[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Type](https://evolu.dev/docs/api-reference/common/Type) › constantCaseToSnakeCase

```ts
function constantCaseToSnakeCase(
  value: string & Brand<"ConstantCaseIdentifier">,
): string & Brand<"SnakeCaseIdentifier">;
```

Defined in: [packages/common/src/Type.ts:6057](https://github.com/evoluhq/evolu/blob/dd96d79f1dbe9a49fa12ce8e0aa7d3d0177795ca/packages/common/src/Type.ts#L6057)

Converts a [ConstantCaseIdentifier](https://evolu.dev/docs/api-reference/common/Type/variables/ConstantCaseIdentifier) to a [SnakeCaseIdentifier](https://evolu.dev/docs/api-reference/common/Type/variables/SnakeCaseIdentifier).

Converts `HTTP2_PORT` to `http2_port`. Use [snakeCaseToConstantCase](https://evolu.dev/docs/api-reference/common/Type/functions/snakeCaseToConstantCase) to
recover the original spelling.