> ## Documentation Index
> Fetch the complete documentation index at: https://routeme.sh/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Replay checks

Replay checks verify that your node returns **correct** results. In simple terms: we compare your node’s response to what we observe from the network. If your node consistently disagrees with that baseline, it may be marked as having failed a replay check.

We run these checks on **read-only, deterministic** RPC methods. State-changing or non-deterministic methods (e.g. sends, subscriptions, filters) are not replayed, since their results are not comparable across nodes in the same way.

## **How they work (at a high level)**

* These checks run **asynchronously** and do not add latency to live consumer requests.
* Failures are counted per node (and per batch/time window in the portal). Repeated failures can lead to the node being temporarily taken out of production.
* Common causes: misconfigured nodes, sync issues, or bugs in how certain methods or parameters are handled.

## **What you can do**

Ensure your RPC endpoints return correct, deterministic results for the methods and chains you support. If you see replay check failures in [Inspect](/provider/inspect), investigate that node and fix configuration or sync issues.

See [When checks fail](/provider/quality-checks-recovery) for what happens after a failure and how to monitor recovery.