LiteLLM
OSS proxy that normalizes 100+ LLMs to the OpenAI format. Add routing, fallbacks, caching, and cost tracking in one layer.
LLM Guard
MIT-licensed Python toolkit for LLM input/output filtering — prompt-injection detection, PII redaction, toxicity, anonymisation, bias, and more. Top OSS choice for self-hosted runtime guardrails in 2026.