Electrical / runnable MCP tool
Run the Box Fill Calculator in your AI assistant
Through the free Intry MCP server, Claude, ChatGPT, or Cursor runs this exact calculator and hands back a verdict and the cited source, not a guess. Tool name: box_fill.
Ask your assistant
The one rule that makes it reliable: name Intry in your question. That is what tells Claude to run the box_fill tool and answer with the real number, the verdict, and the citation. Leave Intry out and Claude may just guess from memory, which is exactly what you are trying to avoid. Type something like:
Inputs
| Field | Required | What it is |
|---|---|---|
| boxType | optional | Standard box type key (e.g. '4x1-1/2 square'), or omit and pass customVolume. |
| customVolume | optional | Box volume in cubic inches (overrides boxType). |
| conductors | yes | Insulated conductors entering the box. |
| deviceYokes | optional | Number of devices (switch/receptacle yokes). Default 0. |
| largestDeviceConductor | optional | Largest conductor on a device. Default largest present. |
| internalClamps | optional | Internal cable clamps present? Default false. |
| largestClampConductor | optional | Largest conductor for the clamp allowance. |
| egcCount | optional | Number of equipment grounds. Default 0. |
| largestEgc | optional | Largest EGC size. |
| terminalBlocks | optional | Number of internal terminal blocks. Default 0. |
| luminaireStud | optional | Fixture stud present? Default false. |
| hickey | optional | Hickey present? Default false. |
Add Intry to Claude
One paste and Claude can run this tool and every other Intry calculator, right from your phone.
- Claude opens with the Intry connector already filled in. Review it and click Add.
- (If a field is blank, paste the link below into the URL field.)
- In any chat, tap + then Connectors and switch Intry on. Then name Intry in your question (“use Intry to…”) so Claude runs the tool instead of guessing.
https://www.intrysys.com/api/mcpNo login, no API key, and it works on every Claude plan, right from your phone.
Using ChatGPT, Cursor, or a dev tool? See the developer setup on the main page. The endpoint is https://www.intrysys.com/api/mcp.
Every answer comes with the cited NEC section, so you can check it or show an inspector. The numbers come from the same calculator we run on intrysys.com, and we re-check every one automatically before anything goes live, so the number Claude hands you matches the code.