About Harfi

Harfi is an innovative game designed to enhance your understanding and control of Artificial Intelligence. It challenges you to write precise instructions for an AI, rather than the answers themselves. Each trial presents a specific set of rules that the AI's output must precisely meet, verified by a parser, not subjective opinion.

How it Works

The Spec: Each trial provides a clear specification for the AI's output, including constraints like exact bullet counts, word limits, and forbidden words or letters.

Your Prompt: You craft an instruction, limited to 120 words, to guide the AI. Shorter prompts score better.

The Parser: Automated code checks the AI's response against all rules. It counts bullets, words, parses data formats like JSON, and scans for banned elements, indicating exactly which rule was broken.

Key Features

Deterministic Scoring: All trials are scored by code, ensuring consistent and objective results.

Five Sets of Trials: Explore challenges focused on format control (bullets, word caps), schema adherence (JSON, CSV, YAML), lexical constraints (banned words, acrostics), data transformation, and output reliability.

Medals and Scoring: Earn medals for clearing trials at all, beating par, achieving it on the first stroke, or using a minimalist prompt (under 25 words).

Free Access: Set 1, featuring eight trials, is available for free forever, requiring no card.

Harfi Plus: Upgrade for access to all five sets, forty trials, and all 160 medals.

AI Models: Play against Claude Haiku 4.5, with a second model used for reliability testing.

Harfi is ideal for anyone looking to improve their AI prompting skills, especially in areas requiring machine-readable output and precise data control, making it valuable for professional AI use cases.