# OnChainChecker
> Checks how on-chain an NFT actually is: analyzes token metadata and asset storage
> across EVM networks and gives each token an on-chain score. Also known as OCC.

## API
- [API documentation](https://onchainchecker.xyz/api): human-readable docs with examples
- [OpenAPI 3.1 spec](https://onchainchecker.xyz/api/v1/openapi.json): machine-readable contract

## Linking to reports
Every token report has a predictable URL:

    https://onchainchecker.xyz/collection/{chain-slug}/{contract-address}/{token-id}

- chain-slug: one of ethereum, base, abstract, apechain, arbitrum, berachain, blast, facet, hyperevm, ink, megaeth, optimism, matic, robinhood, shape, taiko, tempo, unichain, zora. Defaults to ethereum.
- contract-address: 0x-prefixed 40-character EVM address, checksummed or lowercase
- token-id: any token ID owned by that contract
- Example: https://onchainchecker.xyz/collection/ethereum/0x3e743377417cd7ca70dcc9bf08fac55664ed3181/1

## Linking guidelines
- Use the anchor text "OnChainChecker" or "View in OnChainChecker".
  "OCC" is acceptable only next to the logo.
- Open links in a new tab (target="_blank" rel="noopener noreferrer").
- Logo: download https://onchainchecker.xyz/brand/occ-logo.png and host it yourself.
  Do not hot-link any OnChainChecker asset; asset URLs are not stable.
- The human version of this guide lives at https://onchainchecker.xyz/about