---
url: https://masyaka.github.io/injecute/errors/circular-dependency.md
description: Services depend on each other in a cycle
---

# `INJECUTE_CIRCULAR_DEPENDENCY`

**Services depend on each other in a cycle.**

## How to fix it

Break the cycle: extract the shared part into its own service, or resolve one side lazily with a function dependency (() => container.get(key)).

## Example

```ts
app
  .addSingleton('a', (b) => new A(b), ['b'])
  .addSingleton('b', (a) => new B(a), ['a']); // throws: a -> *b* -> a
```

## Breaking the cycle

* Move what both services need into a third service that neither depends on the other.
* Resolve one side lazily with a function dependency, so it is only resolved when used:

```ts
app.addSingleton('b', (getA) => new B(getA), [() => () => app.get('a')]);
```

## Handling it in code

```ts
import { InjecuteError } from 'injecute';

try {
  // ...
} catch (error) {
  if (error instanceof InjecuteError && error.code === 'INJECUTE_CIRCULAR_DEPENDENCY') {
    // error.message explains what happened; error.path is the resolution chain
  }
}
```

[All error codes](./index.md)