# FactStamp pricing

Every price below is **per call**, paid in USDC on Base over x402, or drawn from a prepaid pack bought
by card or with PayPal at https://factstamp.agentrails.workers.dev/packs. A call that returns no answer is not a charge on a prepaid pack, and a
hard failure on the x402 rail returns an error instead of settling.

| Door | Path | Price per call |
|---|---|---|
| `check_entity` | `POST /entity` | US$0.10 |
| `check_entity_file` | `POST /entity-file` | US$0.44 |
| `check_figure` | `POST /check` | US$0.05 |
| `verify_citation` | `POST /citation` | US$0.02 |
| `verify_package` | `POST /package` | US$0.02 |
| `check_document` | `POST /document` | US$0.25 |
| `watch_add` | `POST /watch` | US$0.50 |
| `watch_portfolio` | `POST /watch/portfolio` | US$5 |
| `verify_bulk` | `POST /bulk` | US$0.12 |

## The entity file, priced in pence

The entity file (`POST /entity-file`, MCP `check_entity_file`) is priced in **pence as the source of
truth**: 33p UK-facing. The USDC amount that actually settles,
**438119 base units** (US$0.44), is derived from that pence price at
the dated GBP/USD rate — **0.75322 on 2026-10-06**, from
European Central Bank euro foreign exchange reference rates (via frankfurter.dev) — and rounded down, in the buyer's favour, so it can never exceed the
quoted price. The rate, its own date and its source ride on the answer and in the signed receipt, so
what settled and on what basis is checkable by somebody who was not here.

## Standing work, stated per unit

- **A watch** (`POST /watch`) is US$0.50 for 30 days of daily re-checks:
  1.7 cents a check, where a single lookup is US$0.02.
- **A portfolio** (`POST /watch/portfolio`) is US$5 for up to
  25 references: US$0.20 a reference, about
  0.67 of a cent a check.
- **A bulk list** (`POST /bulk`) is US$0.12 for up to 12 items:
  1 cent an item, against US$0.02 for the same lookups one at a time.

## Free

No payment, no account: `/health`, `/series.json`, `/llms.txt`, `/docs`, `/pricing.md`,
`/openapi.json`, `/.well-known/*`, and the document preview (`"preview": true`) which lists the
claims a document contains and the exact price, with no verdicts.

## What the price buys

A verdict from a named publisher's own dated series or from the open registers, cited, with an
Ed25519-signed receipt that verifies offline against `https://factstamp.agentrails.workers.dev/.well-known/factstamp-issuer.json`.
No model sits in the verdict path: the same question, the same registry and judge versions and the
same snapshot reproduce the same answer.

## Paying

- **Per call (x402):** the manifest is at https://factstamp.agentrails.workers.dev/.well-known/x402. An unpaid call returns HTTP 402
  carrying the challenge; the facilitator settles the USDC on Base.
- **Prepaid packs (card or PayPal):** the ladder, its per-call rate and its expiry are on https://factstamp.agentrails.workers.dev/packs.
- **Pack codes** are presented as `authorization: Bearer ***.

Questions about a price, an invoice or a refund: info@alpineai.com.au.