The CalcTree LLM Skill lets any AI assistant discover, execute, and build CalcTree calculation pages. It works with Claude, ChatGPT, Gemini, Cursor, or any LLM that supports skills or tool use.
Your AI gets access to a deterministic calculation engine with real physical units. It does the reasoning. CalcTree does the maths.
Download the skill · Setup docs
Build calculations from a prompt
Describe what you want computed in plain English and the AI builds a live CalcTree page with inputs, formulas, unit conversions, and pass/fail checks.
In this example, Claude builds a wind load calculator from a single prompt. It sets up the inputs, writes the formulas with proper unit conversions, and adds a traffic light that checks the force against a 5 kN limit. Bump the wind speed from 30 to 40 m/s and the check flips from PASS to FAIL.
Use verified pages as deterministic tools
Instead of trusting an LLM to do the maths, it calls a calculation page anyone on your team can read and verify. Your verified CalcTree pages become deterministic tools for any AI.
Here, Claude designs a simply supported steel beam. It calculates the load itself, calls our beam calculator with custom inputs, reads back the bending moment and deflection, and checks whether the section is adequate. The numbers come from CalcTree's calculation engine, not the LLM.
Export PDF reports from your LLM
The skill also lets your AI export any CalcTree page to PDF, right from the conversation. Build a calculation, verify the results, and get a print-ready engineering report without leaving your LLM.
One prompt, and your AI generates a formatted PDF with a title page, table of contents, and math notation.
How to set it up
You need an API key and the skill file. Generate a key in your workspace settings, download the skill from GitHub, and follow the setup steps for your AI tool in the docs.
Claude users: upload the zip under Settings, Features, Skills and enable network access. ChatGPT and Gemini users: attach the skill document to your conversation. Cursor and Windsurf users: point at the AGENTS.md file in the calctree-skills repo.
