PSR works
without any cloud infrastructure. Edge delivery extends PSR; it does
not replace it.