The Lambdas v2 (lamb2) service is a modern implementation that replaces the legacy lambdas service bundle associated with Catalyst nodes. This service provides a comprehensive API for interacting with Catalyst Content Servers, enabling Decentraland clients to resolve entities, validate asset ownership, query user profiles, and access blockchain-based NFT data across the Decentraland ecosystem.

This server interacts with Catalyst Content Servers, The Graph subgraphs, blockchain smart contracts, and third-party NFT providers to deliver real-time information about user assets, profiles, and Decentraland world configurations.

• Features
• Dependencies & Related Services
• API Documentation
• Getting Started
  • Prerequisites
  • Installation
  • Configuration
  • Running the Service
• Testing
• AI Agent Context

• User Assets: Retrieve wearables, emotes, names, and lands owned by Ethereum addresses with filtering and pagination support
• Profile Management: Fetch and manage user profiles with support for avatar configurations and versioning
• Ownership Validation: Verify ownership of wearables, emotes, names, and other Decentraland assets using blockchain data
• Third-Party Integrations: Support for third-party wearables and collections with real-time NFT ownership validation
• NFT Collections: Query all available NFT collections across Ethereum mainnet (L1) and Polygon (L2) networks
• Entity Resolution: Resolve entity metadata and content files from Catalyst Content Servers for client consumption
• Contract Data: Access Catalyst servers list from DAO, Points of Interest (POIs), and name denylists from smart contracts
• Outfit Queries: Retrieve outfit configurations and validate ownership of outfit components
• Parcel Permissions: Query parcel operators and permissions for Decentraland LAND parcels
• Explorer Endpoints: Specialized endpoints for Decentraland Explorer client with combined asset queries
• Smart Caching: LRU cache implementation for improved performance on blockchain and API queries

This service interacts with the following services:

• Catalyst Content Server: Fetches entity data, wearable definitions, and content files for Decentraland assets
• Catalyst Owner: Deployment bundle that incorporates lamb2 as part of the complete Catalyst node stack
• Marketplace API: Primary data source for NFT collections, wearables, emotes, and names with enhanced metadata
• The Graph Subgraphs: Blockchain indexing service for ownership verification across multiple subgraphs:
  • Ethereum Collections Subgraph (L1 wearables/emotes)
  • Polygon Collections Subgraph (L2 wearables/emotes)
  • ENS Subgraph (Decentraland name ownership)
  • Third-Party Registry Subgraph (third-party collections)
  • Land Manager Subgraph (LAND and Estate ownership)
• Ethereum RPC: Connects to Ethereum mainnet or Sepolia via https://rpc.decentraland.org for smart contract queries
• Polygon RPC: Connects to Polygon mainnet or Amoy via https://rpc.decentraland.org for L2 smart contract queries
• NFT Worker (Alchemy): Third-party NFT ownership validation service at https://nfts.decentraland.org
• Catalyst DAO Contract: Retrieves approved Catalyst servers list from the DAO on Ethereum mainnet
• POI Contract: Fetches Points of Interest from Polygon network
• Name Denylist Contract: Retrieves denied names from Ethereum mainnet

The API is fully documented using the OpenAPI standard. Its schema is located at docs/openapi.yaml.

Before running this service, ensure you have the following installed:

• Node.js: Version 18.x or higher (LTS recommended)
• Yarn: Version 1.22.x or higher

1. Clone the repository:

git clone https://github.com/decentraland/lamb2.git cd lamb2

2. Install dependencies:

yarn install

3. Build the project:

yarn build

The service uses environment variables for configuration. Create a .env file in the root directory containing the environment variables for the service to run. Use the .env.default variables as an example.

The Lambdas v2 service is a lightweight, stateless service that does not require local databases or message brokers. Unlike many backend services, it can run standalone with minimal setup.

To run the service in development mode:

yarn build yarn start

This service includes comprehensive test coverage with both unit and integration tests.

Run all tests with coverage:

yarn test

Run tests in watch mode:

yarn test --watch

Run only unit tests:

yarn test test/unit

Run only integration tests:

yarn test test/integration

• Unit Tests (test/unit/): Test individual components and functions in isolation
• Integration Tests (test/integration/): Test the complete request/response cycle with mocked external dependencies

For detailed testing guidelines and standards, refer to our Testing Standards documentation.

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