AI apps

Claude, ChatGPT and Gemini can sort your personal expenses, and those of the groups you're in, into categories for you. OpenCount runs an MCP server at /mcp on your instance, and each person connects their own AI app under Account, AI apps.

#Connecting one

1. Copy the address shown under Account, AI apps, for example https://money.example/mcp.
2. Add it to your AI app: a custom connector in Claude, an app in ChatGPT, or a connected app in Gemini.
3. The app sends you to OpenCount: sign in if you aren't, then allow it.
4. Ask it to categorize your expenses, or a group's.

The app registers itself the first time it connects, through a Client ID Metadata Document when it publishes one, or Dynamic Client Registration otherwise, so there is nothing to set up for an admin. Gemini Enterprise, which wants a client ID and secret typed in by hand, is not supported.

#What it can do

It can list your groups, list the categories of your personal expenses or of a group and add new ones (with an icon), list the expenses (the uncategorized ones by default), and file them under a category. In a group it can also list the merchants, add one, and put merchants on expenses; personal expenses have no merchants. Adding a category or merchant that already exists under that name, whatever its case, hands back the existing one instead of a copy. It can also write or clear the note on your expenses or a group's, and sort your personal expenses into folders. For each expense it sees the description, note, amount, currency, date and category, and for a personal one whether it's an expense or income and its folder. It can list your bank accounts with their type, whether they're shared and their latest balance (synced or typed in, with its date), and record a balance for an account your bank doesn't report; each personal expense names the account it came from. It can list your recurring payments (amount, how often, next date, payments left, the account they come from) and file an expense as recurring, or out of it. It can sum up any period (by default since your last payday, when your months follow your pay): income, spending by category and by account, savings and finance apart, and what is left to spend until your next payday and per day, from the accounts it's told to count. Its expense list can be narrowed by dates, account, category, kind and search. It only reaches groups you're in, and a category or note it sets in a group changes it for everyone there; transfers between members are left alone. It never sees your email, password, bank credentials or keys, who's in a group, who paid, the splits or the balances.

#Staying in control

An app keeps access for 30 days after you allow it. After that its tokens are deleted and it has to send you through sign-in and consent again. Revoke one sooner under Account, AI apps: it stops working on its next request, not when its current token runs out.

AI apps need the instance on HTTPS (or localhost while developing): OAuth refuses anything else, and Account, AI apps says so when it can't offer the address.

#For admins

Sign-in for AI apps is an OAuth 2.1 authorization server inside OpenCount, with its discovery documents under /.well-known/ and its endpoints under /api/auth/oauth2/. A reverse proxy has to pass both through, along with /mcp. To read a Client ID Metadata Document, the server fetches the URL the app gives as its client ID, only over HTTPS, only to a public address, without following redirects.