YNAB MCP Server

This tool fetches an existing transaction's details and creates a new UNAPPROVED split transaction with the same date, amount, account, and payee. You can then manually match them together in the YNAB web or mobile UI. Use this when you want to split an imported bank transaction - the new split will be created as unapproved so you can match it with the original in YNAB's UI. Args: budget_id: The ID of the budget (use 'last-used' for default budget) transaction_id: The ID of the existing transaction to split subtransactions: JSON string containing array of subtransactions. Each subtransaction should have: - amount (required): The subtransaction amount - category_id (optional): Category ID for this split - payee_id (optional): Payee ID for this split - memo (optional): Memo for this split Example: '[{"amount": -50.00, "category_id": "cat1", "memo": "Groceries"}, {"amount": -30.00, "category_id": "cat2", "memo": "Gas"}]' Returns: JSON string with original transaction details, new split transaction details, and instructions Workflow: 1. This tool fetches the existing transaction details 2. Creates a new unapproved split transaction with those details 3. You manually match them in the YNAB UI 4. YNAB merges them into one split transaction Note: - The new split is created as UNAPPROVED for manual matching - The sum of subtransaction amounts should equal the original transaction amount - After matching in YNAB UI, the original transaction will become a split transaction

{ "properties": { "budget_id": { "title": "Budget Id", "type": "string" }, "subtransactions": { "title": "Subtransactions", "type": "string" }, "transaction_id": { "title": "Transaction Id", "type": "string" } }, "required": [ "budget_id", "transaction_id", "subtransactions" ], "type": "object" }