# mortgage_calculator

Calculate monthly mortgage payments, total interest, and amortization. Parameters: principal — Loan principal amount. rate — Annual interest rate (e.g. 5.5 for 5.5%). years — Loan term in years.

Agent View of the PolicyLayer registry record for `mortgage_calculator`. HTML page: https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/mortgage-calculator

## Facts

- Tool: `mortgage_calculator`
- Server: X402 Middleware (`@gadgethumans/x402`) — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware.md
- Install: `npx -y @gadgethumans/x402`
- Homepage: https://github.com/scotia1973-bot/gadgethumans-x402
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 3 (3 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `rate` | number | yes |  |
| `years` | integer | yes |  |
| `principal` | number | yes |  |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "mortgage_calculator",
    "arguments": {
      "rate": 0,
      "years": 0,
      "principal": 0
    }
  }
}
```

## Why mortgage_calculator is rated Low

This is a pure calculation tool that takes numerical inputs and returns computed financial metrics. It performs no write operations, does not execute arbitrary code, does not delete data, and does not process actual payments or financial transactions. Despite the financial context (mortgage/payments), the tool itself only reads/computes; it does not move money, charge accounts, or create financial obligations.

From the tool's own definition: "Tool description states it 'Calculate[s] monthly mortgage payments, total interest, and amortization' with parameters for principal, rate, and years."

## Use case

AI agents call mortgage_calculator to retrieve information from X402 Middleware without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches X402 Middleware:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "mortgage_calculator": {}
  }
}
```

## Other tools on X402 Middleware (57)

- `agent_memory` — Destructive — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/agent-memory.md
- `wallet_buy` — Financial — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/wallet-buy.md
- `x402_payment_request` — Financial — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/x402-payment-request.md
- `x402_pricing` — Financial — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/x402-pricing.md
- `x402_verify_payment` — Financial — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/x402-verify-payment.md
- `analyze_readability` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/analyze-readability.md
- `analyze_url` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/analyze-url.md
- `bmr_calc` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/bmr-calc.md
- `calculate_bmi` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/calculate-bmi.md
- `calculate_date` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/calculate-date.md
- `check_ssl_certificate` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/check-ssl-certificate.md
- `classify` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/classify.md
- `compare_items` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/compare-items.md
- `convert_currency` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/convert-currency.md
- `convert_timestamp` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/convert-timestamp.md
- `convert_timezone` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/convert-timezone.md
- `decode_jwt` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/decode-jwt.md
- `detect_language` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/detect-language.md
- `dns_lookup` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/dns-lookup.md
- `extract_contacts` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/extract-contacts.md
- `generate_seo_metadata` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/generate-seo-metadata.md
- `generate_uuid` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/generate-uuid.md
- `geocode` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/geocode.md
- `geolocate_ip` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/geolocate-ip.md
- `get_air_quality` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/get-air-quality.md
- `get_crypto_prices` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/get-crypto-prices.md
- `get_forecast` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/get-forecast.md
- `get_og_metadata` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/get-og-metadata.md
- `get_weather` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/get-weather.md
- `grammar` — Read — https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware/grammar.md
- …and 27 more: https://policylayer.com/tools/com-gadgethumans-swarm-x402-middleware.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-gadgethumans-swarm-x402-middleware · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-gadgethumans-swarm-x402-middleware