Backdoor Async

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Creates an unsafe way to call a function by providing defaults coeffects

namespace HH\Coeffects;

function backdoor_async<Tout>(
  (function(): Awaitable<Tout>) $fn,
): Awaitable<Tout>;

EXTREMELY UNSAFE. USE WITH CAUTION.

Parameters

• (function(): Awaitable<Tout>) $fn

Returns

• Awaitable<Tout>