OpenAI Guardrails
OpenAI's official Python/TS library for adding guardrails to Responses API and Assistants API applications. Ships moderation, jailbreak detection, hallucination checks, and PII filters as composable guardrails.
OpenAI API
API access to GPT-5, GPT-5.5, o3/o4 reasoning models, and the Responses API; plus embeddings, image, audio, and Realtime endpoints. The most widely deployed LLM API in production.