Docs

Technical documentation, guidelines, and protocol specifications for Medialane.

Protocol Specification

The Medialane protocol consists of two on-chain contracts on Starknet mainnet and an off-chain indexer/API layer. This document describes the contracts, their interfaces, and the event model used by the indexer.

Contracts (Starknet Mainnet)

Marketplace Contract

0x059deafbbafbf7051c315cf75a94b03c5547892bc0c6dfa36d7ac7290d4cc33a

Handles order creation, fulfillment, cancellation, and royalty distribution.

Collection Registry Contract

0x05e73b7be06d82beeb390a0e0d655f2c9e7cf519658e04f05d9c690ccc41da03

Factory for deploying IP NFT collections and registry for on-chain collection IDs.

NFT Standard

Medialane collections implement SNIP-2, the Starknet equivalent of ERC-721. Each token has a unique token_id (u256) and a token_uri returning a ByteArray pointing to IPFS metadata.

The metadata JSON conforms to the OpenSea/ERC-721 metadata standard with Medialane-specific extensions for licensing attributes (see below).

Metadata Schema

{
  "name": "My IP Asset",
  "description": "A description of the work.",
  "image": "ipfs://bafybei...",
  "attributes": [
    { "trait_type": "IP Type",          "value": "Visual Art" },
    { "trait_type": "License",          "value": "CC BY-NC-SA 4.0" },
    { "trait_type": "Commercial Use",   "value": "Not Allowed" },
    { "trait_type": "Derivatives",      "value": "Allowed with Attribution" },
    { "trait_type": "AI Training",      "value": "Not Allowed" },
    { "trait_type": "Geographic Scope", "value": "Worldwide" },
    { "trait_type": "Royalty %",        "value": "10" }
  ]
}

SNIP-12 Typed Data (Order Signing)

All marketplace intents (listings, offers, fulfillments, cancellations) use SNIP-12 typed data for off-chain signing. The domain separator is:

{
  "name": "Medialane",
  "version": "1",
  "revision": "1",
  "chainId": "SN_MAIN"
}

The indexer validates submitted signatures on-chain before recording orders. Fulfilled and cancelled orders are reconciled from on-chain events emitted by the marketplace contract.

Marketplace Events

The marketplace contract emits the following events, indexed by the Medialane mirror:

OrderCreated

Emitted when a listing or offer intent is submitted. Contains order_hash only — full params fetched via get_order_details().

OrderFulfilled

Emitted when a buyer executes a listing or a creator accepts an offer.

OrderCancelled

Emitted when an order is cancelled by the maker.

Collection Registry Events

CollectionCreated

Emitted when a new collection is deployed through the factory. Data contains collection_id (u256 low/high), owner address, and name/symbol/base_uri ByteArrays. The actual ERC-721 contract address (ip_nft) is resolved by calling get_collection(collection_id)on the registry.

Indexer Architecture

The Medialane off-chain layer consists of three components running as a single Bun process:

Mirror — polls the Starknet RPC for new blocks, processes events, and writes to PostgreSQL
Orchestrator — an in-memory worker that processes metadata fetch jobs (IPFS resolution, stats updates)
API — a Hono REST server exposing all platform data to frontends and third-party integrations

The indexer polls every ~6 seconds. Block lag is typically 1–3 blocks. New collections and order events appear in the API within one indexer tick of the transaction being confirmed.