54 lines
2.7 KiB
Markdown
54 lines
2.7 KiB
Markdown
# Tabby Model Specification (Unstable)
|
|
|
|
Tabby organizes the model within a directory. This document provides an explanation of the necessary contents for supporting model serving. An example model directory can be found at https://huggingface.co/TabbyML/StarCoder-1B
|
|
|
|
The minimal Tabby model directory should include the following contents:
|
|
|
|
```
|
|
ctranslate2/
|
|
ggml/
|
|
tabby.json
|
|
tokenizer.json
|
|
```
|
|
|
|
### tabby.json
|
|
|
|
This file provides meta information about the model. An example file appears as follows:
|
|
|
|
```json
|
|
{
|
|
"auto_model": "AutoModelForCausalLM",
|
|
"prompt_template": "<PRE>{prefix}<SUF>{suffix}<MID>",
|
|
"chat_template": "<s>{% for message in messages %}{% if message['role'] == 'user' %}{{ '[INST] ' + message['content'] + ' [/INST]' }}{% elif message['role'] == 'assistant' %}{{ message['content'] + '</s> ' }}{% endif %}{% endfor %}",
|
|
}
|
|
```
|
|
|
|
The **auto_model** field can have one of the following values:
|
|
- `AutoModelForCausalLM`: This represents a decoder-only style language model, such as GPT or Llama.
|
|
- `AutoModelForSeq2SeqLM`: This represents an encoder-decoder style language model, like T5.
|
|
|
|
The **prompt_template** field is optional. When present, it is assumed that the model supports [FIM inference](https://arxiv.org/abs/2207.14255).
|
|
|
|
One example for the **prompt_template** is `<PRE>{prefix}<SUF>{suffix}<MID>`. In this format, `{prefix}` and `{suffix}` will be replaced with their corresponding values, and the entire prompt will be fed into the LLM.
|
|
|
|
The **chat_template** field is optional. When it is present, it is assumed that the model supports an instruct/chat-style interaction, and can be passed to `--chat-model`.
|
|
|
|
### tokenizer.json
|
|
This is the standard fast tokenizer file created using [Hugging Face Tokenizers](https://github.com/huggingface/tokenizers). Most Hugging Face models already come with it in repository.
|
|
|
|
### ctranslate2/
|
|
This directory contains binary files used by the [ctranslate2](https://github.com/OpenNMT/CTranslate2) inference engine. Tabby utilizes ctranslate2 for inference on both `cpu` and `cuda` devices.
|
|
|
|
With the [python package](https://pypi.org/project/ctranslate2) installed, you can acquire this directory by executing the following command in the HF model directory:
|
|
|
|
```bash
|
|
ct2-transformers-converter --model ./ --output_dir ctranslate2 --quantization=float16
|
|
```
|
|
|
|
*Note that the model itself must be compatible with ctranslate2.*
|
|
|
|
### ggml/
|
|
This directory contains binary files used by the [llama.cpp](https://github.com/ggerganov/llama.cpp) inference engine. Tabby utilizes ggml for inference on the `metal` device.
|
|
|
|
Currently, only `q8_0.gguf` in this directory is in use. You can refer to the instructions in llama.cpp to learn how to acquire it.
|