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AI · January 28, 2025

Experiment ▴ LLM UI for developers with tool use visualization

Hey HN! I built Experiment to solve a common frustration in LLM development: the lack of proper tools for prompt engineering experimentation. Here's what makes it different: Key Features: - Load and edit chat completion logs from CSV files - Fork and modify specific conversation entries - Run inference via Anthropic, Mistral, and OpenAI - Define custom tools using JSONSchema format - Visual tool usage analysis with collapsible, sorted key-value pairs - Full mobile support and available as installable PWA Technical Highlights: - Built with React using custom isomorphic architecture -…

Experiment ▴ LLM UI for developers with tool use visualization launched on January 28, 2025 with 8 votes, #2,695 of 6,142 launches that month and more than 75% of that year's launches. The site was still online in September 2026, 1 year on.

What it does

🔬 Experiment is an experiment is an experiment is an experiment is an experiment is an e̴x̷p̶e̶r̶i̶m̸e̸n̸t̴ ̷i̵s̴ ̷a̵n̷ è̷̜x̴̝͝p̵̨̐e̴̯̐r̴͔̍ì̸̻m̴̛͎e̵̥̔n̶̠̎t̷̠͝ ̶̼̳̕ǐ̷̞͍͂s̷͍̈́ ̶̫̀a̵̠͌n̵̲͊ ̶̣̼̆ḛ̸̀x̵̰͋p̵͉̺̎e̶̛͈̮ř̸̜̜̅ì̵̜̠͗ṃ̴̼͆ė̴̮n̶̪̈́t̸̢͖͋͂ - experimental-setup/Experiment

Experiment is an experimental chat interface for Large Language Models (LLMs) with function calling visualization support. Experiment is available in binary and non-binary editions. Binary edition requires no dependencies and includes additional features like 1Password integration for secure token storage. Try the web version instantly at actualwitch.github.io/experiment chmod +x ./experiment- * macOS users also need to remove quarantine: xattr -d com.apple.quarantine ./experiment- * Tool Debugging Experiment provides comprehensive visualization for LLM tool use. Add tools by pasting a JSON schema into chat in OpenAI and Anthropic formats. The schema will be visualized with properties…from github.com

In the maker’s words, at launch

Hey HN! I built Experiment to solve a common frustration in LLM development: the lack of proper tools for prompt engineering experimentation. Here's what makes it different: Key Features: - Load and edit chat completion logs from CSV files - Fork and modify specific conversation entries - Run inference via Anthropic…

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