LP-0036Finalgraphg-chaingraphqlindexingsubgraph

LP-036: Graph VM

Abstract

The Graph VM runs the G-chain, a purpose-built chain for indexing and querying on-chain data across all Lux chains. Developers deploy subgraph manifests as G-chain transactions. The VM indexes events from source chains (received via Warp messages), builds queryable data stores, and exposes GraphQL endpoints. The G-chain is the native indexing layer -- no external indexing infrastructure required.

Specification

Subgraph Deployment

A subgraph manifest is deployed as a G-chain transaction:


SubgraphManifest {
    name            string
    version         string
    sourceChainIDs  [][32]byte   // chains to index
    dataSources     []DataSource
    schema          string       // GraphQL SDL schema
    mappings        []byte       // WASM mapping handlers (AssemblyScript compiled)
}

DataSource {
    chainID     [32]byte
    address     address         // contract address to watch
    startBlock  uint64
    eventABI    []byte          // ABI of events to index
}

Indexing Pipeline

1. Event ingestion: Warp messages from source chains deliver event logs to the G-chain

2. Mapping execution: WASM handlers process events and produce entity updates

3. Storage: entities are stored in the G-chain's native key-value store

4. Query: GraphQL queries are resolved against the entity store

The VM executes WASM handlers in a sandboxed environment with metered gas. Handlers can read entity state but not make external calls.

Query Interface

Each subgraph exposes a GraphQL endpoint:


POST /ext/bc/{gchain-blockchain-id}/subgraphs/name/{subgraph-name}/graphql
{
    "query": "{ tokens(first: 10, orderBy: totalSupply) { id name totalSupply } }"
}

Queries are read-only and do not consume gas. Query rate limiting is enforced per client IP.

Cross-Chain Indexing

The G-chain indexes all Lux chains simultaneously:

C-chain EVM events (Transfer, Swap, etc.)
L1 / L2 chain events (Zoo, Hanzo, SPC, Pars; per LP-018)
P-chain staking events
X-chain asset operations

Source chain events are delivered via Warp messages with guaranteed ordering per source chain.

Subgraph Governance

Deployment fee: 10 LUX per subgraph deployment (prevents spam)
Curation: users can stake LUX on subgraphs they find useful, earning query fee share
Deprecation: subgraph owners can deprecate, stopping indexing and freeing resources

Security Considerations

1. WASM sandboxing: mapping handlers run in a metered WASM VM with no host access. Infinite loops are terminated by gas limits.

2. Query DoS: complex queries are bounded by a query complexity limit (max 1000 entity fetches per query).

3. Data integrity: indexed data is derived deterministically from source chain events. Any G-chain validator can verify by re-executing mappings.

Reference

| Resource | Location |

|---|---|

| Graph VM | github.com/luxfi/node/vms/graphvm/ |

| WASM runtime | github.com/luxfi/node/vms/graphvm/wasm/ |

| Warp event delivery | LP-021 |

Copyright

Licensed under the MIT License.