Blockchain & Cryptocurrency Glossary

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

  • search-icon Clear Definitions
  • search-icon Practical
  • search-icon Technical
  • search-icon Related Terms

Metadata URI

1 min read
Pronunciation
[met-uh-day-tuh yoo-ahr-eye]
Analogy
Like a link on a museum placard telling you where to find more detailed information about the artwork online.
Definition
A Uniform Resource Identifier (URI) stored in a token contract (e.g., ERC‑721 `tokenURI`) that points to off‑chain metadata JSON describing the token’s attributes, image, and other properties.
Key Points Intro
Metadata URIs link on‑chain tokens to descriptive off‑chain data for rich NFTs and tokens.
Key Points

URI format: Typically HTTP(S) or IPFS URIs.

JSON schema: Attributes like name, description, image, properties.

On‑chain pointer: Contract `tokenURI(tokenId)` returns the URI.

Decentralization: IPFS or Arweave preferred for permanence.

Example
An ERC‑721 contract’s `tokenURI(1)` returns `ipfs://Qm.../1.json` containing name, image link, and traits.
Technical Deep Dive
Contract stores a base URI and concatenates `tokenId` and `.json`. Off‑chain, a metadata server or IPFS gateway serves JSON with keys: `{"name":"MyNFT","description":"...","image":"ipfs://..."}`.
Security Warning
Mutable HTTP metadata can be tampered; use content‑addressed storage for integrity.
Caveat
On-chain storage of large metadata is expensive; URIs assume off-chain availability.
Related Terms
IPFS Hash
Arweave

Metadata URI - Related Articles

No related articles for this term.