create_category
Create a new category in the specified budget group.
LABSCO SUMMARY
A full read-write path into a budget, with the API's own unit and split semantics passed through unchanged.
Amounts are in milliunits, as get_budgets' description states, so a value written through create_transaction or update_category_budgeted is not the number a person types into the app. Splitting follows the API rather than the tool signature: when subtransactions are passed to update_transaction, the top-level amount and category_id are ignored and the total is derived from the subtransaction amounts — worth knowing before an update silently discards the figure you meant. Everything is scoped by budget_id, which get_budgets supplies, so the first call of any session is the same one.
What it is
A server over the YNAB API for one authenticated user, exposing budget, account, category and transaction reads alongside transaction and category writes.
What you get
- The budget's shape on the way in: get_budgets returns every budget for the authenticated user, get_accounts and get_categories take a budget_id, and get_budget_summary summarises a budget, optionally for one month.
- History filtered the way you would ask for it: get_transactions takes budget_id with optional account_id, category_id, since_date and limit.
- Transaction writes: create_transaction takes account_id, amount, date, payee_name, memo and category_id; update_transaction covers the same ground plus cleared, against a transaction_id; delete_transaction removes one.
- Splits as a first-class shape: create_split_transaction takes a subtransactions list and derives the total from it, and passing subtransactions to update_transaction converts an existing transaction into a split.
- Category management: create_category places a new category into a group_id, and update_category_budgeted sets the budgeted amount for a category_id in a named month.
Requirements
A YNAB account with an API token, supplied as YNAB_API_KEY.
Setup effort
One command plus a key — uvx ynab-mcp, then supply credentials
USE CASES
01
Logging a purchase without opening the budgeting app
Find the account and category it belongs against, then write the transaction with its payee, date and memo.
02
Splitting one receipt across the categories it really belongs to
Enter it as a split from the start, or convert a transaction already recorded as a single line by handing it the subtransactions.
03
Working out where the money went this month
Pull the month's summary, then narrow the transactions by account, category or a since_date to find what moved the number.
04
Moving money across when one category runs dry
Check the month against the categories, then set the budgeted amount on the ones that need to change.
05
Cleaning up a transaction that went in wrong
Find it in the history, correct the fields that are wrong, or remove it outright if it should never have been there.
11 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
create_split_transaction
Create a new split transaction in the specified budget. A split transaction divides a single transaction across multiple categories. The total amount is the sum of all subtransaction amounts.
create_transaction
Create a new transaction in the specified budget.
delete_transaction
Delete a transaction from the specified budget.
get_accounts
Retrieve all accounts for a specific budget.
get_budget_summary
Get a summary of the budget, optionally for a specific month.
get_budgets
Retrieve all budgets for the authenticated user.
Returns: Dictionary with budget data (all amounts in milliunits)
get_categories
Retrieve all categories for a specific budget.
get_transactions
Retrieve transactions for a specific budget, optionally filtered by date, account, or category.
update_category_budgeted
Update the budgeted amount for a category in a specific month.
update_transaction
Update an existing transaction in the specified budget. Pass subtransactions to convert the transaction into a split transaction divided across multiple categories; when doing so, amount and category_id at the top level are ignored by the API (the total is derived from the subtransaction amounts).
BEFORE YOU INSTALL
What to know first
Tools you get
11 tools when we connected.
Requires
- uvx on PATH
- YNAB_API_KEY in your environment
CONTEXT COST
Light Standing cost
Rated by the size of the 11 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Add the block to your client, or run the command directly.
Server setup
Configuration file
JSON
{
"mcpServers": {
"ynab-mcp": {
"command": "uvx",
"args": [
"ynab-mcp"
],
"env": {
"YNAB_API_KEY": "<YOUR_YNAB_API_KEY>"
}
}
}
}uvx
TERMINAL
uvx ynab-mcp
