# FxTypeId

Runtime symbol carried by every `Fx` implementation.

## Signatures

```ts
export declare const FxTypeId: unique symbol;
```

```ts
export type FxTypeId = typeof FxTypeId;
```

## Why

A global symbol lets independent packages recognize an `Fx` structurally without
invoking it or relying on a concrete implementation class.

## Ownership and lifetime

Reading or comparing the symbol starts no work and acquires no resources.

## Examples

```ts
import { FxTypeId, succeed } from "@typed/fx/Fx"

const carriesFxProtocol = FxTypeId in succeed("ready")
```