# xAI Grok 4.3 API

> Grok 4.3 is an xAI reasoning model that xAI describes as fast and reliable, with strong tool calling and instruction following. It accepts text and image input with text output, offers a 1M-token context window, and supports configurable reasoning effort that can be switched off or raised, defaulting to low. It suits agentic workflows, long-document analysis and high-volume instruction-following tasks, while Grok 4.5 through 4.7 later took over as xAI's flagship for coding.

Source: https://www.sandbase.ai/models/x-ai/grok-4.3
API reference: https://www.sandbase.ai/models/x-ai/grok-4.3/docs

## Facts

- Provider: xAI
- Type: Language model
- Model ID: `x-ai/grok-4.3`
- Price: $1.25 per 1M input tokens, $2.50 per 1M output tokens
- Context window: 1M tokens, up to 1M 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`

```bash
curl -X POST https://api.sandbase.ai/v1/chat/completions \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "x-ai/grok-4.3",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ],
  "max_tokens": 2048
}'
```

## FAQ

### How do I call xAI Grok 4.3 through SandBase?

Create a SandBase API key, then send requests with the model ID "x-ai/grok-4.3" 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 xAI Grok 4.3 cost?

$1.25 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 xAI Grok 4.3?

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

### How does xAI Grok 4.3 score on benchmarks?

xAI Grok 4.3 scores 24.9 on the Artificial Analysis Intelligence Index (v4.3), ranking #50 of 83 models on SandBase; Coding Index 42.2, Agentic Index 15.5. Source: Artificial Analysis, measured as Grok 4.3 (High).

### Which features does xAI Grok 4.3 support?

xAI Grok 4.3 supports vision (image input), reasoning, function calling, structured output. See Specifications above for the full list.

### Do I need a separate xAI account?

No. One SandBase API key and balance gives you access to xAI Grok 4.3 and the other models in the catalog; you do not need to sign up with xAI separately.