# X_OVERLOADED

## Means

in-flight requests are at the configured ceiling

## Typical cause

more concurrent requests than `maxInflight` (1,000). Shed **before** any work — no route match, no auth, no body, no query — because the alternative is not "serve everyone" but "serve nobody": every request queues behind the same pool, p99 walks off the chart and client retries multiply the load. `@ultimat3/realtime`'s `AcceptBudget` is the same decision for sockets. Classified `retry-after`, and the response carries the header; also thrown by `@ultimat3/auth`'s KDF gate, which refuses a password hash when 8 are running and 64 are queued — each argon2id arena is ~19 MiB, so the caps bound memory the per-IP limiters cannot

## Fix

retry after the `Retry-After` header; to serve more at once call `configureHttp({ maxInflight: 2000 })` at module scope in a file under `apps/*/`, and add replicas to match. For the KDF half, `installKdfGate({ maxConcurrent, maxQueued })` from `@ultimat3/auth/adapter`, in `apps/web/runtime.ts`

[HTTP](/error-codes#http)