fetch-ladder.md

How the fetch ladder works

When escalation is on and the client did not force renderJs / asp / proxyPool:

1. local — in-process fetch
2. sf_static — paid static
3. sf_js — + JS
4. sf_asp — + anti-bot
5. sf_residential — last resort

Classification stops escalation on usable content, terminal HTTP errors (including unhandled 4xx), or bot walls (401/403/429 → escalate further). Private/loopback hosts never reach paid providers.

Successful tiers are cached per domain (~24h, Redis or memory) so the next request can start mid-ladder.