[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [local‑first/Evolu](https://evolu.dev/docs/api-reference/common/local-first/Evolu) › AppNameError

Defined in: [packages/common/src/local-first/Evolu.ts:308](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/local-first/Evolu.ts#L308)

A plain structured error produced by a [Type](https://evolu.dev/docs/api-reference/common/Type/interfaces/Type) operation.

It is a domain value discriminated by `type`, not an instance of JavaScript's
global `TypeError`.

Each distinct error meaning and shape should use a unique `type`. Reuse a tag
only when it intentionally represents the same error contract. Accidental
reuse prevents reliable discriminated-union narrowing.

## Extends

- [`TypeError`](https://evolu.dev/docs/api-reference/common/Type/interfaces/TypeError)\<`"AppName"`\>

## Properties

<a id="type"></a>

### type

```ts
readonly type: "AppName";
```

Defined in: [packages/common/src/Type.ts:870](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/Type.ts#L870)

#### Inherited from

[`TypeError`](https://evolu.dev/docs/api-reference/common/Type/interfaces/TypeError).[`type`](https://evolu.dev/docs/api-reference/common/Type/interfaces/TypeError#type)

---

<a id="value"></a>

### value

```ts
readonly value: string & Brand<"UrlSafeString">;
```

Defined in: [packages/common/src/local-first/Evolu.ts:309](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/local-first/Evolu.ts#L309)