# `ClaudeAgentSDK.Auth.Providers.Vertex`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.21.0/lib/claude_agent_sdk/auth/providers/vertex.ex#L1)

Google Vertex AI authentication.

Uses GCP credentials instead of Anthropic API keys.
Requires CLAUDE_AGENT_USE_VERTEX=1 environment variable.

# `setup_token`

```elixir
@spec setup_token() :: {:ok, String.t(), nil} | {:error, term()}
```

Validates Google Vertex AI authentication.

Returns {:ok, "gcp", nil} if GCP credentials are available.
No token needed - CLI uses GCP SDK authentication.

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