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

# Claude Sonnet 4.5

> Anthropic's Claude Sonnet 4.5 language model

Claude Sonnet 4.5 is Anthropic's balanced model offering strong performance at efficient cost for a wide range of tasks.

## Model

```
anthropic/claude-sonnet-4-5
```

|              |                   |
| ------------ | ----------------- |
| **Provider** | Anthropic         |
| **Name**     | Claude Sonnet 4.5 |

## Supported Endpoints

All three API formats are supported:

* [Chat Completions](/api-reference/v1-chat-completions) — `POST /v1/chat/completions`
* [Responses](/api-reference/v1-responses) — `POST /v1/responses`
* [Messages](/api-reference/v1-messages) — `POST /v1/messages`

## Example

```bash theme={null}
curl -X POST https://api.unifically.com/v1/messages \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "anthropic/claude-sonnet-4-5",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Review this function for potential bugs."}
    ]
  }'
```