naklecha/simple-llm — explained in plain English
Analysis updated 2026-08-10 · repo last pushed 2026-01-09
Trace the full lifecycle of an AI inference request to understand how large language model serving works.
Modify the compact codebase to test novel approaches for speeding up AI processing.
Run the gpt-oss-120b model on an H100 GPU with performance matching production engines like vLLM.
Study modern inference techniques like continuous batching and CUDA graphs in readable code.
| naklecha/simple-llm | kasothaphie/genrecon | ensignkazekage/prodigy-hacks | |
|---|---|---|---|
| Stars | 478 | 478 | 474 |
| Language | Python | Python | Python |
| Last pushed | 2026-01-09 | — | — |
| Maintenance | Quiet | — | — |
| Setup difficulty | hard | hard | easy |
| Complexity | 5/5 | 5/5 | 2/5 |
| Audience | researcher | researcher | general |
Figures from each repo's GitHub metadata at analysis time.
Requires an NVIDIA H100 GPU and the specific gpt-oss-120b model, with no CPU fallback or alternative hardware support.
SimpleLLM is a from-scratch engine for running large language models, built in under 1,000 lines of Python. Instead of relying on heavy existing frameworks, it provides a compact, readable starting point for running AI models on high-end NVIDIA hardware. Right now, it specifically supports running OpenAI's gpt-oss-120b model on a single NVIDIA H100 GPU. Under the hood, it implements modern performance techniques like continuous batching (where new requests join the active processing group instead of waiting in line), CUDA graphs, and specialized math operations that squeeze maximum speed out of the hardware. You interact with it by loading a model and submitting prompts, and the engine handles the rest. It processes everything in a background loop so the GPU never sits idle waiting for the next task, and its performance is competitive with major production engines like vLLM at both single-user and 64-user batch sizes. This project is designed for researchers, students, and research labs who want to understand or experiment with how AI inference actually works. A student could use it to trace the entire lifecycle of an AI request from start to finish without getting lost in layers of abstraction. A researcher testing a novel way to speed up AI processing could modify this codebase directly, rather than trying to strip down a massive production framework to understand it. What makes this notable is the tradeoff: it currently only supports one specific model on one specific GPU. The author deliberately chose a complex starting point to prove that building a modern, high-performance inference engine from scratch is viable. The project includes specialized community-contributed processing kernels and plans to add support for running across multiple GPUs and supporting other model architectures in the future.
A lightweight engine for running large language models from scratch in under 1,000 lines of Python, designed to be readable and educational while delivering production-level performance on NVIDIA hardware.
Mainly Python. The stack also includes Python, CUDA, NVIDIA H100.
Quiet — no commits in 6-12 months (last push 2026-01-09).
No license information is provided in the README, so usage rights are unclear.
Setup difficulty is rated hard, with roughly 1h+ to a first successful run.
Mainly researcher.
This repo across BitVibe Labs
Don't trust strangers blindly. Verify against the repo.