{"id":105027,"title":"Freesolo: Post-Training Built for your Agent","tagline":"Small models, frontier performance","body":"Not every AI interaction is best served with a large frontier model. There is a long tail of trillion-token use cases, from tagging to search, best served by a sub-10B-parameter model that runs in milliseconds and costs many orders of magnitude less than the frontier. However, engineers historically had to choose between model size and quality; as models got smaller, performance, adherence, and recall dropped linearly. Post-training on production data closes that gap. We built Freesolo Flash to make training loops like SFT and RL easy and end-to-end completable through your coding agent.\n\nWe accomplish this in a few different ways\n\n* Upfront pricing: instead of billing by GPU hours or tokens spent while training, we quote the cost of the entire run upfront, so your agent can accurately tweak the dataset, model size, and algorithms it uses while staying in your budget before it starts the run.\n* Our GPU infrastructure is optimized to make your specific run as in-expensive and fast as possible. This optimization means training with flash is 8x less expensive for SFT and 5.5x less expensive for GRPO (RL) when compared to Tinker.\n\nFlash is built out of our own frustrations with current managed post-training solutions, especially for SLMs. We believe that unlocking frontier capability for a narrow task into a small model will prove to be the best improvement for all agentic product UX. Flash is our first step towards solving this. Just grab a Freesolo API Key, point your agent at the training package, and watch it push your lightweight model beyond the frontier.\n\nFlash is publicly available today at  \u003chttps://freesolo.co\u003e[ ](https://freesolo.co/). Train on!","slug":"RJz-freesolo-post-training-built-for-your-agent","created_at":"2026-07-13T19:38:20.322Z","updated_at":"2026-07-22T13:24:34.397Z","total_vote_count":3,"url":"https://www.ycombinator.com/launches/RJz-freesolo-post-training-built-for-your-agent","share_image_url":"//bookface-static.ycombinator.com/assets/ycdc/yc-og-image-c440a0ad1dacfb86eeeb343717479cc54d256614449b4ef719977a0a451f8bc8.png","company":{"id":30462,"name":"Freesolo","slug":"freesolo","url":"https://freesolo.co","logo":"https://bookface-images.s3.amazonaws.com/small_logos/45d118ce06f810c00f7b1f3105cf4f7906bd0d55.png","batch":"Spring 2025","industry":"B2B","tags":["Reinforcement Learning","B2B","AI"],"search_path":"https://bookface.ycombinator.com/company/30462"}}