Flow Pack

Free tools a UK plumber's or heating engineer's AI assistant uses on the job: water and gas pipe sizing, room by room heat loss with boiler, heat pump and radiator sizes, notifiable work rules, gas safety record checks and emergency triage.

Endpoint: https://flow-pack.nerolabs.workers.dev/mcp (MCP, Streamable HTTP) Sign-in: None. No account, no key and no sign-in: add the address and use it. How to connect: https://flow-pack.nerolabs.workers.dev/docs Privacy: https://flow-pack.nerolabs.workers.dev/privacy Support: founder@neroengine.com

Tools

Tool	What it does
list_capabilities	What Flow Pack can do. Lists Flow Pack's tools, what it covers (nations, pipe materials, gases, record types, emergency situations) and what it deliberately does not do.
size_pipe	Water or gas pipe size, velocity and pressure loss. Sizes a hot or cold water pipe, or a low-pressure gas pipe, and shows the working.
size_heat_source	Room by room heat loss, boiler and heat pump size. Works out the heat loss of each room (fabric U x A x delta T plus ventilation 0.33 x air changes x volume x delta T) and the total, then sizes a combi, system or regular boiler, or a heat pump, to the nearest common size.
size_radiators	Radiator size per room, including at heat pump temperatures. For each room's heat loss, works out the rated (delta T 50) radiator output needed at the system's flow and return temperatures, using output = rated x (mean water to air difference / 50) ^ 1.3.
check_notifiable_work	Is this work notifiable, and who can do it?. For plumbing and heating jobs in England or Wales: does it need a Gas Safe registered engineer, an unvented (G3) qualified installer, building regulations notification (Approved Documents G, J, L and others) and a water company notice...
check_gas_record	Check a gas safety record or commissioning record before issuing it. Checks a filled landlord gas safety record (CP12) or a boiler commissioning record and lists errors and warnings: missing required fields, failed tightness, flue, ventilation or safety device checks, CO/CO2 ratio over the limits, gas rate...
emergency_triage	Emergency triage for leaks, bursts, no heat, gas smell or CO alarm. For a homeowner reporting a problem: the safe first steps to do now, what not to do, who to call first (the gas emergency service 0800 111 999 for a gas smell or CO alarm), whether it is a real emergency, and an urgency value of routine,...
trade_profile	Check the plumber or heating engineer's business details. Checks the business's own details (Nero Trade Profile v1: trading name, Companies House number, registration scheme and number, postcode, contact) and returns them cleaned, with a stable nero_trade_ref computed from the scheme...

Every tool carries a plain title and the read-only, destructive and open-world hints, so your AI app can ask before anything that changes data.

Connect

• Claude (web or desktop): Settings, Connectors, Add custom connector, paste the endpoint.
• ChatGPT: Settings, Apps and connectors, Advanced settings, switch on Developer mode, then Create, paste the endpoint, No authentication.
• Claude Code: claude mcp add --transport http flow-pack https://flow-pack.nerolabs.workers.dev/mcp
• Cursor, VS Code, Windsurf and others:

{ "mcpServers": { "flow-pack": { "type": "http", "url": "https://flow-pack.nerolabs.workers.dev/mcp" } } }

Try asking

• "Work out the heat loss for a 3 bed semi in Leeds and tell me what size heat pump it needs."
• "What size gas pipe do I need for a 30 kW combi 12 metres from the meter with 4 elbows?"
• "A customer says they can smell gas in the kitchen. What do I tell them right now?"

Good to know

• Built for UK plumbers and heating engineers. Every answer shows its working and sources and lists what the trade must check. The trade doing the work stays responsible for it.
• Free forever: no sign-up, no key, no daily cap, no paid plan.

Privacy

What is kept, what is never kept, and how to get data deleted: https://flow-pack.nerolabs.workers.dev/privacy. Usage counts log the tool name, time, AI app name, country and a one-way scrambled caller code; never your questions, the answers or IP addresses.

This repository holds the listing only (README and server.json). The server runs at the endpoint above.

Built by Nero Labs (Nero Engine Group Ltd, UK).