OpenAI API
The most third-party tooling, docs, and examples of any AI provider, so it's the safest bet if you want your feature to just work with common libraries.
What is the OpenAI API?
The OpenAI API provides programmatic access to OpenAI's models for text generation, structured outputs, function/tool calling, embeddings, image generation, and more. It's less notable for any single feature than for how much third-party tooling, SDKs, and community knowledge already assume it as the default: most AI libraries, tutorials, and example repos are written against it first, with other providers added as an afterthought or an alternate config.
Key features
- Broad model lineup covering different price/capability tradeoffs, from lightweight fast models to higher-capability ones
- Function/tool calling and structured output support for building agents and reliable JSON responses
- Embeddings and vector-adjacent endpoints for search and retrieval use cases
- The largest surface of third-party library support, framework integrations, and community examples of any AI provider
- Usage-based API pricing with no infrastructure to manage
Who it's for
Builders who want the path of least resistance: whatever library, framework, or tutorial they're following almost certainly targets this API first. Teams with specific requirements around a different model's reasoning style, context window, or pricing profile should compare directly rather than defaulting here purely out of habit.
Pricing
Usage-based, priced per token and varying by model. Check the site for current rates, since pricing changes as new models ship.