---
title: ARCCHR0007 — Command handler must not append directly to the event log
editUrl: https://github.com/Cratis/Arc.TypeScript/edit/main/Documentation/code-analysis/ARCCHR0007.md
description: Return events from a Chronicle-backed command handler to preserve its append pipeline.
---


A decorated command's `handle()` should return events for the Chronicle integration to append.
Direct appends from `handle()` or `provide()` to `eventLog.append(...)` or `appendMany(...)`
(including `.transactional`) bypass the returned-event batch. The rule recognizes `this.store`,
a local store obtained with `await this.runtime.getStore(...)`, and stores obtained from a
`@inject(ChronicleReadModels)` or `@inject(ChronicleRuntime)` parameter, both through a local
variable and inline `await` calls. It does not follow helpers, callbacks, or arbitrary stores and
does not forbid standalone Arc commands from returning non-event responses.

```ts
// Instead of: await this.store.eventLog.append(this.id, new Registered());
return new Registered();
```

This is an analog of the .NET warning.
[Transactional commands](/arc/backend/typescript/chronicle/commands/transactional-commands/#what-is-outside-the-batch)
explains the batch boundary.