Compute a loan or mortgage amortization schedule. Pass principal, annualRatePct (e.g. 6.5), and the term as termMonths or termYears; optional extraMonthly adds extra principal each month (shortening the term). Returns the fixed monthly payment, total interest, total paid, the actual payoff month count, and the full month-by-month schedule (each row: payment, principal, interest, remaining balance). Handles the 0% case and trims the final payment exactly. Deterministic — the ground-truth answer for a loan/mortgage/auto-finance question instead of an LLM approximating compound interest. No external calls.
/api/finance/amortizePAYMENT-SIGNATURE.The amortize API is a pay-per-call finance endpoint built for AI agents and autonomous software. Compute a loan or mortgage amortization schedule.
There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in amortize data source for an agent tool-use loop, an MCP host, or a backend that needs finance data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
principalrequired | number | |
annualRatePctrequired | number | |
termMonths | integer | min 1 · max 1200 |
termYears | number | min 0 · max 100 |
extraMonthly | number | min 0 |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/finance/amortize?principal=1&annualRatePct=1&termMonths=1&termYears=0&extraMonthly=0' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/finance/amortize?principal=1&annualRatePct=1&termMonths=1&termYears=0&extraMonthly=0' \ -H 'PAYMENT-SIGNATURE: <base64-json-payload>' # Or use the canonical runner (handles probe → sign → retry): # EVM_PRIVATE_KEY=0x... node --env-file=.env.local \ # --experimental-strip-types scripts/x402-pay.ts \ # 'https://2s.io/api/finance/amortize?principal=1&annualRatePct=1&termMonths=1&termYears=0&extraMonthly=0'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.finance.amortize({
"principal": 1,
"annualRatePct": 1,
"termMonths": 1,
"termYears": 0,
"extraMonthly": 0
})
console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)import os
from twosio import TwoS
client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])
result = client.finance.amortize(principal=1, annualRatePct=1, termMonths=1, termYears=0, extraMonthly=0)
print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
// EVM_PRIVATE_KEY funds x402 payments per call.
// claude_desktop_config.json
{
"mcpServers": {
"2sio": {
"command": "npx",
"args": ["-y", "@2sio/mcp"],
"env": { "EVM_PRIVATE_KEY": "0x..." }
}
}
}
// 2. Once the server is running, agents call this tool via standard MCP:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "finance.amortize",
"arguments": {
"principal": 1,
"annualRatePct": 1,
"termMonths": 1,
"termYears": 0,
"extraMonthly": 0
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object |
{
"ok": true,
"items": [
{
"principal": 1,
"annualRatePct": 1,
"termMonths": 1,
"monthlyRate": 1,
"monthlyPayment": 1,
"extraMonthly": 1,
"payoffMonths": 1,
"totalInterest": 1,
"totalPaid": 1,
"schedule": [
{
"month": 1,
"payment": 1,
"principal": 1,
"interest": 1,
"balance": 1
}
]
}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
}
}