Use catetin.ai with Claude and ChatGPT

The catetin.ai connector lets Claude and ChatGPT read your catetin.ai groups, transactions, and summaries, and record transactions for you after you confirm them. It uses the Model Context Protocol (MCP) and signs you in with your own catetin.ai account.

What you need

A catetin.ai account. Sign up for free in the catetin.ai app with Google or Apple.
At least one group in catetin.ai to read from or record into.
A Claude or ChatGPT account that can use connectors.

Connect in Claude

In Claude, open Settings → Connectors and find catetin.ai in the directory. If it isn't listed for you yet, choose Add custom connector and enter https://api.catetin.ai/mcp.
Select Connect and sign in with the Google or Apple account you use for catetin.ai.
Review the permissions and approve them.
Start a chat and ask about your finances, for example the prompts below.

Connect in ChatGPT

Find catetin.ai in ChatGPT's apps and select Connect. If it isn't available to you yet, add it in developer mode with https://api.catetin.ai/mcp.
Sign in with the Google or Apple account you use for catetin.ai and approve the permissions.

Permissions

You approve these permissions when you connect. The connector can only reach groups you are a member of, and every request is checked against your account on the catetin.ai server.

Permission	What it allows
`catetin.groups.read`	See the names, currencies, and timezones of groups you belong to.
`catetin.transactions.read`	Read categories, transactions, and financial summaries in those groups.
`catetin.transactions.write`	Create, update, or delete transactions after you confirm each change.
`catetin.messages.write`	Save a chat message and reply to a group conversation when you ask it to.
`catetin.subscription.read`	Read your plan and remaining AI quota.

Tools

Tool	Type	What it does
List groups `catetin_list_groups`	Read	Lists the catetin.ai groups you can access.
List categories `catetin_list_transaction_categories`	Read	Lists income and expense categories for a group.
Search transactions `catetin_search_transactions`	Read	Finds transactions by date range, category, or text (up to 100 per call).
Financial summary `catetin_get_financial_summary`	Read	Returns income, expense, balance, and a category breakdown for a period.
Subscription usage `catetin_get_subscription_usage`	Read	Shows your plan and how much AI quota you have used and left.
Prepare create transaction `catetin_prepare_create_transaction`	Write (draft)	Prepares a new transaction as a draft preview. Nothing is saved yet.
Prepare update transaction `catetin_prepare_update_transaction`	Write (draft)	Prepares a change to an existing transaction as a draft preview.
Prepare delete transaction `catetin_prepare_delete_transaction`	Write (draft)	Prepares the deletion of a transaction as a draft preview.
Commit transaction draft `catetin_commit_transaction_draft`	Write	Applies a prepared draft, only after you confirm it.
Record external chat turn `catetin_record_external_chat_turn`	Write	Saves one message and reply to a catetin.ai group conversation, only when you ask to save it.

How changes are confirmed

Transactions are never changed in one step:

The assistant prepares a draft and shows you a preview of the change.
Nothing is saved until you confirm. Drafts expire after 15 minutes.
On confirmation, catetin.ai checks your access again and applies the change once, even if the request is retried.

Example prompts

“How much did my Family group spend on food last month?”
“Add a lunch expense of Rp45.000 today to my Personal group.”
“Show my income and expenses for this week and the biggest categories.”
“Change yesterday's coffee transaction to Rp30.000.”
“How much AI chat quota do I have left?”

Usage and quota

Reading groups, categories, transactions, summaries, and usage does not use your catetin.ai AI quota.
Saving a chat turn to a catetin.ai conversation counts toward your chat quota, the same as chatting in the app. A failed or repeated save is not counted twice.
The assistant's own replies run on Claude or ChatGPT and are covered by your plan there.

Data and privacy

catetin.ai only receives what the assistant sends through these tools. Your other conversations with Claude or ChatGPT are not visible to catetin.ai.
A conversation turn is stored in catetin.ai only when you ask to save it. Transactions you confirm are stored in your group like any other transaction.
catetin.ai does not sell or rent your personal data.
Data you share with the assistant is also handled under Anthropic's or OpenAI's terms.
Read the full Privacy Policy and Terms of Service.

Disconnect

In Claude, open Settings → Connectors and disconnect catetin.ai. In ChatGPT, disconnect it from the app's settings.
Disconnecting stops new access. To delete your catetin.ai data, delete your account in the app under Settings → Edit Profile → Delete Account.

Troubleshooting

Sign-in fails with Apple: sign in to the catetin.ai app with Apple once, then connect again.
“Draft expired”: ask the assistant to prepare the change again and confirm within 15 minutes.
Missing groups or transactions: make sure you signed in with the same account you use in the app, and that you are a member of the group.
Out of quota: saving chat turns needs chat quota. Check your plan with “How much AI chat quota do I have left?”

Support

Email info@catetin.ai for help with the connector, or privacy@catetin.ai for privacy requests.