Fara1.5-4B-GGUF

Fara1.5-4B — GGUF (llama.cpp)

llama.cpp GGUF conversion of microsoft/Fara1.5-4B, Microsoft AI Frontiers' agentic Computer-Use Agent (CUA) for web browsers (Qwen3.5-VL arch, Qwen3_5ForConditionalGeneration). This repo only re-packages Microsoft's model for on-device inference — all capabilities and credit belong to Microsoft AI Frontiers. Original model, full system prompt, and MagenticLite agent scaffold: https://huggingface.co/microsoft/Fara1.5-4B and https://github.com/microsoft/fara.

Files

A VLM needs both a text GGUF and the mmproj. llama.cpp maps the vision tower to PROJECTOR_TYPE_QWEN3VL and the text model to LLM_ARCH_QWEN3VL.

Conversion

Produced with a qwen3_5-aware llama.cpp convert_hf_to_gguf.py:

python convert_hf_to_gguf.py microsoft/Fara1.5-4B --outfile Fara1.5-4B-f16.gguf --outtype f16
python convert_hf_to_gguf.py microsoft/Fara1.5-4B --mmproj --outfile mmproj-Fara1.5-4B-f16.gguf
llama-quantize Fara1.5-4B-f16.gguf Fara1.5-4B-Q4_K_M.gguf Q4_K_M

Usage

llama-mtmd-cli -m Fara1.5-4B-Q4_K_M.gguf --mmproj mmproj-Fara1.5-4B-f16.gguf \
  --image screenshot.png -p "<FARA_SYSTEM_PROMPT> ... your task"

Fara is a web-browser agent. Use Microsoft's contract (see the base model):

• Provide the full system prompt including the computer_use tool schema inside <tools></tools>.
• The model emits <tool_call>{"name": "computer_use", "arguments": {...}}</tool_call>.
• Coordinates are returned in a fixed 1000×1000 space; scale to your viewport (e.g. x*1.44, y*0.9 for a 1440×900 window). 1440×900 is the recommended capture size.

Validation

Verified running on Apple silicon through llama.cpp (CPU and Metal GPU). On real 1440×900 browser screenshots with Fara's exact CUA prompt, the Q4_K_M produced valid left_click tool-calls with correct coordinate grounding (matching an independent community Q4_K_M byte-for-byte on shared tasks, and matching the MLX 4-bit build).

License

MIT, inherited from microsoft/Fara1.5-4B. Review Microsoft's model card for intended use, limitations, and responsible-AI guidance (Fara pauses at safety-critical points; keep a human in the loop for irreversible actions).