calculate_cc_payoff

ai.senaro/personal-finance · Verify this server

Calculation, not advice. Verify with a professional before acting. Calculate credit card payoff timeline with month-by-month amortization. Supports dual APR segments (purchase + cash advance), two strategies (avalanche, snowball), fixed/dynamic payment modes, and an optional schedule of one-time windfalls (tax refund, bonus, inheritance) applied at specific months. Returns debt-free date, total interest, per-card payoff order, first_month_interest_ratio_frac (the first month's interest/payment fraction) and lifetime_interest_ratio_frac (whole-projection total_interest/total_paid fraction), domain warnings emitted as warnings[].type (DEATH_SPIRAL, CA_TRAP, MIN_PAYMENT_TRAP, DAY_ZERO_COST, DEBT_GROWING, PROMO_CLIFF, PREDATORY_RATE, SPEND_EXCEEDS_PAYDOWN, PLAN_TERM_ELAPSED_WITH_BALANCE), separately validation disclosures emitted as warnings[].code (MINIMUM_PAYMENT_NOT_BINDING on the default dynamic-budget path, MINIMUM_PAYMENT_NOT_BINDING_IN_BASELINE when fixed_payments = true; these two shapes coexist in the same warnings[] array but are distinguishable by which keys each entry carries), and when a plan exists (extra_monthly_payment > 0, windfalls present, or fixed_payments = true) a min_payments_only baseline block with interest_saved_vs_min_payments and months_saved_vs_min_payments quantifying the interest and time difference versus paying minimums only. When windfalls are also present the response additionally gains a baseline vs with_windfalls savings block. The response echoes strategy (canonical lowercase 'avalanche' | 'snowball', the strategy the plan was actually simulated under) at the top level. The response includes `chart_hints` with rendering directives any client can use. The `senaro-charts` MCP server renders them locally over stdio only. Use output: 'summary' (default) for a compact response or 'inline' for the full payload. output: 'capture' writes the full payload to a file on this server's local disk and returns a capture_ref URI for chart rendering; available on the local stdio transport only, and rejected with a structured error on the hosted HTTP transport, where a capture_ref would be a dead link for a remote caller. Top-level `entered_starting_balance` echoes the caller's supplied balances by segment type (`total`, `purchase`, `cash_advance`, `balance_transfer`, `promotional`, `installment_plan`), before any fee, recurring spend, or interest posts; `total` is the sum of the other five. Top-level `total_purchase_segment_fees_paid` reports the portion of card fees (plan_fees_monthly plus annual_fee accruals) charged to the purchase segment across the projection, also present on every monthly_totals[] and analysis.buckets[] row. These month counts are each a {status, value, explanation} object rather than a bare month count: months_to_payoff, min_payments_only.months, minimums_only_baseline.months, and, when windfalls are supplied, baseline.months and with_windfalls.months. status is "defined" with an integer value when that plan reaches a zero balance, and "none" with value null when it does not, in which case explanation says why. The per-card payoff month inside card_payoff_order[] does not use the {status, value, explanation} object. It is still a bare integer.