# `ExAzureCore.Auth`

Authentication module for Azure services.

Provides credential server management and token acquisition functionality.

# `child_spec`

```elixir
@spec child_spec(keyword()) :: Supervisor.child_spec()
```

Returns a child spec for starting the credential server under a supervisor.

## Examples

    children = [
      {ExAzureIdentity,
        name: MyApp.AzureToken,
        source: {:client_assertion, config}}
    ]

# `fetch`

```elixir
@spec fetch(term()) :: {:ok, map()} | {:error, term()}
```

Fetches the current token from a credential server.

Returns the cached token if available and still valid, otherwise fetches
a new one from the token source.

## Parameters

  * `name` - The name of the credential server

## Returns

  * `{:ok, token}` - A map containing the access token and metadata
  * `{:error, reason}` - An error tuple with the failure reason

## Examples

    {:ok, token} = ExAzureCore.Auth.fetch(MyApp.AzureToken)
    token.access_token
    #=> "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6Ik..."
    token.expires_at
    #=> 1234567890

# `fetch!`

```elixir
@spec fetch!(term()) :: map()
```

Fetches the current token from a credential server, raising on error.

## Parameters

  * `name` - The name of the credential server

## Returns

A map containing the access token and metadata.

## Raises

Raises a runtime error if the token cannot be fetched.

## Examples

    token = ExAzureCore.Auth.fetch!(MyApp.AzureToken)
    token.access_token
    #=> "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6Ik..."

# `start_link`

```elixir
@spec start_link(keyword()) :: GenServer.on_start()
```

Starts a credential server.

This function is typically called via a child spec in a supervision tree.

## Options

See module documentation for available options.

## Examples

    {:ok, pid} = ExAzureCore.Auth.start_link(
      name: :my_credential,
      source: {:client_assertion, %{
        tenant_id: "...",
        client_id: "...",
        scope: "https://graph.microsoft.com/.default",
        provider: :aws_cognito,
        provider_opts: [identity_id: "..."]
      }}
    )

---

*Consult [api-reference.md](api-reference.md) for complete listing*