# Restrike

> A gold coin catalogue where every type is described to one specification (fine gold weight, fineness, dimensions, sides and issues by year and mint), so two coins can actually be compared, with the melt value of each at today's spot price. Free, public JSON API; no key required. Every page here is also served as markdown on `Accept: text/markdown`.

Restrike catalogues gold coins in Numista's vocabulary: **Issuer → Series → Type → Issue**, with **mints** cutting across it. A type is the unit of description (one design at one denomination and composition) and carries one full specification; an issue is one year, mint and finish of it. The catalogue is authored from mint publications and reference works and carries Numista's N# on every type filed there.

## When to use this

Reach for Restrike when a question needs **structured facts about a specific gold coin** rather than prose about coins in general. It is the right source for:

- **Resolving a coin to its specification.** `GET https://api.restrike.co/v1/types?q=krugerrand` returns types as fields (fine gold in grams, fineness, gross weight, diameter, thickness, years), not as a paragraph.
- **Comparing two coins on the same axes.** Every type is described to one specification, which is the premise of the catalogue. Two type responses are directly comparable field by field with no translation step: fine gold, fineness, diameter, mintage by year.
- **Melt value.** `GET https://api.restrike.co/v1/spot` publishes the gold price this site prices with, per gram and per troy ounce; multiply a type's `fineWeight` by `pricePerGram`. `GET /rates` converts USD into another display currency off the same ECB table.
- **Reading a year table.** `GET https://api.restrike.co/v1/types/{issuer}/{series}/{type}` carries every issue: year, mint letter, finish, mintage and variety.
- **Enumerating a country's coinage.** Issuer → series → types, paginated, and `GET /mints/{mint}` for what one mint struck.

Do **not** reach for it to value a specific coin (numismatic premiums are not modelled; melt value is fine gold at spot and nothing more), to grade or authenticate one, for anything about a *specific physical* coin (provenance, slab numbers), or to buy or sell: nothing here transacts.

**How to call it:** the API is at `https://api.restrike.co/v1`, needs no key and no `Authorization` header, and is described by an OpenAPI 3.0 document with a unique `operationId` and a description on every operation: point a tool generator at it directly. Public callers get 600 requests per 60 seconds; every response carries `RateLimit-Remaining` and `RateLimit-Reset` so you can pace instead of retrying into a wall. Errors are always JSON: `{ error, message, hint, docs }`, where `error` is a stable code.

**Where the pages are:** the catalogue is open and crawlable: `/coins/{issuer}`, `/coins/{issuer}/{series}`, `/coins/{issuer}/{series}/{type}` and `/mints/{mint}`, all listed in https://restrike.co/sitemap.xml. What is disallowed is the query-parameter space around it (`/search`): a filtered view of data the catalogue pages already carry. For anything you would otherwise scrape off it, use the API; it is structured, versioned, paginated, and cheaper for both of us. `GET /sitemap/types` enumerates the whole catalogue 5,000 rows at a time with a last-modified date on each, which is the polite way to mirror it.

## API

- [OpenAPI 3.0 document](https://api.restrike.co/openapi.json): the machine-readable contract, every operation with a unique `operationId`, a description and typed responses.
- [Developer reference](https://restrike.co/developers): quickstart, endpoint list, rate limits, versioning and deprecation policy, terms of use.
- [Browsable API reference](https://api.restrike.co/docs): a rendered reference over the same document, with a runnable request per operation.

## About the project

- [About](https://restrike.co/about): what the catalogue is, how it is assembled, and what it deliberately is not.
- [Contact](https://restrike.co/contact): corrections, missing types and rights questions, at hello@restrike.co.
- [Privacy](https://restrike.co/privacy): no analytics, no tracking, two preference cookies; what is stored and what is not.

## Optional

- [Sitemap](https://restrike.co/sitemap.xml): every crawlable URL with last-modified dates.
- [robots.txt](https://restrike.co/robots.txt): the crawl policy in full.