NFT Metadata Extension

The R402 Metadata Extension defines how NFT or digital asset metadata can declare rental or licensing terms directly inside its JSON metadata.
This allows marketplaces, wallets, and clients to discover pricing and initiate rentals without calling an external API.

🧩 Example Metadata Structure


{
  "name": "Rare Poster #001",
  "description": "Limited edition artwork available for short-term rental.",
  "image": "ipfs://bafy...poster.png",
  "attributes": [{ "trait_type": "Artist", "value": "DigitalFlux" }],
  "r402": {
    "endpoint": "https://fx402.xyz/rent/{mint}",
    "tiers": [
      { "id": "1d", "price": "0.25", "currency": "USDC", "chain": "solana" },
      { "id": "7d", "price": "1.00", "currency": "USDC", "chain": "solana" }
    ],
    "modes": ["view", "remix"],
    "facilitator": "https://facilitator.fx402.xyz/settle"
  }
}

🧠 Field Definitions

Field	Type	Description
`endpoint`	string	URL of the API endpoint that returns a full 402 requirements payload for this asset.
`tiers`	array	Optional summary of available pricing tiers. Should match the server response.
`modes`	array	Usage rights supported for this asset.
`facilitator`	string	Optional facilitator endpoint for automated verification.

⚙️ Discovery Rules

Clients should first check for an r402 object in the metadata.
If present, use its endpoint to request the full 402 payload.
If absent, assume the asset is not R402-compatible.
Marketplaces can cache tier summaries but must always refresh before payment.

🧩 Caching Guidelines

Metadata fields can be cached for up to 24 hours, but pricing should always be refreshed before rendering.
The endpoint field must be treated as canonical — it may change over time.
Clients should ignore unknown subfields for forward compatibility.

💡 Benefits

Enables NFT marketplaces to display prices and durations inline.
Removes the need for hardcoded pricing endpoints.
Allows wallets and agents to auto-generate “Rent” buttons directly from metadata.