A year ago, OpenAI's GPT-3 was the predominant large language model (LLM), but now there is a variety of models available, including many open-source options that have significantly improved in performance. In response to growing interest in these models, Fireworks AI has partnered with LangSmith to integrate their models into the LangSmith playground, allowing users to access them for free without needing an API key, provided they are signed into the platform. Fireworks AI offers a platform for developers to run, fine-tune, and share LLMs, optimizing for latency, throughput, and cost efficiency, with claims of up to 120 times cost reduction. This integration makes it easier for users to experiment with and optimize prompts using high-performing open-source and fine-tuned models, such as Llama 2 70B, enhancing productivity in developing LLM workflows. Users can easily switch between model providers in the LangSmith Playground and test different prompts and models without any coding, thereby streamlining the otherwise iterative and time-consuming process of prompt optimization.