---
title: Anthropic
description: Use Anthropic Claude models with Nexus — vision, tools, and extended thinking.
---

The Anthropic provider connects to the Anthropic Messages API for chat completions, streaming, vision, tool calling, and extended thinking.

## Installation

```go
import "github.com/xraph/nexus/providers/anthropic"
```

## Quick Start

```go
provider := anthropic.New(os.Getenv("ANTHROPIC_API_KEY"))

gw := nexus.New(
    nexus.WithProvider(provider),
)
```

## Options

| Option | Description |
|--------|-------------|
| `anthropic.WithBaseURL(url)` | Override the API base URL (default: `https://api.anthropic.com`) |

## Capabilities

| Capability | Supported |
|-----------|-----------|
| Chat | Yes |
| Streaming | Yes |
| Embeddings | No |
| Vision | Yes |
| Tools | Yes |
| Thinking | Yes |

## Models

| Model | Context | Max Output | Input Price | Output Price |
|-------|---------|-----------|-------------|-------------|
| `claude-sonnet-4-5-20250514` | 200K | 8,192 | $3.00/M | $15.00/M |
| `claude-opus-4-5-20250630` | 200K | 8,192 | $15.00/M | $75.00/M |
| `claude-3-5-haiku-20241022` | 200K | 8,192 | $0.80/M | $4.00/M |
| `claude-3-5-sonnet-20241022` | 200K | 8,192 | $3.00/M | $15.00/M |