# `ClaudeAgentSDK.Config.Auth`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.17.2/lib/claude_agent_sdk/config/auth.ex#L1)

Authentication configuration: file paths, TTLs, and token prefixes.

Runtime overrides via Application config:

    config :claude_agent_sdk, ClaudeAgentSDK.Config.Auth,
      token_store_path: "~/.my_sdk/token.json",
      session_max_age_days: 60

# `api_key_prefix`

```elixir
@spec api_key_prefix() :: String.t()
```

API key prefix for validation.

# `aws_credentials_path`

```elixir
@spec aws_credentials_path() :: String.t()
```

AWS credentials file path (default: `~/.aws/credentials`).

# `gcp_credentials_path`

```elixir
@spec gcp_credentials_path() :: String.t()
```

GCP application default credentials path.

# `oauth_token_prefix`

```elixir
@spec oauth_token_prefix() :: String.t()
```

OAuth token prefix for validation.

# `providers`

```elixir
@spec providers() :: [:anthropic | :bedrock | :vertex]
```

List of supported auth provider atoms.

# `session_max_age_days`

```elixir
@spec session_max_age_days() :: pos_integer()
```

Maximum session age in days (default: 30).

# `session_storage_dir`

```elixir
@spec session_storage_dir() :: String.t()
```

Default session storage directory (default: `~/.claude_sdk/sessions`).

# `token_store_path`

```elixir
@spec token_store_path() :: String.t()
```

Default token storage path (default: `~/.claude_sdk/token.json`).

# `token_ttl_days`

```elixir
@spec token_ttl_days() :: pos_integer()
```

Token validity period in days (default: 365).

---

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