# stampd
> The true cost of buying a UK home (England & Northern Ireland): Stamp Duty (SDLT)
> plus deposit, legal, survey, Land Registry, mortgage repayment and total cash on
> completion. Agent-first JSON API. SDLT rates effective 1 April 2025.

## API
- GET /api/calc?price=600000&buyer=standard&deposit_pct=10&rate=4.5&years=25&income=120000&non_resident=0
  -> {"ok":true,"input":{...},"result":{stamp_duty,deposit,loan,monthly_payment,land_registry_fee,total_upfront_cash,income_multiple,affordable,...}}
- POST /api/calc  (same fields as a JSON body)
- POST /v1/report/email  {"to":"a@b.com","price":600000,"buyer":"standard",...}  emails the breakdown

## Pro (paid)
The calculator + JSON API are free. stampd Pro (£29 one-off) mints a Pro key that
unlocks BRANDED estate-agent reports:
- POST /v1/checkout -> {"url":...}  Stripe Checkout; the Pro key is emailed on payment.
- POST /v1/report/branded  (header X-Stampd-Key: <key>)  {price,buyer,agency_name,agent_name,phone,email}
  -> a print-ready branded HTML one-pager (402 without a valid key).
- GET  /v1/pro/verify?key=<key> -> {"pro":true|false}

## buyer types
standard | first_time | additional ; non_resident=1 adds the 2% surcharge.

## Learn
GET /guide — full operating manual. CLI: `stampd guide` / `stampd help-json`.