# Anthropic Claude Opus 4.6 API

> Opus 4.6 is Anthropic’s strongest model for coding and long-running professional tasks. It is built for agents that operate across entire workflows rather than single prompts, making it especially effective for large codebases, complex refactors, and multi-step debugging that unfolds over time. The model shows deeper contextual understanding, stronger problem decomposition, and greater reliability on hard engineering tasks than prior generations. Beyond coding, Opus 4.6 excels at sustained knowledge work. It produces near-production-ready documents, plans, and analyses in a single pass, and maintains coherence across very long outputs and extended sessions. This makes it a strong default for tasks that require persistence, judgment, and follow-through, such as technical design, migration planning, and end-to-end project execution. For users upgrading from earlier Opus versions, see our [official migration guide here](https://openrouter.ai/docs/guides/guides/model-migrations/claude-4-6-opus)

Source: https://www.sandbase.ai/models/anthropic/claude-opus-4.6
API reference: https://www.sandbase.ai/models/anthropic/claude-opus-4.6/docs

## Facts

- Provider: Anthropic
- Type: Language model
- Model ID: `anthropic/claude-opus-4.6`
- Price: $5 per 1M input tokens, $25 per 1M output tokens
- Context window: 1M tokens, up to 128K output tokens
- Capabilities: chat, vision, reasoning, structured output, function calling
- Billing: pay per use from one SandBase balance; no provider account or subscription needed

## Call it

- Chat Completions API: `POST https://api.sandbase.ai/v1/chat/completions`
- Messages API: `POST https://api.sandbase.ai/v1/messages`

```bash
curl -X POST https://api.sandbase.ai/v1/chat/completions \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "anthropic/claude-opus-4.6",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ],
  "max_tokens": 2048
}'
```

## FAQ

### How do I call Anthropic Claude Opus 4.6 through SandBase?

Create a SandBase API key, then send requests with the model ID "anthropic/claude-opus-4.6" to Chat Completions API (/v1/chat/completions) or Messages API (/v1/messages) at https://api.sandbase.ai. The request examples on this page show the exact payload.

### How much does Anthropic Claude Opus 4.6 cost?

$5 per 1M input tokens and $25 per 1M output tokens, billed per request from your SandBase balance. Discounts, when available, are shown in the pricing on this page.

### What is the context window of Anthropic Claude Opus 4.6?

1M tokens of context, with up to 128K output tokens per response.

### How does Anthropic Claude Opus 4.6 score on benchmarks?

Anthropic Claude Opus 4.6 scores 31.9 on the Artificial Analysis Intelligence Index (v4.3), ranking #39 of 83 models on SandBase. Source: Artificial Analysis, measured as Claude Opus 4.6 (Max).

### Which features does Anthropic Claude Opus 4.6 support?

Anthropic Claude Opus 4.6 supports vision (image input), reasoning, function calling, structured output. See Specifications above for the full list.

### Do I need a separate Anthropic account?

No. One SandBase API key and balance gives you access to Anthropic Claude Opus 4.6 and the other models in the catalog; you do not need to sign up with Anthropic separately.