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

# Production patterns

> Practical patterns for reliable RevoEngine low-code components.

## Validate early

Reject missing or invalid input before external calls. Keep endpoint validation and component checks aligned so background and direct executions behave consistently.

```js theme={null}
const orderId = api.input('orderId');
if (typeof orderId !== 'string' || orderId.length === 0) {
  api.throw(400, { code: 'INVALID_ORDER_ID' });
}
```

## Make retries explicit

RevoEngine does not blindly retry synchronous endpoint or SDK mutations. Use idempotency keys supported by the destination and record the correlation identifier with the execution result.

## Bound every read

Select only required database fields, use filters and `take`, and paginate. Use Storage streaming for large files and database export APIs for full datasets.

## Keep side effects observable

Log stable identifiers and decisions, not entire payloads. Return resource or execution IDs that an operator can use in Activity, Trace, or Job history.

## Separate reusable logic

* Libraries: shared in-process business rules.
* Components: reusable execution units with their own inputs and results.
* Endpoints: synchronous HTTP contracts.
* Job templates: durable background work.
* Events: decoupled typed routing.

## Handle uncertainty

If an HTTP request, upload, or custom runtime call is interrupted after dispatch, the outcome can be indeterminate. Check the destination or durable RevoEngine record before repeating the operation.

## Protect secrets

Resolve secrets at the latest possible moment, use them only in the target call, and redact error context. Never return a secret value from a component.