MCP · ChatGPT · Developer Mode

Use CivilQuants inside ChatGPT.

ChatGPT users can connect the CivilQuants MCP server today through Developer Mode and generate measured Bills of Quantities in chat: the free tier covers six assemblies measured to MMHW, no account needed.

CivilQuants is not currently listed in the ChatGPT app directory. The connector works via Developer Mode, set up once in about a minute.

§ 01 · Connect ChatGPT

Streamable HTTP @ api.civilquants.com/mcp
  1. 1

    Enable Developer Mode

    In ChatGPT, open Settings, then Apps & Connectors, then Advanced settings, and switch on Developer mode. Connector support requires a ChatGPT plan that includes connectors.

  2. 2

    Add the CivilQuants connector

    Still under Apps & Connectors, choose Create (or Add connector), name it CivilQuants, and set the MCP server URL to https://api.civilquants.com/mcp. No authentication is needed to start.

  3. 3

    Try a free computation

    Start a new chat with the connector enabled and ask for one of the six free assemblies, measured to MMHW. No account or card is required for the free tier.

  4. 4

    Sign in for the paid surface

    When a prompt needs a paid feature (the full catalogue, CESMM4, NRM2 or SMM7, drawings, saved projects, the QS skills), the connector replies with a sign-in route. Authenticate through the connector and the same tools unlock.

ChatGPT's settings layout changes from time to time. If the menu names differ, search the settings for "connector" or "developer mode"; the MCP URL stays the same.

§ 02 · Watch a full session

11 min 53 s · real ChatGPT session, unedited flow

One continuous ChatGPT conversation against the live connector: a free manhole bill and its derivation, a cantilever wall take-off with the Excel, DXF and PDF deliverables, the procurement schedule, saving and reloading a project, and a senior-QS risk assessment run through the skills surface.

§ 03 · Example prompts

Paste into ChatGPT with the connector enabled
  • Free

    "Using the CivilQuants tools, compute an MMHW Bill of Quantities for a precast concrete manhole 1.2 m diameter and 3 m deep. Do not estimate or calculate anything yourself, present the engine output as returned."

    A 20-row MMHW bill with the engine defaults stated, every quantity traceable to its derivation.

  • Paid

    "Using the CivilQuants tools, give me the take-off for a 2.5 m high reinforced-concrete cantilever retaining wall, 25 m long, with the Excel bill and the DXF and PDF drawing sheets."

    The wall bill plus signed download links for the Excel workbook, the PDF drawing sheet and the DXF. Rates come back null by design: CivilQuants measures, pricing stays yours.

  • Paid

    "List the CivilQuants skills using the list_skills tool, then fetch tender_risk_assessment with get_skill and apply it to the scope above."

    The 10 senior-QS skills listed, the tender-risk methodology loaded, and a TR-numbered risk register with mitigations built against your scope.

The engine is deterministic: the same prompt at the same parameters reproduces the same bill. Deliverable download links are signed and expire after 24 hours; re-running the call mints fresh ones.

The full tool reference lives on the agent docs.

56 tools, 11 prompts, 8 resources, troubleshooting, and quick-starts for Claude, Cursor and custom agents.