A minimal NFT contract example shows how a contract can create a token record, associate a token identifier with an address, support ownership queries and transfers, and expose a reference to metadata. It does not, by itself, store or authenticate every associated file, establish rights in the referenced work, or show that an implementation is suitable for production.

What an NFT contract records

A smart contract is the on-chain program that applies its own rules to token records and related actions. In an NFT example, the contract’s state can record a token identifier and an address associated with that identifier. A transfer function can change that association according to the contract’s rules. These are statements about the token record, not a complete description of everything a person might mean by “owning the NFT.”

ERC-721 standardizes owner lookup, approvals, operator authorization, transfer behavior, and transfer events for distinct tokens. Those are defined behaviors for a conforming interface; they do not establish that any specific contract implements them correctly or that external rights exist. (source )

It is useful to keep three objects separate: the token record maintained by the contract, the metadata reference associated with the token, and the content or rights that may be described by that metadata. A contract example can show how the first object relates to the second. It cannot, simply by recording an address or URI, demonstrate that a referenced work is stored on-chain or that the token holder has rights in it.

NFT contract example: read the essential parts

The pseudocode below illustrates relationships, not an implementation in Solidity or any other named programming language. It is deliberately incomplete and is not deployable code.

contract ExampleNFT:
    owners: map<TokenId, Address>
    metadataReferences: map<TokenId, URI>

    function ownerOf(tokenId):
        return owners[tokenId]

    function createToken(recipient, tokenId, uri):
        owners[tokenId] = recipient
        metadataReferences[tokenId] = uri

    function transferToken(from, to, tokenId):
        require owners[tokenId] == from
        owners[tokenId] = to

    function tokenURI(tokenId):
        return metadataReferences[tokenId]

The owners mapping is a simplified way to express a relationship between token identifiers and addresses. ownerOf represents a query that returns the address recorded for a token. The example uses createToken to illustrate minting, a term for creating a token record and assigning initial ownership under a contract’s rules. Minting creates or assigns that token record; it does not, by itself, create, authenticate, store, or transfer rights in the referenced work or asset. (source )

transferToken sketches a change in the recorded address. Its single condition is only an illustration of the idea that a transfer must follow contract rules; it is not a complete authorization model. In particular, the pseudocode does not express the ERC-721 interface’s approvals, operator authorization, or transfer events. The standard describes those behaviors, but a short invented example cannot demonstrate that a real contract implements them correctly. (source )

The metadataReferences mapping and tokenURI function illustrate a reference that can be queried, rather than the contents of a media file. The example does not specify how the URI is created, what format its destination uses, or how another system retrieves it. Those choices are outside what this pseudocode establishes.

Ownership, transfers, and token standards

In this example, “owner” means the address the contract associates with a token identifier. A transfer changes that association under the contract’s rules. This technical meaning should not be broadened into a claim about the identity of the person or organization behind the address, the location of the associated content, or rights that are not represented in the contract.

A standard supplies a defined interface and behavior that an implementation can claim to follow. The example above is not a complete ERC-721 implementation: it omits standard-specific details and does not establish conformance. To understand a particular contract, a reader would need to distinguish its declared interface from its implemented behavior. Nothing in this example establishes that a token is compatible with every application or platform.

ERC-721 is relevant here because it specifies owner lookup, approvals, operator authorization, transfers, and events for distinct tokens. The example mentions those ideas only at a high level; it does not reproduce the full interface or all the rules an implementation must address. The function names in the pseudocode are illustrative labels, not claims about exact Solidity function signatures.

A separate standard, ERC-1155, shows why “one token equals one unique item” should not be assumed for every token contract. ERC-1155 allows one contract to manage multiple token types, including fungible, non-fungible, and semi-fungible configurations, and supports single and batch transfers. A token ID may have a quantity greater than one, so whether a particular ERC-1155 token is non-fungible depends on the implementation and its supply.

For the narrow purpose of reading a contract example, the key distinction is that a standard defines a pattern of token behavior, while an implementation supplies the actual contract state and code. A brief example may help identify a token ID, an ownership association, and a transfer concept. It does not establish every property of a given contract or every system that interacts with it.

How tokenURI connects a token to metadata

A token URI is a reference associated with a token. The ERC-721 metadata interface can expose a token URI referring to metadata for a specific token ID. The URI is not the metadata document itself, and the metadata document is not necessarily the image or other content it describes. In a typical conceptual flow, a contract returns a URI; an application uses that reference to locate metadata; and the metadata may identify additional content. This explains the roles of the pieces without asserting that every implementation uses the same storage or retrieval path.

The distinctions matter when interpreting code. The contract state may contain an identifier and an address, while its metadata function returns a reference. A reference can point beyond the contract’s own token record. The pseudocode does not show the bytes of an image, a metadata schema, or a system that hosts or serves either one.

The ERC-721 metadata interface does not guarantee that referenced content is available, permanent, accurate, or licensed. Those properties cannot be inferred from the presence of a tokenURI function or a stored URI; they depend on the implementation and the systems to which the reference leads. (source )

Accordingly, the example is useful for recognizing a link between token state and a metadata reference, not for deciding how content is stored or preserved. It also cannot authenticate a referenced file or establish what rights, if any, accompany the token. A reader should avoid treating the URI as proof of those separate properties.

What a short example cannot establish

The pseudocode leaves out important implementation details by design. It does not provide a full standard interface, a complete authorization design, or validation rules for token creation and transfer. It also does not include tests, security review, or evidence that the code has been deployed or examined. The example is explanatory, not an audit or production recommendation.

Likewise, the code cannot establish behavior that is outside its stated model. It gives no basis for conclusions about recovery options, fees, yields, service availability, or compliance. Those subjects cannot be inferred from a token mapping, a transfer sketch, or a metadata reference.

A practical reading sequence is therefore limited but useful: identify what value serves as the token identifier; find which contract state associates it with an address; locate the functions or interface describing transfers; and determine whether metadata is returned as a reference rather than assumed to be embedded content. Then keep conclusions within what the code and applicable standard actually specify.

In short, an NFT contract example can make the basic representation visible: a token record, an address associated with it, transfer-related behavior, and a possible metadata reference. It leaves implementation correctness, standard conformance, referenced-content properties, and external rights unresolved. The example explains a technical pattern; it does not answer those separate questions.

Sources and references