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Mini-SGLang

Mini-SGLang is a compact implementation of SGLang, designed to demystify the complexities of modern LLM serving systems. With a compact codebase of ~5,000 lines of Python, it serves as both a capable inference engine and a transparent reference for researchers and developers.
Platform Support: Mini-SGLang currently supports Linux only (x86_64 and aarch64). Windows and macOS are not supported due to dependencies on Linux-specific CUDA kernels (sgl-kernel, flashinfer). We recommend using WSL2 on Windows or Docker for cross-platform compatibility.

Key Features

High Performance

Achieves state-of-the-art throughput and latency with advanced optimizations including FlashAttention and FlashInfer kernels.

Lightweight & Readable

A clean, modular, and fully type-annotated codebase that is easy to understand and modify - just ~5,000 lines of Python.

Radix Cache

Reuses KV cache for shared prefixes across requests, reducing redundant computation and improving efficiency.

Chunked Prefill

Reduces peak memory usage for long-context serving by splitting prompts into smaller chunks during the prefill phase.

Overlap Scheduling

Hides CPU scheduling overhead with GPU computation, improving overall system throughput.

Tensor Parallelism

Scales inference across multiple GPUs seamlessly with built-in support for distributed serving.

Advanced Optimizations

Mini-SGLang integrates cutting-edge techniques to maximize performance:
  • Radix Cache: Reuses KV cache for shared prefixes across requests
  • Chunked Prefill: Reduces peak memory usage for long-context serving
  • Overlap Scheduling: Hides CPU scheduling overhead with GPU computation
  • Tensor Parallelism: Scales inference across multiple GPUs
  • Optimized Kernels: Integrates FlashAttention and FlashInfer for maximum efficiency
  • CUDA Graph: Minimizes CPU launch overhead during decoding

Supported Models

Mini-SGLang currently supports the following model architectures:

Getting Started

Quick Start

Get up and running with Mini-SGLang in under 5 minutes

Installation

Detailed installation instructions for all platforms and methods

What Makes Mini-SGLang Special?

Mini-SGLang bridges the gap between performance and transparency. While most LLM serving frameworks are either high-performance but complex, or simple but slow, Mini-SGLang delivers both:
  • Educational: The compact, well-documented codebase makes it an ideal learning resource for understanding modern LLM serving techniques
  • Production-Ready: Despite its simplicity, it delivers competitive performance with state-of-the-art optimizations
  • Modular Design: Clean abstractions make it easy to experiment with new ideas and customize for specific use cases

System Architecture

Mini-SGLang is designed as a distributed system with several independent processes working together:
  • API Server: Provides an OpenAI-compatible API to receive prompts and return generated text
  • Tokenizer Worker: Converts input text into tokens that the model can understand
  • Detokenizer Worker: Converts model output tokens back into human-readable text
  • Scheduler Worker: Manages computation and resource allocation for each GPU
Components communicate using ZeroMQ (ZMQ) for control messages and NCCL for heavy tensor data exchange between GPUs.
Want to dive deeper? Check out the system architecture documentation to understand the complete data flow and code organization.

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