Which Qwen models can do FIM (Fill in the middle) for autocompletion?

Posted by 0xbeda@reddit | LocalLLaMA | View on Reddit | 9 comments

I cannot find a definive answer. I think the following should be able to do FIM:

Qwen 2.5 coder
Qwen 3 coder
Qwen 3 2507 refresh instruct models
Qwen 3.5 instruct (intuition, please check)
Qwen 3.6 instruct (intuition, please check)

What I verified:

Qwen3-32B: no
Qwen3-4B-Instruct-2507: yes

Tested with unsloth GGUFs in llama.cpp. All expose identical FIM PRE/SUF/MID metadata (shared tokenizer, IDs 151659–151664), so metadata proves nothing.

Is there any official statement?

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Impossible_Art9151@reddit

we have FIM working here with qwen3.5-4b (replacing good old qwen2.5-coder). Havn't configured it by myself but can confirm it works ....

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Which ide and extension? I have the backend working and continue.dev gets autocomplete responses from vllm running Qwen3.6-35B-A3B but the extension doesn't show the suggestion.
u/DinoAmino Qwen3.5/3.6 seems to understand the fim tokens just fine, but it needs the "You are a code completion assistant" system prompt. I'm hacking the prompt into the template, since continue.dev doesn't support sending a system prompt to an autocomplete model

    autocompleteOptions:
      modelTimeout: 2000
      maxPromptTokens: 7000
      debounceDelay: 300
      template: |
        You are a code completion assistant.
        <|fim_prefix|>{{{prefix}}}<|fim_suffix|>{{{suffix}}}<|fim_middle|><|im_end|>

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