[API reference](https://evolu.dev/docs/api-reference) › [@evolu/sqlite-wasm](https://evolu.dev/docs/api-reference/sqlite-wasm) › OpfsName

```ts
const OpfsName: BrandType<
  Type<
    "String",
    string,
    string,
    TypeOfError<"String">,
    null,
    TypeOfError<"String">,
    never,
    string,
    true
  >,
  "OpfsName",
  OpfsNameError
>;
```

Defined in: [packages/sqlite-wasm/src/SahPool.ts:1238](https://github.com/evoluhq/evolu/blob/bc4578a260dd15d5bbf94b83765ca05984d194cb/packages/sqlite-wasm/src/SahPool.ts#L1238)

The name of a file or directory in OPFS, a [valid file
name](https://fs.spec.whatwg.org/#valid-file-name) of the File System
Standard on every platform in one spelling: not empty, not `.` or `..`,
without `/` or ``, which is a path separator on Windows, without NUL or a
lone surrogate, and in Unicode NFC.

Names that differ only in case are different names, but in WebKit on macOS,
whose file system ignores case by default, they name one directory, and two
pools can hold it at once, because WebKit locks a file by its path as
spelled. Spell each directory in one case.