Freeplay

Freeplay is an end to end platform for testing, evaluating, and monitoring LLM powered products. Its central idea is that building with language models is a team sport, so it brings prompt management, evaluations, experiments, and production observability into one surface where product managers, engineers, QA, and domain experts review the same traces instead of trading spreadsheets. The company was founded in 2022 by Ian Cairns and Eric Ryan, who previously led Twitter's developer platform and first worked together at Gnip, and it is aimed at the cross functional teams taking generative AI features from prototype to production.

Freeplay can act as the source of truth for prompt templates, which an application fetches at runtime or build time, so non engineers can iterate on prompts and swap models without a code change. A prompt editor lets teams test combinations of prompts, models, and parameters against real data, then launch batch tests from the browser. Because Freeplay treats every prompt and model configuration as an experiment, teams can compare versions side by side and, once satisfied, deploy a change straight from the results page much like a feature flag.

On the evaluation side, Freeplay runs offline and online evals using model graded judges, code based scorers, and auto categorization, and its signature workflow aligns those automated judges with human labels so the scores reflect a team's actual judgment. Production observability lets teams search and filter across millions of completions down to individual traces, inspecting prompt versions, input variables, RAG context, cost, and latency. Human in the loop review and labeling queues turn production issues into curated datasets for testing and fine tuning, closing the loop between what ships and what gets improved.

Freeplay is designed to stay out of the runtime hot path: it separates prompt management, LLM calls, and observability, and ships SDKs for Python, Node and TypeScript, and the JVM so developers keep full control of their code and model choice. It supports multiple providers including OpenAI, Anthropic, Google Vertex, AWS Bedrock, and Groq. The product is generally available with a free tier to start, and self hosting and enterprise options on request. Freeplay has raised about $8.9M, most recently a round led by Renegade Partners in 2025, and counts teams like Postscript and Help Scout among its users.