@dcl/urn-resolver

A TypeScript library that resolves and parses Decentraland asset URNs (Uniform Resource Names) within the urn:decentraland namespace, following the definitions outlined in the common-metaverse/urn-namespaces repository. It supports both on-chain and off-chain assets, such as LAND, wearables, and collections.

Table of Contents

• Features
• Dependencies & Related Services
• Getting Started
  • Prerequisites
  • Installation
• Usage
  • Parsing URNs
  • Resolving Content URLs
• Registered Routes
• Return Types
• Testing
• Contributing

Features

• URN Parsing: Parse URNs for on-chain assets (LAND parcels, NFT wearables, collections v1/v2)
• Off-chain Support: Parse URNs for off-chain assets (base wearables, third-party collections)
• Component Resolution: Resolve URN components (network, contract address, token ID, coordinates)
• Query Parameters: Support for query parameters in URNs (e.g., ?atBlock=123456)
• Content URL Resolution: Resolve URNs to content server URLs
• TypeScript Types: Provides type-safe structures for all parsed URN results
• Standards Compliant: Follows URN namespace definitions from common-metaverse/urn-namespaces

Dependencies & Related Services

This library has no external service dependencies. It is a pure parsing library that can be used offline.

Getting Started

Prerequisites

• Node.js: >=22.0.0
• pnpm: For package management

Installation

pnpm add @dcl/urn-resolver

Usage

Parsing URNs

Use the parseUrn function to parse a Decentraland URN into a structured object:

import { parseUrn } from '@dcl/urn-resolver'

const parsed = await parseUrn('urn:decentraland:sepolia:LAND:-10,-13?atBlock=151231111')
/*
{
  uri: URL {
    href: 'urn:decentraland:sepolia:LAND:-10,-13?atBlock=151231111',
    protocol: 'urn:',
    pathname: 'decentraland:sepolia:LAND:-10,-13',
    search: '?atBlock=151231111',
    searchParams: URLSearchParams { 'atBlock' => '151231111' }
  },
  blockchain: 'ethereum',
  type: 'blockchain-asset',
  network: 'sepolia',
  contractAddress: '0x7a73483784ab79257bb11b96fd62a2c3ae4fb75b',
  id: '0xfffffffffffffffffffffffffffffff6fffffffffffffffffffffffffffffff3',
  x: -10,
  y: -13
}
*/

Resolving Content URLs

Use the resolveUrlFromUrn function to resolve a URN to a content server URL:

import { resolveUrlFromUrn } from '@dcl/urn-resolver'

const url = await resolveUrlFromUrn('urn:decentraland:matic:collections-v2:0x....:1')
// Returns the content URL where the asset can be fetched

Utility Functions

import { LandUtils, isExtendedUrn, getTokenIdAndAssetUrn } from '@dcl/urn-resolver'

// Check if a URN is an extended URN (includes tokenId)
const isExtended = isExtendedUrn('urn:decentraland:matic:collections-v2:0x...:1:123')

// Extract tokenId and asset URN from an extended URN
const { tokenId, assetUrn } = getTokenIdAndAssetUrn('urn:decentraland:matic:collections-v2:0x...:1:123')

Registered Routes

The library supports the following URN patterns:

| Pattern | Description | | ------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------- | | decentraland:off-chain:{registry}:{name} | Resolve static offchain assets (i.e. base wearables, not in any blockchain) | | decentraland:{network}:collections-v1:{contract(0x[a-fA-F0-9]+)}:{name} | Resolve an ethereum wearables collection asset by contract address (v1) | | decentraland:{network}:collections-v1:{contract(0x[a-fA-F0-9]+)}:{name}:{tokenId} | Resolve an ethereum wearable item from collections v1 by contract address and token id | | decentraland:{network}:collections-v1:{collection-name}:{name} | Resolve an ethereum wearables collection asset by collection name (wearables API) (v1) | | decentraland:{network}:collections-v1:{collection-name}:{name}:{tokenId} | Resolve an ethereum wearable item from collections v1 by collection name and token id | | decentraland:{network}:collections-v2:{contract(0x[a-fA-F0-9]+)}:{id} | Resolve an ethereum wearables collection asset by contract address (v2) | | decentraland:{network}:collections-v2:{contract(0x[a-fA-F0-9]+)}:{id}:{tokenId} | Resolve an ethereum wearable item from collections v2 by contract address and token id | | decentraland:{network}:LAND:{x},{y} | Resolves the ethereum asset of a LAND position | | decentraland:{network}:LAND:{tokenId} | Resolves the ethereum asset of a LAND by tokenId | | decentraland:{network}:collections-thirdparty:{thirdPartyName} | Resolves the ethereum asset of a third party provider (polygon only) | | decentraland:{network}:collections-thirdparty:{thirdPartyName}:{collectionId} | Resolves the ethereum asset of a third party collection (polygon only) | | decentraland:{network}:collections-thirdparty:{thirdPartyName}:{collectionId}:{itemId} | Resolves the ethereum asset of a third party collection asset (polygon only) | | decentraland:{network}:collections-thirdparty:{thirdPartyName}:{collectionId}:{itemId}:{nftChain}:{nftContractAddress}:{nftTokenId} | Resolves the ethereum asset of a third party collection item (polygon only) |

Return Types

The parseUrn function returns a DecentralandAssetIdentifier union type. All possible return types are defined in src/types.ts:

• BlockchainAsset - Generic blockchain asset
• BlockchainLandAsset - LAND parcel with x,y coordinates
• BlockchainCollectionV1 - Collections v1 collection
• BlockchainCollectionV1Asset - Collections v1 asset (wearable definition)
• BlockchainCollectionV1Item - Collections v1 item (NFT instance)
• BlockchainCollectionV2 - Collections v2 collection
• BlockchainCollectionV2Asset - Collections v2 asset (wearable definition)
• BlockchainCollectionV2Item - Collections v2 item (NFT instance)
• BlockchainCollectionThirdPartyName - Third party provider
• BlockchainCollectionThirdPartyCollection - Third party collection
• BlockchainCollectionThirdParty - Third party asset
• BlockchainCollectionThirdPartyItem - Third party item (linked wearable)
• OffChainAsset - Off-chain asset (base wearables)
• EntityV3Asset - Entity with IPFS CID

Testing

Run all tests:

pnpm --filter @dcl/urn-resolver test

Test Structure

Tests are located in the test/ directory:

test/
  collection-items-utils.spec.ts
  land-utils.spec.ts
  parse-urn.spec.ts
  resolve-url-from-urn.spec.ts

Contributing

We welcome contributions! Follow the steps below to set up the project for development.

Prerequisites

You will need to install jq. If you are using MacOS you can install it by running:

brew install jq

Build

The library is built with Node.js 22.x from the monorepo root.

pnpm install
pnpm --filter @dcl/urn-resolver build

AI Agent Context

For detailed AI Agent context, see docs/ai-agent-context.md.