Together AI
Also known as: Together, TogetherAI, Together.ai
Together AI sits in the space between raw GPU clouds and consumer AI APIs. Like Groq, it gives you an OpenAI-compatible API endpoint for open-weight models so you can swap it in with minimal code changes. Unlike Groq, it supports a much wider catalog (200+ models), offers fine-tuning and training jobs alongside inference, and provides dedicated endpoints for teams that need guaranteed capacity rather than shared serverless pools.
The OpenAI-compatible API is a key practical detail: most AI SDKs (LangChain, LlamaIndex, the OpenAI Python client itself) let you point at a custom base URL, so switching from OpenAI to Together AI for cost or model-choice reasons is often a one-line change. Together AI benchmarks competitively on price-per-token for open-weight models relative to OpenAI equivalent quality tiers.
For builders building on open-weight models at scale, Together AI is frequently mentioned alongside Fireworks AI, Replicate, and Baseten as the mature serverless inference providers. The ability to do fine-tuning and then immediately serve the fine-tuned model through the same API is a workflow advantage for teams iterating on specialized models.