Luau Qwen3 4B FIM v0.1

A specialized fine tune of Qwen/Qwen3-4B-Instruct-2507 trained specifically for FIM Luau code based on "Efficient Training of Language Models to Fill in the Middle" by Mohammad Bavarian et al., 2022. Instead of being a chatbot, it performs Luau autocomplete.

Expected format

<|repo_name|> and <|file_sep|> are technically optional, but you will get better responses when they are included.

If using a chat API:

[
   { "role": "system", "content": "You are a code completion assistant." },
   { "role": "user", "content": f"<|repo_name|>{reponame}<|file_sep|>{filename}<|fim_suffix|>{suffix}<|fim_prefix|>{prefix}<|fim_middle|>" }
]

If using a completions API, you'll need to essentially bake the chat template in:

prompt = f"<|im_start|>system\nYou are a code completion assistant.<|im_end|>\n<|im_start|>user\n<|repo_name|>{reponame}<|file_sep|>{filename}<|fim_suffix|>{suffix}<|fim_prefix|>{prefix}<|fim_middle|><|im_end|>\n<|im_start|>assistant\n"

Here is an example config.yaml for using this with Continue.dev for autocomplete in VSCode backed by LM Studio:

name: Local Autocomplete
version: 1.0.0
schema: v1
models:
  - name: Luau Qwen3 4B FIM v0.1
    provider: lmstudio
    apiBase: http://localhost:1234/v1
    model: luau-qwen3-4b-fim-v0.1
    roles:
      - autocomplete
    defaultCompletionOptions:
      stop: [
        "<|im_end|>",
        "</s>",
        "<|repo_name|>",
        "<|file_sep|>",
        "```"
      ]
    promptTemplates:
      autocomplete: "<|im_start|>system\nYou are a code completion assistant.<|im_end|>\n<|im_start|>user\n<|repo_name|>{{{reponame}}}<|file_sep|>{{{filename}}}<|fim_suffix|>{{{suffix}}}<|fim_prefix|>{{{prefix}}}<|fim_middle|><|im_end|>\n<|im_start|>assistant\n"

Model Information

Developer: Zack Williams (boatbomber)
Sponsor: Torpedo Software LLC
Base Model: Qwen/Qwen3-4B-Instruct-2507
Training Method: SFT (Supervised Finetuning)

Training Methodology

Dataset

Source: TorpedoSoftware/the-luau-stack

500,000 FIM-formatted Luau code snippets
- Completion to end of line, end of block, next few lines, etc
- Varied between Suffix Prefix Middle order and Prefix Suffix Middle order