> ## Documentation Index
> Fetch the complete documentation index at: https://wundergraphinc-brendan-add-external-directive.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Federation Compatibility Matrix

> The following list gives you an Overview of the compatibility between Cosmo and other Federation Implementations.

## Apollo Federation Version 1 Compatibility

| Directive             | State     |
| --------------------- | --------- |
| @extends              | Supported |
| @external             | Supported |
| @key                  | Supported |
| @key (composite keys) | Supported |
| @provides             | Supported |
| @requires             | Supported |
| @tag                  | Supported |

## Apollo Federation Version 2 Compatibility

### 2.0

| Directive                  | State                       |
| -------------------------- | --------------------------- |
| @inaccessible              | Supported                   |
| @override                  | Supported                   |
| @shareable                 | Supported                   |
| @key "resolvable" argument | Supported                   |
| @link                      | Supported (but unnecessary) |

### 2.1

| Directive                   | State     |
| --------------------------- | --------- |
| @composeDirective           | `Planned` |
| @requires "fields" argument | Supported |

### 2.3

| Directive         | State     |
| ----------------- | --------- |
| @key on INTERFACE | Supported |
| @interfaceObject  | Supported |

### 2.5

| Directive                                                | State     |
| -------------------------------------------------------- | --------- |
| [@authenticated](/federation/directives/authenticated)   | Supported |
| [@requiresScopes](/federation/directives/requiresscopes) | Supported |