Quick answer: GPT-4o, o1, embeddings, vision, voice — the broadest model API.
OpenAI API is a RESTful interface that provides programmatic access to OpenAI's frontier AI models, including GPT-4o, o1, and specialized capabilities like embeddings, vision, and voice processing. Built by OpenAI, it falls under the LLM-api category and operates on a pay-per-token pricing model, making it accessible for applications of any scale—from prototypes to production systems serving millions of users.
The API abstracts away the complexity of running large language models, allowing developers to integrate cutting-edge AI capabilities into applications without managing infrastructure. Whether you're building chatbots, content generation systems, code analysis tools, or multimodal applications that process text, images, and audio, the OpenAI API provides a unified platform with consistent model quality and reliability.