Sumline for ChatGPT

Use Sumline inside ChatGPT

Ask about a property deal in plain English. Sumline supplies verified seller net proceeds, buyer costs, rental returns and mortgage payments from the same calculation engines behind every Sumline report.

Add Sumline to ChatGPT Open the Sumline calculators

Start using Sumline in ChatGPT

Open the Sumline plugin page and add Sumline to ChatGPT.
Start a new chat and choose Sumline from Tools, or type @Sumline.
Sign in to your Sumline account and approve the connection when ChatGPT asks.
Describe the deal in plain English and include the numbers you already know.

Prompts to try first

Copy one into ChatGPT, replace the example numbers with your own, and Sumline will supply the verified figures.

Seller net proceeds

My seller is listing in North Carolina at $525,000 with a $285,000 mortgage payoff. Use Sumline to calculate their estimated net proceeds, then explain the main assumptions in plain English I can read out to them.

Buyer closing costs & cash to close

My buyer is purchasing at $425,000 with 20% down on a 30-year fixed at 6.5%. Use Sumline to calculate their estimated cash to close and monthly payment, then summarise it as a short note I can text them.

Rental property ROI

Run a rental analysis with Sumline: $400,000 purchase price, 25% down, 7% interest over 30 years, $3,200 monthly rent. Give me the monthly cash flow, cap rate and cash-on-cash return, and tell me which assumption matters most.

Mortgage payment

Use Sumline to calculate the principal-and-interest payment on a $340,000 loan at 6.5% over 30 years, then explain in plain English what principal-and-interest includes and what it does not include.

How it works

Step 1
Ask in your own words
Type the deal the way you'd describe it to a colleague — price, payoff, down payment, rent. No forms, no field names.
Step 2
Your assistant sends the numbers to Sumline
It passes only the figures needed for the calculation to Sumline's tools, and waits for the answer.
Step 3
Sumline returns the verified result
The figures come from the same calculation engines behind Sumline's calculators and client reports. Your assistant then explains them conversationally — it doesn't produce the math itself.

Also use Sumline with Claude

Verified

Claude remains a supported alternative, tested end-to-end with Sumline production. You'll need a Sumline account and a Claude account. Labels can move slightly between Claude versions — look for the closest match.

Open Claude on the web or in the desktop app and sign in.
Go to Settings, then Connectors.
Choose Add custom connector.
Name it Sumline.
Paste the Sumline connection address above into the URL field.
Choose Add (or Connect) to save it.
Sign in to your Sumline account if you're asked to.
Read the Sumline permission screen, then choose Approve and connect.
Start a new chat with Sumline switched on in Claude's tools or connectors area, then ask your question.

Sumline connection address

https://usesumline.com/mcp

What's included

Free account

5 valid AI-assistant calculations per day.

Estate Pro

Unlimited AI-assistant calculations, plus everything else Estate Pro includes — unlimited branded PDF reports and client shares carrying your name, photo and brokerage.

See Estate Pro pricing

Your assistant asks. Sumline calculates.

Sumline receives only the calculation inputs your assistant sends to the Sumline tools — not your whole conversation.
Connecting never gives the assistant your Sumline password. You sign in on Sumline and approve the connection yourself.
You can disconnect Sumline from your AI assistant at any time.
Results are software-modeled estimates for discussion — not lending, legal, tax, appraisal or financial advice.

When it's time to send something to the client

Use your assistant for quick numbers and conversation. When the client needs something polished, open Sumline for the full calculator, a branded client-ready PDF or share link, and Seller-ready and Buyer-ready reports you review and approve before they go out.

Open the seller net sheet Open the buyer calculator

Advanced — technical details for developers

Sumline publishes a remote MCP (Model Context Protocol) server at https://usesumline.com/mcp.

Four read-only tools are available:

Seller Net Proceeds
Buyer Closing Costs
Rental Property ROI
Mortgage Payment

Prefer an API key instead of a browser connection? Get a Sumline API key.

Explore more Sumline tools

State-specific calculators and in-depth guides.

For agents

Rental property calculator by state

Seller net proceeds by state

Guides

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