# FxInput

An Fx accepted at a DOM host boundary while preserving error and service inference.

## Signatures

```ts
export type FxInput<A = any> = Fx<A, any, any> | Fx<A, never, never> | Fx<never, any, any> | Fx<never, never, any>;
```

## Why

The explicit union retains precise `never` channels during conditional and
mapped-type inference used by custom hosts.

## Ownership and lifetime

Supplying an Fx starts no work. Its rendering Scope owns subscription and interruption.