> ## 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.

# Nebius

> Nebius API conversion guide - OpenAI-compatible format, parameter handling, streaming, embeddings, and special features

## Overview

Nebius is an **OpenAI-compatible provider** offering comprehensive API support. Bifrost delegates to the OpenAI implementation with standard parameter filtering. Key features:

* **Full OpenAI compatibility** - Chat, text completion, embeddings, and responses
* **Streaming support** - Server-Sent Events with delta-based updates
* **AI Project ID** - Nebius-specific project identifier support
* **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/chat/completions`   |
| Text Completions     | ✅             | ✅         | `/v1/completions`        |
| Embeddings           | ✅             | -         | `/v1/embeddings`         |
| Image Generation     | ✅             | -         | `/v1/images/generations` |
| List Models          | ✅             | -         | `/v1/models`             |
| Speech (TTS)         | ❌             | ❌         | -                        |
| Transcriptions (STT) | ❌             | ❌         | -                        |
| Files                | ❌             | ❌         | -                        |
| Batch                | ❌             | ❌         | -                        |

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

***

# 1. Chat Completions

## Request Parameters

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

### Nebius-Specific Parameters

**ai\_project\_id (Optional):**

Nebius allows specifying a project ID for resource organization:

<Tabs>
  <Tab title="Gateway">
    ```bash theme={null}
    curl -X POST http://localhost:8080/v1/chat/completions \
      -H "Content-Type: application/json" \
      -d '{
        "model": "nebius/model-name",
        "messages": [...],
        "ai_project_id": "project-123"
      }'
    ```
  </Tab>

  <Tab title="Go SDK">
    ```go theme={null}
    request := &schemas.BifrostChatRequest{
        Model: "model-name",
        Input: messages,
        Params: &schemas.ChatParameters{
            ExtraParams: map[string]interface{}{
                "ai_project_id": "project-123",
            },
        },
    }
    ```
  </Tab>
</Tabs>

The `ai_project_id` is appended as a query parameter to the request URL.

### Filtered Parameters

Removed for Nebius compatibility:

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

Nebius 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

Converted internally to Chat Completions:

```
ResponsesRequest → ChatRequest → ChatCompletion → ResponsesResponse
```

Same parameter support and message handling as Chat Completions. Supports ai\_project\_id via extra\_params.

***

# 3. Text Completions

Nebius 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  |

***

# 4. Embeddings

Nebius supports text embeddings:

| Parameter         | Notes                               |
| ----------------- | ----------------------------------- |
| `input`           | Text or array of texts              |
| `model`           | Embedding model name                |
| `encoding_format` | "float" or "base64"                 |
| `dimensions`      | Custom output dimensions (optional) |

Response returns embedding vectors with usage information.

***

# 5. Image Generation

**Request Parameters**

| Parameter             | Type   | Required | Notes                                                                                               |
| --------------------- | ------ | -------- | --------------------------------------------------------------------------------------------------- |
| `model`               | string | ✅        | Model identifier                                                                                    |
| `prompt`              | string | ✅        | Text description of the image to generate                                                           |
| `size`                | string | ❌        | Image size in WxH format (e.g., `"1024x1024"`). Converted to separate `width` and `height` integers |
| `output_format`       | string | ❌        | Output format: `"png"`, `"jpeg"`, `"webp"`. Note: `"jpeg"` is converted to `"jpg"`                  |
| `response_format`     | string | ❌        | Response format: `"url"` or `"b64_json"`                                                            |
| `seed`                | int    | ❌        | Seed for reproducible generation                                                                    |
| `negative_prompt`     | string | ❌        | Negative prompt                                                                                     |
| `num_inference_steps` | int    | ❌        | Number of inference steps                                                                           |
| `extra_params`        | object | ❌        | Nebius-specific parameters (see below)                                                              |

**Extra Parameters (via `extra_params`)**

| Parameter        | Type   | Notes                                        |
| ---------------- | ------ | -------------------------------------------- |
| `guidance_scale` | int    | Guidance scale (0-100)                       |
| `ai_project_id`  | string | Nebius project ID (added as query parameter) |

***

**Request Conversion**

* **Model & Prompt**: `bifrostReq.Model` → `req.Model` (pointer), `bifrostReq.Input.Prompt` → `req.Prompt` (pointer)
* **Size Conversion**: `params.size` (WxH format like `"1024x1024"`) is split into:
  * `width`: Integer extracted from first part (e.g., `1024`)
  * `height`: Integer extracted from second part (e.g., `1024`)
* **Output Format**:
  * `params.output_format` → `req.ResponseExtension`
  * Special conversion: `"jpeg"` → `"jpg"` (Nebius uses `"jpg"` not `"jpeg"`)
* **Response Format**: `params.response_format` → `req.ResponseFormat` (passed directly: `"url"` or `"b64_json"`)
* **Seed & Negative Prompt**: `params.seed` → `req.Seed`, `params.negative_prompt` → `req.NegativePrompt` (passed directly)
* **Num Inference Steps**: `params.num_inference_steps` → `req.NumInferenceSteps` (passed directly)
* **Extra Parameters**:
  * `guidance_scale` → `req.GuidanceScale` (int pointer)
  * `ai_project_id` → Added as query parameter `?ai_project_id={value}` to the request URL

**Response Conversion**

* **Image Data**: Each item in `response.data[]` → `ImageData` with:
  * `url`: From `data[].url`
  * `b64_json`: From `data[].b64_json`
  * `revised_prompt`: From `data[].revised_prompt`
  * `index`: Sequential index (0, 1, 2, ...)
* **ID**: `response.id` → `response.ID`
* **Provider**: Set to `nebius` in `ExtraFields`

**Endpoint**: `/v1/images/generations`

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

***

# 6. List Models

Lists available Nebius models with capabilities and context lengths.

***

## Unsupported Features

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

***

## Caveats

<Accordion title="Cache Control Stripped">
  **Severity**: Medium
  **Behavior**: Cache control directives are removed from messages
  **Impact**: Prompt caching features don't work
  **Code**: Stripped during JSON marshaling
</Accordion>

<Accordion title="Parameter Filtering">
  **Severity**: Low
  **Behavior**: OpenAI-specific fields filtered out
  **Impact**: prompt\_cache\_key, verbosity, store removed
  **Code**: filterOpenAISpecificParameters
</Accordion>

<Accordion title="User Field Size Limit">
  **Severity**: Low
  **Behavior**: User field > 64 characters silently dropped
  **Impact**: Longer user identifiers are lost
  **Code**: SanitizeUserField enforces 64-char max
</Accordion>