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

# Anthropic SDK

> anthropic-py, anthropic-ts — point at qlaud, get cache_control + thinking blocks preserved verbatim.

qlaud's `/v1/messages` endpoint is a **native passthrough** for Anthropic
upstreams. The body forwards verbatim — `cache_control: ephemeral` markers,
image content blocks, and thinking blocks all preserved.

## Python

```python theme={null}
from anthropic import Anthropic

client = Anthropic(
    base_url="https://api.qlaud.ai",
    api_key="qlk_live_...",
)

msg = client.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=1024,
    messages=[{"role": "user", "content": "hello"}],
)
print(msg.content[0].text)
```

## Node

```typescript theme={null}
import Anthropic from '@anthropic-ai/sdk';

const client = new Anthropic({
  baseURL: 'https://api.qlaud.ai',
  apiKey: 'qlk_live_...',
});

const msg = await client.messages.create({
  model: 'claude-sonnet-4-6',
  max_tokens: 1024,
  messages: [{ role: 'user', content: 'hello' }],
});
console.log(msg.content);
```

## Prompt cache (the headline feature)

`cache_control` markers are forwarded to Anthropic verbatim. Tag a system
block as ephemeral once, save 75% input cost on every subsequent turn.

```python theme={null}
client.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=1024,
    system=[
        {
            "type": "text",
            "text": LONG_SYSTEM_PROMPT,
            "cache_control": {"type": "ephemeral"},
        }
    ],
    messages=[{"role": "user", "content": "hello"}],
)
```

The first call writes the cache. Every subsequent call within \~5 minutes
reads from cache at \~25% of the input price.

## Cross-provider via Anthropic shape

You can pass non-Anthropic model slugs too — qlaud translates the body
to the upstream's shape automatically:

```python theme={null}
msg = client.messages.create(
    model="gpt-5.4",          # routed to OpenAI
    max_tokens=1024,
    messages=[{"role": "user", "content": "hello"}],
)
```

For pure Anthropic calls (Opus, Sonnet, Haiku) the request flows verbatim
with no translation overhead.

## Tool use

Native — same Anthropic shape. Tool definitions, `tool_use` content blocks,
`tool_result` content blocks all forwarded.