Model Context Protocol

Gut8en for AI assistants (MCP)

Calculate German property depreciation (AfA) with the remaining useful life (Restnutzungsdauer) and the purchase price allocation (Kaufpreisaufteilung), check appraisal prices and book a free initial call — directly in Claude, ChatGPT, Cursor and every other client that supports the Model Context Protocol. Open source, free, no account needed.

Connect now View on GitHub

Open source (MIT)
Free, no login
Bookings only with your e-mail code

How it works

From question to answer — or a booked call

The Model Context Protocol (MCP) is an open standard that lets AI assistants call external tools. Instead of guessing, your assistant asks our calculation, our current prices and our free slots.

Learn more at modelcontextprotocol.io

1
Connect once
Add the server URL to Claude, ChatGPT or your IDE. No account, no API key.
2
Ask in plain language
Describe the property. The assistant picks the right tool and fills in the details.
- AfA rate
- Remaining useful life
- Annual tax effect
3
Get figures, prices and appointments
Results come from the same calculation and price list as our website, with the source cited. A call is only booked once you confirm the code we e-mail to you.

Tools

Five tools, ready for your assistant

Calculations, prices and free slots are read-only. Booking a call creates an appointment only after you confirm it with a code we e-mail to you. No tool triggers payments or accesses your conversations.

Property depreciation (AfA)

calculate_property_depreciation

Estimates the depreciation rate based on the remaining useful life, the annual and monthly depreciation and the resulting tax effect.

You provide

Property type
Construction year
Living area
Purchase priceoptional
Modernization statusoptional
Core renovation yearoptional
Plot size & land valueoptional
Marginal tax rateoptional

You get back

AfA rate vs. standard rate
Remaining useful life
Annual & monthly depreciation
Annual & monthly tax savings
Building value

read-only
idempotent
non-destructive

Open the web calculator

Purchase price allocation

calculate_purchase_price_allocation

Splits the purchase price into the non-depreciable land share and the depreciable building share using the BMF worksheet (Arbeitshilfe).

You provide

Property type
Purchase price
Purchase date
Construction year
Living area
Plot size
Standard land value
Purchase costsoptional
Co-ownership shareoptional
Net cold rentoptional
Garages & parkingoptional

You get back

Land and building value
Building share in percent
Depreciation base
Income and asset methods compared

read-only
idempotent
non-destructive

Open the web calculator

Appraisal prices

get_price_by_product

Returns the current list price of an appraisal product, including the options you pick when ordering: inspection, express processing and the per-flat price for multi-unit buildings.

You provide

Product
Inspectionoptional
Express processingoptional
Property type & flatsoptional

You get back

Base price
Surcharges per option
Total price in EUR incl. VAT
All options compared

read-only
idempotent
non-destructive

View the product

Free initial-call slots

get_available_appointments

Lists open slots for a free, non-binding 15-minute phone call with the team, on weekdays in German time.

You provide

Start dateoptional
Days aheadoptional

You get back

Free slots per day
Times in German time
Link to book on the website

read-only
non-destructive

Book on the website

Book the initial call

book_appointment

Books one of those slots in two steps: we e-mail you a 6-digit code, and only the code you give your assistant confirms the booking. You then receive a calendar invitation.

You provide

Chosen slot
Name
E-mail address
Phoneoptional
Code from the e-mail

You get back

Confirmed date and time
Calendar invitation by e-mail

creates a booking
sends an e-mail
non-destructive

Book on the website

Setup

Connect in under a minute

Use the hosted server URL below. No API key or account is required.

Server URL

https://mcp.rundum.immo/mcp

Claude (web & desktop)

Open Settings → Connectors → Add custom connector, enter a name and paste the server URL.

ChatGPT

Enable developer mode under Settings → Apps & Connectors → Advanced, then create a new connector with the server URL and no authentication.

Run locally (stdio)

Prefer to run the server on your own machine? Use the npm package (Node.js 22.12 or newer):

mcp.json

{
  "mcpServers": {
    "rundum-immo": {
      "command": "npx",
      "args": [
        "-y",
        "@rundum-immo/real-estate-appraisal-mcp"
      ]
    }
  }
}

Claude Code

Run this command in your terminal:

Terminal

claude mcp add --transport http rundum-immo https://mcp.rundum.immo/mcp

Cursor & other MCP clients

Add the server to your mcp.json:

mcp.json

{
  "mcpServers": {
    "rundum-immo": {
      "url": "https://mcp.rundum.immo/mcp"
    }
  }
}

VS Code

Add the server to .vscode/mcp.json:

.vscode/mcp.json

{
  "servers": {
    "rundum-immo": {
      "type": "http",
      "url": "https://mcp.rundum.immo/mcp"
    }
  }
}

Examples

Try these prompts

Paste one into your assistant once the server is connected.

“Estimate the German depreciation and annual tax effect for a 1970 condominium with 85 m², bought for €350,000, using a 42% marginal tax rate.”
→ calculate_property_depreciation
“My German rental house is from 1972 – can I depreciate it faster than 2% a year?”
→ calculate_property_depreciation
“Calculate the German purchase-price allocation for a condominium bought on 2024-06-15 for €500,000, with €40,000 purchase costs, built in 1975, 75 m², 1,200 m² land, €2,500 standard land value, and a 75/1000 co-ownership share.”
→ calculate_purchase_price_allocation
“Calculate depreciation for a 1985 apartment building with 95 m² and €420,000 purchase price; explain which missing modernization details would materially change the estimate.”
→ calculate_property_depreciation
“What does a Verkehrswertgutachten cost with an on-site inspection and express processing?”
→ get_price_by_product
“Book me a free initial call with the team for Thursday morning.”
→ get_available_appointments → book_appointment

For developers

Technical reference

Hosted server: https://mcp.rundum.immo/mcp
Transport: Streamable HTTP (stateless); stdio via npm
Protocol versions: 2025‑11‑25, 2025‑06‑18, 2025‑03‑26, 2024‑11‑05, 2024‑10‑07
Authentication: None — bookings are confirmed with a code sent by e-mail
Capabilities: Tools (no resources, no prompts)
Rate limits: 30 requests per minute, 500 per day per IP
Source code: github.com/Rundum-Immo/real-estate-appraisal-mcp
npm package: @rundum-immo/real-estate-appraisal-mcp
REST API (OpenAPI): /api/v1/openapi.json

Privacy

Data handling

The server is stateless and has no access to your conversations, files or memory.
Property details you send are used for the calculation only and are not stored.
If you book a call, we store your name, e-mail address and (optional) phone number to arrange it. The confirmation code is stored only as a hash and expires after 15 minutes.
To prevent abuse, we keep a salted hash of the IP address, the origin and the browser family for 30 days.
Read the privacy policy

Coming next

More Gut8en tools for signed-in customers are in preparation.

Results are indicative estimates based on German tax rules (including the ImmoWertV and the BMF worksheet for purchase price allocation). They do not replace tax, legal or appraisal advice. Prices are list prices incl. VAT; the price shown when ordering is binding. Initial calls are free and non-binding.

FAQ

Frequently asked questions

About the Gut8en MCP server

Yes. The hosted server and the open-source package are free to use, within the rate limits listed above.

No. The hosted server works without registration or an API key. Just add the server URL to your client. To book a call, you only confirm a code we send to your e-mail address.

Every client that supports remote MCP servers over Streamable HTTP, for example Claude, ChatGPT (developer mode), Claude Code, Cursor and VS Code. Clients that only support local servers can use the npm package.

The tools use the same calculation as our web calculators. The depreciation estimate depends heavily on the modernization status; without it, the result is an upper bound. For a figure the tax office accepts, you need a remaining useful life appraisal.

Yes. The adapter is MIT-licensed. You can run it locally via npx or build it from the GitHub repository. Calculations, prices and bookings stay on the Gut8en API.

Open an issue on GitHub or write to info@rundum.immo. Please report security issues privately to security@rundum.immo.

Yes, a free 15-minute initial call. Your assistant shows you the free slots; once you pick one, we send a 6-digit code to your e-mail address, and only the code you give your assistant confirms the booking. Your assistant only learns the confirmed time — you then receive a calendar invitation by e-mail.

Yes. All prices are list prices including 19% VAT; the tool also returns the net amount. Discount codes are applied when you order, and the price shown there is binding.

Still have questions? Our team is happy to help.

No AI assistant at hand?

Use the same calculation directly in your browser.

AfA calculator Purchase price allocation

Gut8en for AI assistants (MCP)

From question to answer — or a booked call

Connect once

Ask in plain language

Get figures, prices and appointments

Five tools, ready for your assistant

Property depreciation (AfA)

Purchase price allocation

Appraisal prices

Free initial-call slots

Book the initial call

Connect in under a minute

Claude (web & desktop)

ChatGPT

Run locally (stdio)

Claude Code

Cursor & other MCP clients

VS Code

Try these prompts

Technical reference

Data handling

Frequently asked questions

No AI assistant at hand?

Gut8en for AI assistants (MCP)

From question to answer — or a booked call

Connect once

Ask in plain language

Get figures, prices and appointments

Five tools, ready for your assistant

Property depreciation (AfA)

Purchase price allocation

Appraisal prices

Free initial-call slots

Book the initial call

Connect in under a minute

Claude (web & desktop)

ChatGPT

Run locally (stdio)

Claude Code

Cursor & other MCP clients

VS Code

Try these prompts

Technical reference

Data handling

Frequently asked questions

No AI assistant at hand?