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

# xAI

> xAI API conversion guide - OpenAI-compatible format, Grok models, vision support, reasoning, and parameter handling

## Overview

xAI is an **OpenAI-compatible provider** powering the Grok family of models. Bifrost delegates to the OpenAI implementation with standard parameter filtering. Key features:

* **Full OpenAI compatibility** - Chat, text completion, and responses
* **Vision support** - Image URLs and base64 encoding for multimodal models
* **Streaming support** - Server-Sent Events with delta-based updates
* **Reasoning support** - Extended thinking for Grok reasoning models
* **Tool calling** - Complete function definition and execution
* **Parameter filtering** - Removes unsupported OpenAI-specific fields

### Supported Operations

| Operation            | Non-Streaming | Streaming | Endpoint                 |
| -------------------- | ------------- | --------- | ------------------------ |
| Chat Completions     | ✅             | ✅         | `/v1/chat/completions`   |
| Responses API        | ✅             | ✅         | `/v1/responses`          |
| Text Completions     | ✅             | ✅         | `/v1/completions`        |
| Image Generation     | ✅             | -         | `/v1/images/generations` |
| List Models          | ✅             | -         | `/v1/models`             |
| Embeddings           | ❌             | ❌         | -                        |
| Speech (TTS)         | ❌             | ❌         | -                        |
| Transcriptions (STT) | ❌             | ❌         | -                        |
| Files                | ❌             | ❌         | -                        |
| Batch                | ❌             | ❌         | -                        |

<Note>
  **Unsupported Operations** (❌): Embeddings, Speech, Transcriptions, Files, and Batch are not supported by the upstream xAI API. These return `UnsupportedOperationError`.
</Note>

***

# 1. Chat Completions

## Request Parameters

xAI supports all standard OpenAI chat completion parameters. For full parameter reference and behavior, see [OpenAI Chat Completions](/providers/supported-providers/openai#1-chat-completions).

### Filtered Parameters

Removed for xAI compatibility:

* `prompt_cache_key` - Not supported
* `verbosity` - Anthropic-specific
* `store` - Not supported
* `service_tier` - Not supported

### Reasoning Support

xAI's `grok-3-mini` model supports extended reasoning via the standard `reasoning_effort` field:

```json theme={null}
{
  "model": "xai/grok-3-mini",
  "messages": [...],
  "reasoning_effort": "high"
}
```

<Warning>
  **Model-Specific Feature**: The `reasoning_effort` parameter is only supported by `grok-3-mini`. Other Grok-3 and Grok-4 models will return an error if this parameter is specified.
</Warning>

Bifrost converts from the internal `Reasoning` structure to xAI's `reasoning_effort` string format.

### Vision Support

xAI vision models support both image URLs and base64-encoded images:

```json theme={null}
{
  "model": "xai/grok-2-vision-1212",
  "messages": [{
    "role": "user",
    "content": [
      {"type": "text", "text": "What is in this image?"},
      {"type": "image_url", "image_url": {"url": "https://..."}}
    ]
  }]
}
```

**Supported Image Formats:**

* ✅ Image URLs
* ✅ Base64-encoded images
* ✅ Multiple images per message

xAI supports all standard OpenAI message types, tools, responses, and streaming formats. For details on message handling, tool conversion, responses, and streaming, refer to [OpenAI Chat Completions](/providers/supported-providers/openai#1-chat-completions).

***

# 2. Responses API

xAI's Responses API is forwarded directly to `/v1/responses`:

```
ResponsesRequest → /v1/responses → ResponsesResponse
```

Same parameter support and message handling as Chat Completions. Full streaming support available.

***

# 3. Text Completions

xAI supports legacy text completion format:

| Parameter                               | Mapping             |
| --------------------------------------- | ------------------- |
| `prompt`                                | Direct pass-through |
| `max_tokens`                            | max\_tokens         |
| `temperature`, `top_p`                  | Direct pass-through |
| `stop`                                  | Stop sequences      |
| `frequency_penalty`, `presence_penalty` | Penalty parameters  |

Streaming support available via `stream: true`.

***

# 4. Image Generation

xAI's image generation uses the OpenAI-compatible format.

**Request Conversion**

xAI uses the same conversion as OpenAI (see [OpenAI Image Generation](/providers/supported-providers/openai#7-image-generation)):

* **Model & Prompt**: `bifrostReq.Model` → `req.Model`, `bifrostReq.Prompt` → `req.Prompt`
* **Parameters**: All fields from `bifrostReq` (`ImageGenerationParameters`) are embedded directly into the request struct via struct embedding
* **Endpoint**: `/v1/images/generations`

<Note>
  **Note** : `quality`, `size` and `style` parameters are not supported by xAI's API at the moment.
</Note>

**Response Conversion**

Responses are unmarshaled directly into `BifrostImageGenerationResponse`.

**Streaming**: Image generation streaming is not supported by xAI.

***

# 5. List Models

Lists available xAI models with their capabilities and context lengths.

***

## Unsupported Features

| Feature           | Reason                 |
| ----------------- | ---------------------- |
| Embedding         | Not offered by xAI API |
| Speech/TTS        | Not offered by xAI API |
| Transcription/STT | Not offered by xAI API |
| Batch Operations  | Not offered by xAI API |
| File Management   | Not offered by xAI API |

***