What problem does it solve?
SGLang solves slow and inconsistent LLM serving when you need structured outputs (like JSON/regex/grammar) and repeated prompt prefixes across many requests, by reusing cached computation through RadixAttention.
Core Features & Use Cases
- Fast structured generation: Produce valid JSON via constrained decoding, including regex constraints and grammar-based generation.
- RadixAttention prefix caching: Automatically caches and reuses shared prompt prefixes (e.g., system prompts, few-shot examples, tool definitions) to reduce repeated KV computation.
- Production serving + agent workflows: Run an OpenAI-compatible inference server and support tool/function calling patterns for agentic applications where prompts are largely repeated but queries vary.
- Use Case: Build an agent that repeatedly uses the same system prompt and tool schema while handling many user queries; RadixAttention reuses the shared prefix so each new request computes only the new suffix.
Quick Start
Use the sglang skill to launch a local OpenAI-compatible server and generate constrained JSON answers with RadixAttention enabled.