# Production latency

Makes the simulator respond as slowly as production Kalshi, using a per-endpoint latency profile measured against the live exchange.

A strategy that only works against a zero-latency book fails first under production latency, so the simulator can add the delay the live exchange adds. The profile, `netprof_kalshi_v1`, holds the latency and jitter measured against production Kalshi from us-east-2, the region it's served from. At the median, reads take 7 to 23 ms, and creating or canceling an order takes 12 to 13 ms against a quiet book. It's off by default.

```bash
export RYSTIC_URL=$(rystic run kalshi-twin -d --port 0 --name latency --scenario empty_book --json | jq -r .data.url)
curl -s "$RYSTIC_URL/_rystic/network" | jq -c '{enabled, profile: .profile.id}'
# -> {"enabled":false,"profile":"netprof_kalshi_v1"}
curl -s -X POST "$RYSTIC_URL/_rystic/network" -d '{"enabled":true}'
curl -s "$RYSTIC_URL/_rystic/network" | jq -c '{enabled, post_order_p50_ms: .profile.endpoints["POST /trade-api/v2/portfolio/events/orders"].out.quantiles_ms.p50}'
# -> {"enabled":true,"post_order_p50_ms":12.8}
curl -s -X POST "$RYSTIC_URL/_rystic/network" -d '{"enabled":false}'
```

The profile covers nine endpoints. `POST /_rystic/network` with `{"enabled":true}` turns it on, and `rystic run kalshi-twin --network on` (`RYSTIC_NETWORK=on`) boots with it on.

`GET /_rystic/network` reads the active per-endpoint profile, and `POST /_rystic/network` changes it. The same route sets injected rejects, which the [network profiles page](https://www.rystic.ai/docs/network-profiles.md) covers. The network-fault scenarios (`flaky_500`, `brownout_503`, `rate_limited` and the rest) carry such a profile.

A network-fault scenario replaces the active profile when it loads, or at the times its tape names. The next reset or scenario brings back the profile from before it. A profile you post survives resets, and so does whatever a post leaves in place while a scenario's profile is active. Latency and fault injection are on Pro and Enterprise.

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Source: https://www.rystic.ai/docs/simulators/kalshi/features/production-latency · Markdown: https://www.rystic.ai/docs/simulators/kalshi/features/production-latency.md