Hissab - Calculator for Artificial and Human Intelligence

Hey Product Hunt, I built Hissab because I kept bouncing between a unit converter, mortgage calculator, epoch converter, spreadsheet, and search box for calculations that I could say in one sentence. Python was too much ceremony for quick math, and asking an LLM directly produced confident numbers that were not always right. Hissab's core is a hand-built lexer, parser, and typed-token evaluator. It carries units and types through the calculation, so incompatible values fail instead of becoming a silent wrong answer. The product stance is strictness: a calculator should only evaluate what it can prove it understood. The AI workflow keeps that split clean. The model translates messy language into a visible Hissab expression, then the deterministic engine computes the result. The same expression works in the web app, Chrome extension, CLI, npm library, hosted MCP server, and agent skills. This is the open-source relaunch. The earlier version was closed-source and did not include the CLI, library, skills, or MCP server. AI features are bring-your-own-key for OpenAI, Anthropic, Gemini, DeepSeek, or custom OpenAI-compatible endpoints. Honest limits: the local engine does not fetch live FX rates, equation solving is not built yet, and Hissab is not trying to replace Python for datasets, ML, or custom programs. It is built for exact, readable calculation work that should not be guessed by a model. I would value feedback on the strictness tradeoff, the developer calculator surface, and the agent/MCP workflow.