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

# Idempotency

> Make retried GraphQL mutations safe to repeat

Some GraphQL mutations that perform side effects accept an `idempotencyKey` argument, so retrying the same request — for example after a network timeout — doesn't apply the operation twice.

```graphql theme={null}
mutation ReportEvent($input: ReportEventInput!) {
  reportEvent(input: $input) {
    eventId
  }
}
```

```json theme={null}
{
  "input": {
    "idempotencyKey": "unique-request-id-123",
    ...
  }
}
```

`reportEvent` is a confirmed example. Not every mutation accepts this argument — check the [schema reference](/api-and-sdks/api-reference/graphql/reference) for a given mutation's input type to see whether it exposes `idempotencyKey`.


## Related topics

- [Idempotency](/api-and-sdks/api-reference/rest/idempotency.md)
- [Metering architecture](/documentation/high-availability-and-scale/byoc/metering-architecture.md)
- [Introduction](/api-and-sdks/api-reference/webhooks/introduction.md)
- [Node.js SDK](/api-and-sdks/changelog/backend-graphql/node.md)
- [I want to run Stigg Sidecar and API in production](/guides/i-want-to/run-stigg-sidecar-api-in-production.md)