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

# Claude Opus 4.8

> Call Anthropic's Claude Opus 4.8 via OpenAI-compatible interface — the most capable general-purpose model, with adaptive thinking and fast mode.

Claude Opus 4.8 is Anthropic's most capable general-purpose model, available through Starrise AI via OpenAI-compatible interface. Built on Claude Opus 4.7, it features improvements in long-horizon agentic coding, tool-trigger reliability, and compression handling.

## Key Capabilities

* **OpenAI-compatible** — Drop-in replacement for the OpenAI SDK, no other code changes needed
* **1M context window** — 128K max output tokens
* **Adaptive thinking** — Triggers reasoning only when the task requires it, reducing unnecessary thinking tokens
* **Fast mode** — Up to 2.5× output speed (research preview, premium pricing)
* **In-conversation system messages** — Append updated instructions without resending the full system prompt
* **Lower cache threshold** — Minimum cacheable prompt length reduced to 1,024 tokens
* **Streaming** — Real-time token streaming via SSE

## Quick Example

<CodeGroup>
  ```bash cURL theme={null}
  curl https://ai.alad.com/v1/messages \
    -H "Authorization: Bearer YOUR_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "model": "claude-opus-4-8",
      "messages": [
        { "role": "user", "content": "Explain quantum entanglement in simple terms." }
      ]
    }'
  ```

  ```python Python theme={null}
  from openai import OpenAI

  client = OpenAI(
      api_key="YOUR_API_KEY",
      base_url="https://ai.alad.com/v1"
  )

  response = client.chat.completions.create(
      model="claude-opus-4-8",
      messages=[
          {"role": "user", "content": "Explain quantum entanglement in simple terms."}
      ]
  )

  print(response.choices[0].message.content)
  ```

  ```python Streaming theme={null}
  from openai import OpenAI

  client = OpenAI(
      api_key="YOUR_API_KEY",
      base_url="https://ai.alad.com/v1"
  )

  stream = client.chat.completions.create(
      model="claude-opus-4-8",
      messages=[
          {"role": "user", "content": "Write a short poem about the ocean."}
      ],
      stream=True
  )

  for chunk in stream:
      print(chunk.choices[0].delta.content or "", end="")
  ```
</CodeGroup>

## Parameters

| Parameter    | Type           | Required | Description                           |
| ------------ | -------------- | -------- | ------------------------------------- |
| `model`      | string         | Yes      | Fixed value: `claude-opus-4-8`        |
| `messages`   | array          | Yes      | Array of `{ role, content }` objects  |
| `max_tokens` | integer        | No       | Maximum number of tokens to generate  |
| `stream`     | boolean        | No       | Enable SSE streaming, default `false` |
| `stop`       | string / array | No       | Sequences where generation stops      |

<Note>
  Claude Opus 4.8 does not support `temperature`, `top_p`, and `top_k` parameters. Setting non-default values returns a 400 error — guide model behavior through prompts instead.
</Note>

<Card title="API Reference" icon="code" href="/en/api-reference/model-api/anthropic/claude-opus-4-8">
  View the interactive API Playground for Claude Opus 4.8.
</Card>