
+++
disableToc = false
title = "Text Generation (GPT)"
weight = 10
url = "/features/text-generation/"
+++

LocalAI supports generating text with GPT with `llama.cpp` and other backends (such as `rwkv.cpp` as ) see also the [Model compatibility]({{%relref "reference/compatibility-table" %}}) for an up-to-date list of the supported model families.

Note:

- You can also specify the model name as part of the OpenAI token.
- If only one model is available, the API will use it for all the requests.

## API Reference

### Chat completions

https://platform.openai.com/docs/api-reference/chat

For example, to generate a chat completion, you can send a POST request to the `/v1/chat/completions` endpoint with the instruction as the request body:

```bash
curl http://localhost:8080/v1/chat/completions -H "Content-Type: application/json" -d '{
  "model": "ggml-koala-7b-model-q4_0-r2.bin",
  "messages": [{"role": "user", "content": "Say this is a test!"}],
  "temperature": 0.7
}'
```

Available additional parameters: `top_p`, `top_k`, `max_tokens`

### Edit completions

https://platform.openai.com/docs/api-reference/edits

To generate an edit completion you can send a POST request to the `/v1/edits` endpoint with the instruction as the request body:

```bash
curl http://localhost:8080/v1/edits -H "Content-Type: application/json" -d '{
  "model": "ggml-koala-7b-model-q4_0-r2.bin",
  "instruction": "rephrase",
  "input": "Black cat jumped out of the window",
  "temperature": 0.7
}'
```

Available additional parameters: `top_p`, `top_k`, `max_tokens`.

### Completions

https://platform.openai.com/docs/api-reference/completions

To generate a completion, you can send a POST request to the `/v1/completions` endpoint with the instruction as per the request body:

```bash
curl http://localhost:8080/v1/completions -H "Content-Type: application/json" -d '{
  "model": "ggml-koala-7b-model-q4_0-r2.bin",
  "prompt": "A long time ago in a galaxy far, far away",
  "temperature": 0.7
}'
```

Available additional parameters: `top_p`, `top_k`, `max_tokens`

### List models

You can list all the models available with:

```bash
curl http://localhost:8080/v1/models
```

### Anthropic Messages API

LocalAI supports the Anthropic Messages API, which is compatible with Claude clients. This endpoint provides a structured way to send messages and receive responses, with support for tools, streaming, and multimodal content.

**Endpoint:** `POST /v1/messages` or `POST /messages`

**Reference:** https://docs.anthropic.com/claude/reference/messages_post

#### Basic Usage

```bash
curl http://localhost:8080/v1/messages \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Say this is a test!"}
    ]
  }'
```

#### Request Parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `model` | string | Yes | The model identifier |
| `messages` | array | Yes | Array of message objects with `role` and `content` |
| `max_tokens` | integer | Yes | Maximum number of tokens to generate (must be > 0) |
| `system` | string | No | System message to set the assistant's behavior |
| `temperature` | float | No | Sampling temperature (0.0 to 1.0) |
| `top_p` | float | No | Nucleus sampling parameter |
| `top_k` | integer | No | Top-k sampling parameter |
| `stop_sequences` | array | No | Array of strings that will stop generation |
| `stream` | boolean | No | Enable streaming responses |
| `tools` | array | No | Array of tool definitions for function calling |
| `tool_choice` | string/object | No | Tool choice strategy: "auto", "any", "none", or specific tool |
| `metadata` | object | No | Per-request metadata passed to the backend (e.g., `{"enable_thinking": "true"}`) |

#### Message Format

Messages can contain text or structured content blocks:

```bash
curl http://localhost:8080/v1/messages \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "max_tokens": 1024,
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "text",
            "text": "What is in this image?"
          },
          {
            "type": "image",
            "source": {
              "type": "base64",
              "media_type": "image/jpeg",
              "data": "base64_encoded_image_data"
            }
          }
        ]
      }
    ]
  }'
```

#### Tool Calling

The Anthropic API supports function calling through tools:

```bash
curl http://localhost:8080/v1/messages \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "max_tokens": 1024,
    "tools": [
      {
        "name": "get_weather",
        "description": "Get the current weather",
        "input_schema": {
          "type": "object",
          "properties": {
            "location": {
              "type": "string",
              "description": "The city and state"
            }
          },
          "required": ["location"]
        }
      }
    ],
    "tool_choice": "auto",
    "messages": [
      {"role": "user", "content": "What is the weather in San Francisco?"}
    ]
  }'
```

#### Streaming

Enable streaming responses by setting `stream: true`:

```bash
curl http://localhost:8080/v1/messages \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "max_tokens": 1024,
    "stream": true,
    "messages": [
      {"role": "user", "content": "Tell me a story"}
    ]
  }'
```

Streaming responses use Server-Sent Events (SSE) format with event types: `message_start`, `content_block_start`, `content_block_delta`, `content_block_stop`, `message_delta`, and `message_stop`.

#### Response Format

```json
{
  "id": "msg_abc123",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "This is a test!"
    }
  ],
  "model": "ggml-koala-7b-model-q4_0-r2.bin",
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 10,
    "output_tokens": 5
  }
}
```

### Open Responses API

LocalAI supports the Open Responses API specification, which provides a standardized interface for AI model interactions with support for background processing, streaming, tool calling, and advanced features like reasoning.

**Endpoint:** `POST /v1/responses` or `POST /responses`

**Reference:** https://www.openresponses.org/specification

#### Basic Usage

```bash
curl http://localhost:8080/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "input": "Say this is a test!",
    "max_output_tokens": 1024
  }'
```

#### Request Parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `model` | string | Yes | The model identifier |
| `input` | string/array | Yes | Input text or array of input items |
| `max_output_tokens` | integer | No | Maximum number of tokens to generate |
| `temperature` | float | No | Sampling temperature |
| `top_p` | float | No | Nucleus sampling parameter |
| `instructions` | string | No | System instructions |
| `tools` | array | No | Array of tool definitions |
| `tool_choice` | string/object | No | Tool choice: "auto", "required", "none", or specific tool |
| `stream` | boolean | No | Enable streaming responses |
| `background` | boolean | No | Run request in background (returns immediately) |
| `store` | boolean | No | Whether to store the response |
| `reasoning` | object | No | Reasoning configuration with `effort` and `summary` |
| `parallel_tool_calls` | boolean | No | Allow parallel tool calls |
| `max_tool_calls` | integer | No | Maximum number of tool calls |
| `presence_penalty` | float | No | Presence penalty (-2.0 to 2.0) |
| `frequency_penalty` | float | No | Frequency penalty (-2.0 to 2.0) |
| `top_logprobs` | integer | No | Number of top logprobs to return |
| `truncation` | string | No | Truncation mode: "auto" or "disabled" |
| `text_format` | object | No | Text format configuration |
| `metadata` | object | No | Custom metadata |

#### Input Format

Input can be a simple string or an array of structured items:

```bash
curl http://localhost:8080/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "input": [
      {
        "type": "message",
        "role": "user",
        "content": "What is the weather?"
      }
    ],
    "max_output_tokens": 1024
  }'
```

#### Background Processing

Run requests in the background for long-running tasks:

```bash
curl http://localhost:8080/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "input": "Generate a long story",
    "max_output_tokens": 4096,
    "background": true
  }'
```

The response will include a response ID that can be used to poll for completion:

```json
{
  "id": "resp_abc123",
  "object": "response",
  "status": "in_progress",
  "created_at": 1234567890
}
```

#### Retrieving Background Responses

Use the GET endpoint to retrieve background responses:

```bash
# Get response by ID
curl http://localhost:8080/v1/responses/resp_abc123

# Resume streaming with query parameters
curl "http://localhost:8080/v1/responses/resp_abc123?stream=true&starting_after=10"
```

#### Canceling Background Responses

Cancel a background response that's still in progress:

```bash
curl -X POST http://localhost:8080/v1/responses/resp_abc123/cancel
```

#### Tool Calling

Open Responses API supports function calling with tools:

```bash
curl http://localhost:8080/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "input": "What is the weather in San Francisco?",
    "tools": [
      {
        "type": "function",
        "name": "get_weather",
        "description": "Get the current weather",
        "parameters": {
          "type": "object",
          "properties": {
            "location": {
              "type": "string",
              "description": "The city and state"
            }
          },
          "required": ["location"]
        }
      }
    ],
    "tool_choice": "auto",
    "max_output_tokens": 1024
  }'
```

#### Reasoning Configuration

Configure reasoning effort and summary style:

```bash
curl http://localhost:8080/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ggml-koala-7b-model-q4_0-r2.bin",
    "input": "Solve this complex problem step by step",
    "reasoning": {
      "effort": "high",
      "summary": "detailed"
    },
    "max_output_tokens": 2048
  }'
```

#### Response Format

```json
{
  "id": "resp_abc123",
  "object": "response",
  "created_at": 1234567890,
  "completed_at": 1234567895,
  "status": "completed",
  "model": "ggml-koala-7b-model-q4_0-r2.bin",
  "output": [
    {
      "type": "message",
      "id": "msg_001",
      "role": "assistant",
      "content": [
        {
          "type": "output_text",
          "text": "This is a test!",
          "annotations": [],
          "logprobs": []
        }
      ],
      "status": "completed"
    }
  ],
  "error": null,
  "incomplete_details": null,
  "temperature": 0.7,
  "top_p": 1.0,
  "presence_penalty": 0.0,
  "frequency_penalty": 0.0,
  "usage": {
    "input_tokens": 10,
    "output_tokens": 5,
    "total_tokens": 15,
    "input_tokens_details": {
      "cached_tokens": 0
    },
    "output_tokens_details": {
      "reasoning_tokens": 0
    }
  }
}
```

## Backends

### RWKV

RWKV support is available through llama.cpp (see below)

### llama.cpp

[llama.cpp](https://github.com/ggerganov/llama.cpp) is a popular port of Facebook's LLaMA model in C/C++.

{{% notice note %}}

The `ggml` file format has been deprecated. If you are using `ggml` models and you are configuring your model with a YAML file, specify, use a LocalAI version older than v2.25.0. For `gguf` models, use the `llama` backend. The go backend is deprecated as well but still available as `go-llama`.

 {{% /notice %}}

#### Features

The `llama.cpp` model supports the following features:
- [📖 Text generation (GPT)]({{%relref "features/text-generation" %}})
- [🧠 Embeddings]({{%relref "features/embeddings" %}})
- [🔥 OpenAI functions]({{%relref "features/openai-functions" %}})
- [✍️ Constrained grammars]({{%relref "features/constrained_grammars" %}})

#### Setup

LocalAI supports `llama.cpp` models out of the box. You can use the `llama.cpp` model in the same way as any other model. 

##### Manual setup

It is sufficient to copy the `ggml` or `gguf` model files in the `models` folder. You can refer to the model in the `model` parameter in the API calls.

[You can optionally create an associated YAML]({{%relref "advanced" %}}) model config file to tune the model's parameters or apply a template to the prompt.

Prompt templates are useful for models that are fine-tuned towards a specific prompt. 

##### Automatic setup

LocalAI supports model galleries which are indexes of models. For instance, the huggingface gallery contains a large curated index of models from the huggingface model hub for `ggml` or `gguf` models.

For instance, if you have the galleries enabled and LocalAI already running, you can just start chatting with models in huggingface by running:

```bash
curl http://localhost:8080/v1/chat/completions -H "Content-Type: application/json" -d '{
     "model": "TheBloke/WizardLM-13B-V1.2-GGML/wizardlm-13b-v1.2.ggmlv3.q2_K.bin",
     "messages": [{"role": "user", "content": "Say this is a test!"}],
     "temperature": 0.1
   }'
```

LocalAI will automatically download and configure the model in the `model` directory.

Models can be also preloaded or downloaded on demand. To learn about model galleries, check out the [model gallery documentation]({{%relref "features/model-gallery" %}}).

#### YAML configuration

To use the `llama.cpp` backend, specify `llama-cpp` as the backend in the YAML file:

```yaml
name: llama
backend: llama-cpp
parameters:
  # Relative to the models path
  model: file.gguf
```

#### Backend Options

The `llama.cpp` backend supports additional configuration options that can be specified in the `options` field of your model YAML configuration. These options allow fine-tuning of the backend behavior:

| Option | Type | Description | Example |
|--------|------|-------------|---------|
| `use_jinja` or `jinja` | boolean | Enable Jinja2 template processing for chat templates. When enabled, the backend uses Jinja2-based chat templates from the model for formatting messages. | `use_jinja:true` |
| `context_shift` | boolean | Enable context shifting, which allows the model to dynamically adjust context window usage. | `context_shift:true` |
| `cache_ram` | integer | Set the maximum RAM cache size in MiB for KV cache. Use `-1` for unlimited (default). | `cache_ram:2048` |
| `parallel` or `n_parallel` | integer | Enable parallel request processing. When set to a value greater than 1, enables continuous batching for handling multiple requests concurrently. | `parallel:4` |
| `grpc_servers` or `rpc_servers` | string | Comma-separated list of gRPC server addresses for distributed inference. Allows distributing workload across multiple llama.cpp workers. | `grpc_servers:localhost:50051,localhost:50052` |
| `fit_params` or `fit` | boolean | Enable auto-adjustment of model/context parameters to fit available device memory. Default: `true`. | `fit_params:true` |
| `fit_params_target` or `fit_target` | integer | Target margin per device in MiB when using fit_params. Default: `1024` (1GB). | `fit_target:2048` |
| `fit_params_min_ctx` or `fit_ctx` | integer | Minimum context size that can be set by fit_params. Default: `4096`. | `fit_ctx:2048` |
| `n_cache_reuse` or `cache_reuse` | integer | Minimum chunk size to attempt reusing from the cache via KV shifting. Default: `0` (disabled). | `cache_reuse:256` |
| `slot_prompt_similarity` or `sps` | float | How much the prompt of a request must match the prompt of a slot to use that slot. Default: `0.1`. Set to `0` to disable. | `sps:0.5` |
| `swa_full` | boolean | Use full-size SWA (Sliding Window Attention) cache. Default: `false`. | `swa_full:true` |
| `cont_batching` or `continuous_batching` | boolean | Enable continuous batching for handling multiple sequences. Default: `true`. | `cont_batching:true` |
| `check_tensors` | boolean | Validate tensor data for invalid values during model loading. Default: `false`. | `check_tensors:true` |
| `warmup` | boolean | Enable warmup run after model loading. Default: `true`. | `warmup:false` |
| `no_op_offload` | boolean | Disable offloading host tensor operations to device. Default: `false`. | `no_op_offload:true` |
| `kv_unified` or `unified_kv` | boolean | Enable unified KV cache. Default: `false`. | `kv_unified:true` |
| `n_ctx_checkpoints` or `ctx_checkpoints` | integer | Maximum number of context checkpoints per slot. Default: `8`. | `ctx_checkpoints:4` |
| `split_mode` or `sm` | string | How to split the model across multiple GPUs: `none` (single GPU only), `layer` (default — split layers and KV across GPUs), `row` (split rows across GPUs), `tensor` (experimental tensor parallelism — requires `flash_attention: true`, no KV-cache quantization, manually set `context_size`, and a llama.cpp build that includes [#19378](https://github.com/ggml-org/llama.cpp/pull/19378)). | `split_mode:tensor` |

**Example configuration with options:**

```yaml
name: llama-model
backend: llama
parameters:
  model: model.gguf
options:
  - use_jinja:true
  - context_shift:true
  - cache_ram:4096
  - parallel:2
  - fit_params:true
  - fit_target:1024
  - slot_prompt_similarity:0.5
```

**Note:** The `parallel` option can also be set via the `LLAMACPP_PARALLEL` environment variable, and `grpc_servers` can be set via the `LLAMACPP_GRPC_SERVERS` environment variable. Options specified in the YAML file take precedence over environment variables.

#### Reference

- [llama](https://github.com/ggerganov/llama.cpp)


### ik_llama.cpp

[ik_llama.cpp](https://github.com/ikawrakow/ik_llama.cpp) is a hard fork of `llama.cpp` by Iwan Kawrakow that focuses on superior CPU and hybrid GPU/CPU performance. It ships additional quantization types (IQK quants), custom quantization mixes, Multi-head Latent Attention (MLA) for DeepSeek models, and fine-grained tensor offload controls — particularly useful for running very large models on commodity CPU hardware.

{{% notice note %}}

The `ik-llama-cpp` backend requires a CPU with **AVX2** support. The IQK kernels are not compatible with older CPUs.

{{% /notice %}}

#### Features

The `ik-llama-cpp` backend supports the following features:
- [📖 Text generation (GPT)]({{%relref "features/text-generation" %}})
- [🧠 Embeddings]({{%relref "features/embeddings" %}})
- IQK quantization types for better CPU inference performance
- Multimodal models (via clip/llava)

#### Setup

The backend is distributed as a separate container image and can be installed from the LocalAI backend gallery, or specified directly in a model configuration. GGUF models loaded with this backend benefit from ik_llama.cpp's optimized CPU kernels — especially useful for MoE models and large quantized models that would otherwise be GPU-bound.

#### YAML configuration

To use the `ik-llama-cpp` backend, specify it as the backend in the YAML file:

```yaml
name: my-model
backend: ik-llama-cpp
parameters:
  # Relative to the models path
  model: file.gguf
```

The aliases `ik-llama` and `ik_llama` are also accepted.

#### Reference

- [ik_llama.cpp](https://github.com/ikawrakow/ik_llama.cpp)


### turboquant (llama.cpp fork with TurboQuant KV-cache)

[llama-cpp-turboquant](https://github.com/TheTom/llama-cpp-turboquant) is a `llama.cpp` fork that adds the **TurboQuant KV-cache** quantization scheme. It reuses the upstream `llama.cpp` codebase and ships as a drop-in alternative backend inside LocalAI, sharing the same gRPC server sources as the stock `llama-cpp` backend — so any GGUF model that runs on `llama-cpp` also runs on `turboquant`.

You would pick `turboquant` when you want **smaller KV-cache memory pressure** (longer contexts on the same VRAM) or to experiment with the fork's quantized KV representations on top of the standard `cache_type_k` / `cache_type_v` knobs already supported by upstream `llama.cpp`.

#### Features

- Drop-in GGUF compatibility with upstream `llama.cpp`.
- TurboQuant KV-cache quantization (see fork README for the current set of accepted `cache_type_k` / `cache_type_v` values).
- Same feature surface as the `llama-cpp` backend: text generation, embeddings, tool calls, multimodal via mmproj.
- Available on CPU (AVX/AVX2/AVX512/fallback), NVIDIA CUDA 12/13, AMD ROCm/HIP, Intel SYCL f32/f16, Vulkan, and NVIDIA L4T.

#### Setup

`turboquant` ships as a separate container image in the LocalAI backend gallery. Install it like any other backend:

```bash
local-ai backends install turboquant
```

Or pick a specific flavor for your hardware (example tags: `cpu-turboquant`, `cuda12-turboquant`, `cuda13-turboquant`, `rocm-turboquant`, `intel-sycl-f16-turboquant`, `vulkan-turboquant`).

#### YAML configuration

To run a model with `turboquant`, set the backend in your model YAML and optionally pick quantized KV-cache types:

```yaml
name: my-model
backend: turboquant
parameters:
  # Relative to the models path
  model: file.gguf
# Use TurboQuant's own KV-cache quantization schemes. The fork accepts
# the standard llama.cpp types (f16, f32, q8_0, q4_0, q4_1, q5_0, q5_1)
# and adds three TurboQuant-specific ones: turbo2, turbo3, turbo4.
# turbo3 / turbo4 auto-enable flash_attention (required for turbo K/V)
# and offer progressively more aggressive compression.
cache_type_k: turbo3
cache_type_v: turbo3
context_size: 8192
```

The `cache_type_k` / `cache_type_v` fields map to llama.cpp's `-ctk` / `-ctv` flags. The stock `llama-cpp` backend only accepts the standard llama.cpp types — to use `turbo2` / `turbo3` / `turbo4` you need this `turboquant` backend, which is where the fork's TurboQuant code paths actually take effect. Pick `q8_0` here and you're just running stock llama.cpp KV quantization; pick `turbo*` and you're running TurboQuant.

#### Reference

- [llama-cpp-turboquant](https://github.com/TheTom/llama-cpp-turboquant)
- [Tracked branch: `feature/turboquant-kv-cache`](https://github.com/TheTom/llama-cpp-turboquant/tree/feature/turboquant-kv-cache)


### vLLM

[vLLM](https://github.com/vllm-project/vllm) is a fast and easy-to-use library for LLM inference.

LocalAI has a built-in integration with vLLM, and it can be used to run models. You can check out `vllm` performance [here](https://github.com/vllm-project/vllm#performance).

#### Setup

Create a YAML file for the model you want to use with `vllm`.

To setup a model, you need to just specify the model name in the YAML config file:
```yaml
name: vllm
backend: vllm
parameters:
    model: "facebook/opt-125m"

```

The backend will automatically download the required files in order to run the model.


#### Usage

Use the `completions` endpoint by specifying the `vllm` backend:
```
curl http://localhost:8080/v1/completions -H "Content-Type: application/json" -d '{   
   "model": "vllm",
   "prompt": "Hello, my name is",
   "temperature": 0.1, "top_p": 0.1
 }'
```

#### Passing arbitrary vLLM options with `engine_args`

A subset of `AsyncEngineArgs` is exposed as typed YAML fields
(`tensor_parallel_size`, `gpu_memory_utilization`, `quantization`,
`max_model_len`, `dtype`, `trust_remote_code`, `enforce_eager`, …).
Anything else can be passed through the generic `engine_args:` map.
Keys are forwarded verbatim to vLLM's engine; unknown keys fail at load
time with the closest valid name as a hint. Nested maps materialise
into vLLM's nested config dataclasses (`SpeculativeConfig`,
`KVTransferConfig`, `CompilationConfig`, …).

Speculative decoding (DFlash, ngram, eagle, deepseek_mtp, …) is
configured this way:

```yaml
name: qwen3.5-4b-dflash
backend: vllm
parameters:
  model: Qwen/Qwen3.5-4B
context_size: 8192
max_model_len: 8192
trust_remote_code: true
quantization: fp8
template:
  use_tokenizer_template: true
engine_args:
  speculative_config:
    method: dflash
    model: z-lab/Qwen3.5-4B-DFlash
    num_speculative_tokens: 15
```

The shape of `speculative_config` follows vLLM's
[`SpeculativeConfig`](https://docs.vllm.ai/en/latest/api/vllm/config/speculative.html)
— `method` picks the algorithm, the remaining keys are method-specific.
Drafters from [z-lab](https://huggingface.co/z-lab) are paired with
specific target models; pick the one that matches your target. The
drafter loads in its native precision regardless of the target's
`quantization:` setting.

Another example — picking a non-default attention backend (e.g. on
hardware where the default cutlass kernels aren't supported):

```yaml
engine_args:
  attention_backend: TRITON_ATTN
```

#### Multi-node data parallelism

`engine_args.data_parallel_size > 1` combined with the
`local-ai p2p-worker vllm` follower lets a single model span multiple
GPU nodes. See [vLLM Multi-Node (Data-Parallel)]({{% relref
"features/distributed-mode#vllm-multi-node-data-parallel" %}})
for the head/follower configuration and a worked Kimi-K2.6 example.

### SGLang

[SGLang](https://github.com/sgl-project/sglang) is a fast serving
framework for LLMs and VLMs with a focus on prefix caching, speculative
decoding, and multi-modal generation. LocalAI ships a gRPC backend that
wraps SGLang's async `Engine`, including its native function-call and
reasoning parsers.

#### Setup

```yaml
name: sglang
backend: sglang
parameters:
  model: "Qwen/Qwen3-4B"
template:
  use_tokenizer_template: true
```

The backend will pull the model from HuggingFace on first load.

#### Passing arbitrary SGLang options with `engine_args`

The same `engine_args:` map that the vLLM backend accepts is also
honoured by the SGLang backend. Keys are validated against
[`ServerArgs`](https://github.com/sgl-project/sglang/blob/main/python/sglang/srt/server_args.py)
— SGLang's central configuration dataclass — and forwarded verbatim to
`Engine(**kwargs)`. Unknown keys fail at load time with the closest
valid name as a hint. Unlike vLLM, `ServerArgs` is flat: speculative
decoding fields are top-level (`speculative_algorithm`,
`speculative_draft_model_path`, etc.) rather than nested under a
`speculative_config:` dict.

The typed YAML fields shared with vLLM are mapped to their SGLang
equivalents (`gpu_memory_utilization` → `mem_fraction_static`,
`enforce_eager` → `disable_cuda_graph`, `tensor_parallel_size` →
`tp_size`, `max_model_len` → `context_length`). Anything else,
including all speculative-decoding flags, goes under `engine_args:`.

##### Speculative decoding: Gemma 4 with Multi-Token Prediction

Google publishes paired "assistant" drafters for every Gemma 4 size.
The drafters use Multi-Token Prediction (MTP) to propose several
candidate tokens per target step, which SGLang then verifies in
parallel. Flags below are transcribed verbatim from the
[SGLang Gemma 4 cookbook](https://docs.sglang.io/cookbook/autoregressive/Google/Gemma4#speculative-decoding-mtp-server-commands).

For consumer GPUs in the 16–24 GB range, use **E4B** (8 B total /
4 B effective parameters):

```yaml
name: gemma-4-e4b-mtp
backend: sglang
parameters:
  model: google/gemma-4-E4B-it
context_size: 4096
template:
  use_tokenizer_template: true
options:
  - tool_parser:gemma4
  - reasoning_parser:gemma4
engine_args:
  mem_fraction_static: 0.85
  speculative_algorithm: NEXTN
  speculative_draft_model_path: google/gemma-4-E4B-it-assistant
  speculative_num_steps: 5
  speculative_num_draft_tokens: 6
  speculative_eagle_topk: 1
```

For smaller cards (8–12 GB), drop to **E2B** (5 B total / 2 B effective)
by swapping the model paths to `google/gemma-4-E2B-it` and
`google/gemma-4-E2B-it-assistant`; the rest of the flags stay the same.

`NEXTN` is normalised to `EAGLE` inside `ServerArgs.__post_init__`, so
either value works — the cookbook uses `NEXTN`. `mem_fraction_static`
is the share of GPU memory SGLang reserves for the model + KV pool;
0.85 is the cookbook's default and adapts to whatever single GPU the
backend is running on.

The 31 B dense and 26 B-A4B MoE Gemma 4 variants exist in the same
cookbook but require `--tp-size 2`, so they're not in the gallery as
single-GPU recipes.

> **SGLang version requirement.** Gemma 4 support landed in SGLang via
> [PR #21952](https://github.com/sgl-project/sglang/pull/21952). The
> LocalAI sglang backend pins a release that includes it; if you've
> overridden the pin to an older version, this recipe will fail with a
> "model architecture not recognised" error at load time.

##### Other speculative algorithms

`speculative_algorithm:` also accepts `EAGLE`/`EAGLE3` (paired with an
EAGLE-style draft head), `DFLASH` (block-diffusion drafters from
[z-lab](https://huggingface.co/z-lab) for the Qwen3 family), `STANDALONE`
(a smaller draft LLM verifying a larger target), and `NGRAM` (no draft
model — pure prefix-history speculation). See SGLang's
[speculative-decoding docs](https://docs.sglang.io/advanced_features/speculative_decoding.html)
for the full algorithm matrix.

#### Tool calling and reasoning parsers

SGLang's native parsers stream `tool_calls` and `reasoning_content`
inside `ChatDelta` — the LocalAI Python backend wires them up
per-request rather than via `engine_args:`. Pick a parser by name:

```yaml
options:
  - tool_parser:hermes
  - reasoning_parser:deepseek_r1
```

The full list of registered parsers lives in `sglang.srt.function_call`
and `sglang.srt.parser.reasoning_parser`.

### Transformers

[Transformers](https://huggingface.co/docs/transformers/index) is a State-of-the-art Machine Learning library for PyTorch, TensorFlow, and JAX.

LocalAI has a built-in integration with Transformers, and it can be used to run models.

This is an extra backend - in the container images (the `extra` images already contains python dependencies for Transformers) is already available and there is nothing to do for the setup.

#### Setup

Create a YAML file for the model you want to use with `transformers`.

To setup a model, you need to just specify the model name in the YAML config file:
```yaml
name: transformers
backend: transformers
parameters:
    model: "facebook/opt-125m"
type: AutoModelForCausalLM
quantization: bnb_4bit # One of: bnb_8bit, bnb_4bit, xpu_4bit, xpu_8bit (optional)
```

The backend will automatically download the required files in order to run the model.

#### Parameters

##### Type

| Type | Description |
| --- | --- |
| `AutoModelForCausalLM` | `AutoModelForCausalLM` is a model that can be used to generate sequences. Use it for NVIDIA CUDA and Intel GPU with Intel Extensions for Pytorch acceleration |
| `OVModelForCausalLM` | for Intel CPU/GPU/NPU OpenVINO Text Generation models |
| `OVModelForFeatureExtraction` | for Intel CPU/GPU/NPU OpenVINO Embedding acceleration |
| N/A | Defaults to `AutoModel` |

- `OVModelForCausalLM` requires OpenVINO IR [Text Generation](https://huggingface.co/models?library=openvino&pipeline_tag=text-generation) models from Hugging face
- `OVModelForFeatureExtraction` works with any Safetensors Transformer [Feature Extraction](https://huggingface.co/models?pipeline_tag=feature-extraction&library=transformers,safetensors) model from Huggingface (Embedding Model)

Please note that streaming is currently not implemente in `AutoModelForCausalLM` for Intel GPU.
AMD GPU support is not implemented.
Although AMD CPU is not officially supported by OpenVINO there are reports that it works: YMMV.

##### Embeddings
Use `embeddings: true` if the model is an embedding model

##### Inference device selection
Transformer backend tries to automatically select the best device for inference, anyway you can override the decision manually overriding with the `main_gpu` parameter.

| Inference Engine | Applicable Values |
| --- | --- |
| CUDA | `cuda`, `cuda.X` where X is the GPU device like in `nvidia-smi -L` output |
| OpenVINO | Any applicable value from [Inference Modes](https://docs.openvino.ai/2024/openvino-workflow/running-inference/inference-devices-and-modes.html) like `AUTO`,`CPU`,`GPU`,`NPU`,`MULTI`,`HETERO` |

Example for CUDA:
`main_gpu: cuda.0`

Example for OpenVINO:
`main_gpu: AUTO:-CPU`

This parameter applies to both Text Generation and Feature Extraction (i.e. Embeddings) models.

##### Inference Precision
Transformer backend automatically select the fastest applicable inference precision according to the device support.
CUDA backend can manually enable *bfloat16* if your hardware support it with the following parameter:

`f16: true`

##### Quantization

| Quantization | Description |
| --- | --- |
| `bnb_8bit` | 8-bit quantization |
| `bnb_4bit` | 4-bit quantization |
| `xpu_8bit` | 8-bit quantization for Intel XPUs |
| `xpu_4bit` | 4-bit quantization for Intel XPUs |

##### Trust Remote Code
Some models like Microsoft Phi-3 requires external code than what is provided by the transformer library.
By default it is disabled for security.
It can be manually enabled with:
`trust_remote_code: true`

##### Maximum Context Size
Maximum context size in bytes can be specified with the parameter: `context_size`. Do not use values higher than what your model support.

Usage example:
`context_size: 8192`

##### Auto Prompt Template
Usually chat template is defined by the model author in the `tokenizer_config.json` file.
To enable it use the `use_tokenizer_template: true` parameter in the `template` section.

Usage example:
```
template:
  use_tokenizer_template: true
```

##### Custom Stop Words
Stopwords are usually defined in `tokenizer_config.json` file.
They can be overridden with the `stopwords` parameter in case of need like in llama3-Instruct model.

Usage example:
```
stopwords:
- "<|eot_id|>"
- "<|end_of_text|>"
```

#### Usage

Use the `completions` endpoint by specifying the `transformers` model:
```
curl http://localhost:8080/v1/completions -H "Content-Type: application/json" -d '{   
   "model": "transformers",
   "prompt": "Hello, my name is",
   "temperature": 0.1, "top_p": 0.1
 }'
```

#### Examples

##### OpenVINO

A model configuration file for openvion and starling model:

```yaml
name: starling-openvino
backend: transformers
parameters:
  model: fakezeta/Starling-LM-7B-beta-openvino-int8
context_size: 8192
threads: 6
f16: true
type: OVModelForCausalLM
stopwords:
- <|end_of_turn|>
- <|endoftext|>
prompt_cache_path: "cache"
prompt_cache_all: true
template:
  chat_message: |
    {{if eq .RoleName "system"}}{{.Content}}<|end_of_turn|>{{end}}{{if eq .RoleName "assistant"}}<|end_of_turn|>GPT4 Correct Assistant: {{.Content}}<|end_of_turn|>{{end}}{{if eq .RoleName "user"}}GPT4 Correct User: {{.Content}}{{end}}

  chat: |
    {{.Input}}<|end_of_turn|>GPT4 Correct Assistant:

  completion: |
    {{.Input}}
```