Pre-Solved Token Pool

The pattern

For the hottest domains, VexSolver runs dedicated background workers that continuously solve against the target and push the resulting tokens into a bounded channel buffer. When a customer request arrives, we pop a pre-solved token from the buffer in microseconds and return it immediately. You get the token in the time it takes to acknowledge the request over TCP.

How it flows

Fallback cascade

The pool workers use blocking sends on the buffer, so they only solve as fast as customers consume — there is no wasted proxy quota on tokens no one will use. If the pool empties under load, requests transparently fall through to:

1. Pool hit — ~50ms (hot path)
2. Replay — 2-4 seconds (template cached)
3. Cold capture — 5-8 seconds (new site)

You never see an error, only a slightly slower response.