Defrr MCP Server

defrr MCP server

Revenue recognition (RevRec) schedules, waterfalls, renewals, credits, cancellations and usage pricing for contracts, worked out by defrr's engine. Connect it to Claude Code and ask in plain English, or call it from your own code.

The calculation tools store nothing, and nothing you send to them is logged. If you want, you can also switch on saving to your defrr organization (see below): contracts and renewals are saved as drafts a person approves, and usage products can be set up. That is off by default and set per key.

Connect

1. Create an API key at https://defrr.com/developers/account (40 free credits).

2. Add the server:

   claude mcp add --transport http defrr https://defrr.com/v1/mcp \
     --header "Authorization: Bearer dfr_live_YOUR_KEY"
   

3. In Claude Code, type /mcp. defrr should show 9 tools for a key that only calculates, or 19 or 24 for a key that can also save contracts (see below).

Tools

These calculate and store nothing. They work for every key.

A call that fails is refunded.

No key needed to look. Without a key, a client can open a session and list the 9 calculation tools above, so you can see what defrr does before signing up. Every tool call, and anything else, still needs a key.

Saving to defrr (optional)

By default the tools above only calculate: the schedule comes back to you and nothing is kept. If you want contracts and renewals recorded in your defrr organization, create a key with Save contracts in Defrr ticked on your developer account. If you don't have a defrr workspace yet, the page sets up a small one for you (company name, base currency, how revenue is recognised and, if you like, the month your books are locked through). A key without that option can only calculate.

A saved contract is a draft. It isn't live, and no report reads it, until it is approved: in defrr under Contracts, Draft contracts, or by an agent whose key also has the approve option. Leave the approve option off for an agent you want a person to check. If a draft has revenue in months you have closed (your locked period in Organization details), or in months that have already ended, defrr says so before it is approved.

Foreign currency. For a deal priced in another currency, send currency (such as EUR) and the term prices in it. Prices are converted to your organization's base currency at the exchangeRate you give (how much of your currency one unit of the foreign currency is worth), or at defrr's daily rate for the start date if you leave it out (defrr_get_exchange_rate shows it). If there is no rate the save is refused: a rate of 1 is never assumed. The draft keeps the foreign price, currency and rate, and renewals and corrections on that contract are made in its own currency.

Back-dated contracts. If a contract started in months your organization has already closed, save it with backdated: true (or, to see the effect without saving, pass lockedThrough to defrr_create_contract). The months from the start through the locked period are caught up together in the first open month, the way the defrr app does it, and the invoice is posted there too, so no closed month changes. It works with foreign currency and with renewals. A single term needs a quantity of 1, and the contract must run past the locked month. The result says how much lands in which month.

Repeats are safe. Sending the same agreement again returns the draft already saved and costs nothing, while that draft is waiting or approved. If it was rejected, or its contract has since been deleted, the same terms save as a new draft. Send an idempotencyKey to save a separate deal with identical terms.

A saved renewal is a draft too. When a customer renews, the agent finds the contract (defrr_find_contracts, then defrr_get_contract) and saves the renewal with defrr_save_renewal: the contract's id, the renewal's end date and the renewal term's total price. The contract does not change until the renewal is approved in defrr under Contracts, Draft renewals, or with defrr_approve_renewal_draft if the key may approve. Approving adds the renewal as a new last term and recalculates the contract's schedules. It only works on a contract whose terms can be read as a schedule (defrr_get_contract says why when it can't, for example monthly billing, a discount or adjustments recorded against it), only after the contract's last end date, and it refuses a renewal that starts in a closed period: process that one in the app under Edit renewals.

What the agent is told. When a session starts it learns which organization it is connected to, the last locked period, and when the key last connected. Only a person can change the locked period, in defrr under Organization details.

Be stepped through it

In Claude Code, start a new session and type:

/mcp__defrr__new-contract

It asks for anything missing (customer, product, each term's dates and price, how revenue is recognised), reads the terms back for you to confirm, then saves a draft. You can put what you already know after the command. Other MCP clients list the same prompt as new-contract on the defrr server, in their own menu. Or just ask in plain English: "Create a contract for Acme Pty Ltd, Pro Plan, 1 Jan 2027 to 31 Dec 2027 at $12,000".

A developer workspace

A workspace set up from the developer account page opens a few pages in the defrr app: the Dashboard, View all contracts, Draft contracts, Draft renewals, Usage products, the customer profile, and Organization details (the basic details, recognition model, base currency and locked period). The rest are subscription features and are shown greyed out.

It also has an Ask defrr assistant, a button at the bottom right of every page. It uses these same tools and your credits, and can also prepare the cancellation of a contract, or of its latest renewal: it shows the figures on a card and nothing changes until you press Confirm. It cannot approve drafts.

Try it

A new contract (calculate only):

Use defrr to create a contract: original term 1 Jan 2026 to 31 Dec 2026 at $12,000, then a renewal from 1 Jan 2027 to 31 Dec 2027 at $18,000. End dates are included. Recognise it smooth. Show me the terms and the month-by-month schedule.

A renewal:

Use defrr to process a renewal, recognised smooth with end dates included. The contract ran 1 Jan 2026 to 31 Dec 2026 at $12,000 and renews to 31 Dec 2027 at $18,000. Our books are closed through March 2027. Show the price change, the billing entry, any catch-up, and what to post by month.

Usage:

Use defrr to price usage for two customers. Acme is on volume pricing: the first 100,000 units a month at $0.002, then $0.001 a unit above that. They used 250,000 units in Jan 2026 and 80,000 in Feb 2026. Globex has prepaid credit: 100,000 units at $0.002 each. They used 70,000 units in Jan 2026 and 60,000 in Feb 2026. Show each month's revenue, the total by month, and any overage.

Saving a renewal (needs a key with the save option):

Acme Pty Ltd renewed their Pro Plan to 31 Dec 2028 for $14,000. Find their contract and save the renewal as a draft. Tell me which contract you used.

Saving a contract (needs a key with the save option):

Create a contract in defrr for Acme Pty Ltd, Pro Plan: 1 Jan 2027 to 31 Dec 2027 at $12,000, exact recognition, end date included. Tell me which organization it was saved to.

Other clients

Any MCP client that supports Streamable HTTP and custom headers can connect. Send your key either as Authorization: Bearer dfr_live_YOUR_KEY or as X-API-Key: dfr_live_YOUR_KEY (for tools that don't let you set Authorization). Never put a key in the web address.

Cursor

This repository is laid out as a Cursor plugin: the defrr connection (mcp.json, and the same file as .mcp.json for directories that look for that name), a rule that tells the agent when to use defrr (rules/defrr-revops.mdc), and a new-contract command that steps you through saving a contract (commands/new-contract.md).

The connection reads your key from an environment variable called DEFRR_API_KEY, so the key never goes into a file. Create a key at https://defrr.com/developers/account, then set the variable once:

• macOS (tested): in Terminal run

  launchctl setenv DEFRR_API_KEY dfr_live_YOUR_KEY
  

  Then quit Cursor completely (Cmd+Q) and open it again from the Dock or Applications folder, not by typing a command in Terminal. Cursor reads the variable when it starts, so reloading the window is not enough. The setting lasts until you restart your Mac: run the command again after a restart, or use the file-based setup below.

• Windows and Linux (not tested): set a user environment variable named DEFRR_API_KEY, then quit and reopen Cursor.

Then check Cursor's MCP settings: defrr should be ready and list its tools (9 for a key that only calculates, 19 or 24 for a key that can save contracts).

To use the plugin before it is in Cursor's marketplace, copy this folder to ~/.cursor/plugins/local/defrr/ and reload Cursor.

If you would rather keep the key in a file, or Cursor can't see the variable, it shows defrr as failed, often with Unexpected token '<', "<!DOCTYPE"... is not valid JSON in its MCP log. That message means the request reached defrr without a valid key. Add the server yourself in ~/.cursor/mcp.json (or Cursor Settings, MCP):

{
  "mcpServers": {
    "defrr": {
      "type": "http",
      "url": "https://defrr.com/v1/mcp",
      "headers": { "X-API-Key": "dfr_live_YOUR_KEY" }
    }
  }
}

Keep this file out of version control, and if you use the plugin as well, turn the plugin's own copy of the server off so the two don't clash.

LangChain

LangChain connects to MCP servers through its langchain-mcp-adapters package:

from langchain_mcp_adapters.client import MultiServerMCPClient

client = MultiServerMCPClient({
    "defrr": {
        "transport": "streamable_http",
        "url": "https://defrr.com/v1/mcp",
        "headers": {"X-API-Key": "dfr_live_YOUR_KEY"},
    }
})
tools = await client.get_tools()

Keep your key in an environment variable rather than in the code. See LangChain's MCP documentation for how to use the tools in an agent.

Larger sets

A revenue waterfall takes up to 50 contracts per call. For more, send them in batches and pass each response's carry into the next call: the last batch returns the grand total for all of them. For a big set (hundreds or thousands of contracts), call the API from a script instead of through the model, so the figures go straight into a file. The guide has a ready-made Python script that writes two CSV files.

Privacy

The calculation tools work from what you send in each request and keep nothing about it. The one exception is saving, which you switch on per key: a key with Save contracts in Defrr stores the contracts and renewals you send (customer, product, dates and prices) as drafts in your own defrr organization, and the usage products you create there.

Docs and limits

Full reference, pricing and what isn't covered: https://defrr.com/developers/guide

Registry listing: com.defrr/defrr