Basesheet

Guides

How to use Basesheet in ChatGPT and Claude

Add https://basesheet.site/mcp as a custom connector. In Claude: Settings, Connectors, Add custom connector, paste the address. In ChatGPT: turn on Developer Mode, then create a connector with the same address and no authentication. Then ask something like "Site context for 500 Capitol Way S, Olympia, WA". No sign-in or API key is needed.

Claude

  1. Open Settings → Connectors (in the Claude apps or at claude.ai).
  2. Choose Add custom connector. Name it Basesheet and paste https://basesheet.site/mcp as the URL. Leave the authentication settings empty.
  3. In a chat, make sure Basesheet is switched on in the connectors menu, then ask for a property.

Custom connectors are in beta. Free plans can add one; on Team and Enterprise plans an owner adds the connector for the organization first.

ChatGPT

  1. Open Settings → Apps & Connectors → Advanced settings and turn on Developer mode.
  2. Back in Apps & Connectors, choose Create. Name it Basesheet, paste https://basesheet.site/mcp as the server URL, and choose No authentication.
  3. Start a chat, add Basesheet from the tools menu in the message box, and ask for a property.

Developer mode is a beta, and which ChatGPT plans include it has changed over time; check OpenAI's help center if you don't see it. ChatGPT warns that custom connectors aren't reviewed by OpenAI; Basesheet's connector only reads public data and sends you a link.

Other MCP clients

Cursor, VS Code and other tools that support remote MCP servers over HTTP can add the same address. For clients that take JSON:

{"mcpServers": {"basesheet": {"url": "https://basesheet.site/mcp"}}}

What to ask

The answer lists the key facts and a link to the result page, where you download DXF, SketchUp, Civil 3D, GIS and PDF files. Like everything Basesheet makes, it's public GIS data: not a survey, not a certified site plan and not for permit submission.

Everything here is planning-level public data. Confirm boundaries, topography, wetlands and flood status with a licensed surveyor and the right specialists before design decisions depend on them.

Basesheet does all of this for any US address in about 30 seconds, free, with no account.

Try it free

Related

Updated October 2026.