# Tencent Hy4 preview API

> Hy4 preview is Tencent Hunyuan's open-source preview of its Hy4 generation, a mixture-of-experts language model with 770B total and 49B active parameters and a context window exceeding 1M tokens. Tencent built it for real-world productivity: long-context software development and front-end work, office and financial analysis, game prototyping and scientific research. Tencent follows a preview-first approach, with official Hy4 releases to come after this model.

Source: https://www.sandbase.ai/models/tencent/hy4-preview
API reference: https://www.sandbase.ai/models/tencent/hy4-preview/docs

## Facts

- Provider: Tencent
- Type: Language model
- Model ID: `tencent/hy4-preview`
- Price: $0.83 per 1M input tokens, $2.50 per 1M output tokens
- Context window: 1M tokens, up to 64K output tokens
- Capabilities: chat, 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`

```bash
curl -X POST https://api.sandbase.ai/v1/chat/completions \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "tencent/hy4-preview",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ],
  "max_tokens": 2048
}'
```

## FAQ

### How do I call Tencent Hy4 preview through SandBase?

Create a SandBase API key, then send requests with the model ID "tencent/hy4-preview" to Chat Completions API (/v1/chat/completions) at https://api.sandbase.ai. The request examples on this page show the exact payload.

### How much does Tencent Hy4 preview cost?

$0.83 per 1M input tokens and $2.50 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 Tencent Hy4 preview?

1M tokens of context, with up to 64K output tokens per response.

### Which features does Tencent Hy4 preview support?

Tencent Hy4 preview supports reasoning, function calling, structured output. See Specifications above for the full list.

### Do I need a separate Tencent account?

No. One SandBase API key and balance gives you access to Tencent Hy4 preview and the other models in the catalog; you do not need to sign up with Tencent separately.