Light Curate Integration

Developer guide for integrating with Kleros Light Curate (V1 with subgraph-based storage)

Light Curate: Integration for Devs

This covers Light Curate (V1). For V2 Curate, see the Developers Curate section.

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Overview

Light Curate significantly decreases deployment and operation costs compared to Curate Classic by changing the data storage strategy:

• Item data is NOT stored in contract storage. Only the IPFS multihash is stored on-chain. Storage cost is O(1) instead of O(n).
• Item fields are stored in the subgraph via The Graph’s IPFS API. No need for @kleros/gtcr-encoder.
• Uses EIP-1167 minimal proxy for deployments. Deployment cost dropped from ~7M gas to ~700K gas.

Tradeoff: other contracts cannot query the TCR for field values on-chain (only the IPFS hash is available).

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Reading Data

Fetching Items via Subgraph

Light Curate uses litems entities (prefixed with l). Pass the TCR address to filter:

{
  litems(
    first: 10
    where: {
      status: Registered
      registryAddress: "0xYOUR_LIST_ADDRESS_LOWERCASE"
    }
    orderBy: latestRequestResolutionTime
    orderDirection: desc
  ) {
    itemID
    data
    props {
      type
      label
      description
      value
    }
  }
}

The props field contains decoded item fields directly. No encoder library needed.

Fetching a Specific Item

Item entities have IDs in the format <itemID>@<listAddress>:

const compoundId = `${itemID}@${tcrAddress.toLowerCase()}`;
const result = useQuery(ITEM_DETAILS_QUERY, { variables: { id: compoundId } });

View Contract

A view contract is available for fetching all relevant info in a single call.

Gnosis Chain deployment: 0x08e58Bc26CFB0d346bABD253A1799866F269805a

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Writing Data

Submitting an Item

1. Upload item data to IPFS (use both The Graph’s IPFS endpoint and Kleros IPFS node)
2. Call addItem() on the LightGeneralizedTCR contract with the IPFS URI and required deposit

REACT_APP_IPFS_GATEWAY=https://cdn.kleros.link
REACT_APP_HOSTED_GRAPH_IPFS_ENDPOINT=https://api.thegraph.com/ipfs

Pin data to IPFS nodes you control in addition to The Graph’s and Kleros’ nodes.

Challenging and Executing Requests

• Challenge: call challengeRequest() with a deposit
• Execute: call executeRequest() after the challenge period passes unchallenged

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Subgraph Conventions

Entity Prefix	Version
litems, lrequests, etc.	Light Curate
items, requests, etc.	Curate Classic

Addresses must be lowercase in queries. The subgraph does not understand checksummed addresses.

The hosted service has a 1000 item limit per query. For larger registries, paginate using skip or id_gt.

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Subgraph Deployment

If you deployed a list using the factory, it already has a subgraph deployed and available. For custom deployments, see The Graph documentation.

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Resources

Light Curate Contracts

Source code

Query Examples

More GraphQL query examples