> ## Documentation Index
> Fetch the complete documentation index at: https://cosmo-docs.wundergraph.com/llms.txt
> Use this file to discover all available pages before exploring further.

# @deprecated

> The @deprecated directive marks fields, arguments, input fields, and enum values as deprecated in the schema.

## Definition

```graphql theme={"system"}
directive @deprecated(reason: String = "No longer supported") on
  FIELD_DEFINITION | ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION | ENUM_VALUE
```

## Arguments

| Argument | Type     | Default                 | Description                                                     |
| -------- | -------- | ----------------------- | --------------------------------------------------------------- |
| `reason` | `String` | `"No longer supported"` | Explains why the element is deprecated and what to use instead. |

## Overview

`@deprecated` is a built-in GraphQL directive defined in the
[GraphQL specification](https://spec.graphql.org/October2021/#sec--deprecated).
It signals to API consumers that a schema element should no longer be used.

Deprecated elements remain fully functional.
The directive is a documentation and tooling signal,
not a removal mechanism.
GraphQL IDEs such as GraphiQL display deprecation warnings,
and introspection exposes `isDeprecated` and `deprecationReason` fields
so tools can surface this information automatically.

### Supported locations

* **Field definitions** on object and interface types.
* **Argument definitions** on fields and directives.
* **Input field definitions** on input object types.
* **Enum values**.

## Examples

### Deprecating a field

```graphql theme={"system"}
type Product {
  id: ID!
  name: String!
  sku: String! @deprecated(reason: "Use `id` instead.")
}
```

### Deprecating an enum value

```graphql theme={"system"}
enum Status {
  ACTIVE
  INACTIVE @deprecated(reason: "Use ARCHIVED.")
  ARCHIVED
}
```

### Deprecating a field argument

```graphql theme={"system"}
type Query {
  users(
    limit: Int
    first: Int @deprecated(reason: "Use `limit`.")
  ): [User!]!
}
```

### Deprecating an input field

```graphql theme={"system"}
input CreateUserInput {
  name: String!
  username: String @deprecated(reason: "Usernames are auto-generated.")
}
```

## Federation behavior

During composition,
if the same field or enum value is marked `@deprecated` in multiple subgraphs with different reasons,
Cosmo keeps the longest reason string.

`@deprecated` is preserved in both the client-facing schema and the router schema.
It appears in introspection responses so that consumers can detect deprecated usage.