--- license: mit library_name: transformers tags: - preserved - repository-exploration - subagent - coder - agentic - qwen3 - 256k - long-context language: - en pipeline_tag: text-generation ---  PRESERVED ORIGINAL // REMOVED BY MICROSOFT FROM HF + GITHUB // MIT microsoft/FastContext ──▶ 404 github.com/microsoft/FastContext ──▶ 404 │ ▼ ┌──────────────────────────┐ │ weights preserved here │ │ bf16 · 8.0 GB · intact │ └──────────────────────────┘ you can't un-open-source FASTCONTEXT-1.0-4B-SFT PRESERVED ORIGINAL WEIGHTS · QWEN3 DENSE 4B · 256K CONTEXT · BF16 · 8.0 GB WEIGHTS BF16 · UNMODIFIED ARCH QWEN3 DENSE · 36L CONTEXT 256K NATIVE LICENSE MIT > Microsoft open-sourced FastContext under MIT, then **deleted it from both HuggingFace and GitHub** about two weeks later (verified: 404 on both, 2026-07-02). MIT means preservation is legal — so here it is, unmodified. **Own your AI: a model on your disk can't be sunset by a quarterly review.** ## 🔍 What it is A **repository-exploration subagent** for coding agents. Invoked on demand by your main agent, it fires **parallel read-only tool calls** (`READ` / `GLOB` / `GREP`) across a repo and returns **only the file paths + line ranges that matter**, as compact context. Your frontier coding agent stops wasting its context window (and your bill) crawling the file tree. Microsoft's (now-deleted) announcement reported **~60% fewer tokens** from the main coding agent and **+5.5% on SWE-bench** — their figures; the source no longer exists to cite. **Architecture**: plain `Qwen3ForCausalLM` dense 4B — 36 layers, 256K native context. No exotic modules; loads with standard `transformers`. ## 🚀 Quick start ```python from transformers import AutoModelForCausalLM, AutoTokenizer m = AutoModelForCausalLM.from_pretrained("KikoCis/FastContext-1.0-4B-SFT", torch_dtype="bfloat16", device_map="auto") tok = AutoTokenizer.from_pretrained("KikoCis/FastContext-1.0-4B-SFT") ``` **Don't want 8 GB?** Grab the **GGUF quants** (1.96–2.5 GB, long-context imatrix, retrieval-validated 30/30 vs this bf16): 👉 [KikoCis/FastContext-1.0-4B-longctx-imatrix-GGUF](https://huggingface.co/KikoCis/FastContext-1.0-4B-longctx-imatrix-GGUF) ## ⚠️ Good to know - It's a **scout, not a solver** — it finds and returns evidence; pair it with a main coding agent that writes the actual fix. - Upstream docs, harness code and issues were deleted along with the repos; usage conventions here come from the announcement and community mirrors. - Weights are **byte-identical** to the (re-uploaded) original — no fine-tuning, no edits. ## 📚 Credit & license Model, weights, training: **© Microsoft** (MIT). This is a preservation mirror sourced via the `ShaunGves/FastContext-1.0-4B-SFT` re-upload after `microsoft/FastContext-1.0-4B-SFT` was removed. Nothing modified. Quantized companion + validation: KikoCis.
