Subgraph Builder

WHAT IT DOES

Subgraph Builder lets you generate a complete The Graph subgraph configuration from a contract address and event signatures. You provide the contract address, one or more event signatures, a subgraph name, and an entity name, and the tool generates the essential files: subgraph.yaml (manifest), schema.graphql (data model), and a mapping template (AssemblyScript) with event handlers. It reads the current network chain ID from your wallet provider to set the correct network in the manifest. This is the fastest way to scaffold a subgraph for indexing your contract's events, saving hours of manual file setup and boilerplate coding.

HOW TO USE

Connect your wallet using the "Connect" button (required for network detection). Select the target network (Ethereum Mainnet, Sepolia, Polygon, BSC, Arbitrum, Optimism, and testnets are supported). Enter a subgraph name, the contract address, one or more event signatures (one per line), and an entity name. Click "Build subgraph" — the tool generates the configuration files. You can download each file individually using the download buttons. The entire operation is read-only — no transactions are signed or sent. After generation, you can review the files, copy them into your subgraph project, and deploy to The Graph using the Graph CLI.

TECHNICAL MECHANISM

The tool uses ethers.js to parse the event signatures and build an ABI interface. It generates a schema.graphql file with an entity that includes standard fields (id, blockNumber, transactionHash, eventName) plus fields for each event parameter, with Solidity types mapped to GraphQL types (e.g., address → Bytes, uint256 → BigInt, bool → Boolean). The subgraph.yaml manifest is built with the correct network, contract address, ABI reference, and event handlers for each signature. The mapping template is generated with placeholder AssemblyScript code that creates a new entity for each event and assigns the event parameters to entity fields. The tool does not deploy the subgraph — it only generates the scaffolding files that you can customize and deploy.

WHAT IT CANNOT SEE

The tool cannot verify the correctness of the ABI or event signatures — incorrect signatures will produce invalid schema or handlers. It cannot validate that the generated subgraph will compile or sync correctly without manual review. It cannot handle complex nested types or dynamic arrays reliably without full ABI parsing (e.g., arrays of structs, nested tuples). It is limited by RPC provider rate limits and eth_getLogs block range caps, though the tool does not fetch logs for generation. It cannot generate subgraphs for non-EVM chains. It cannot deploy the subgraph to The Graph's hosted service or Studio — only generates the configuration files. It cannot detect events from non-indexed parameters efficiently.

PLEASE NOTE

This tool is for scaffolding and educational purposes. Always review the generated files and test your subgraph locally before deploying to production. The generated code may require manual adjustments for complex event types or custom logic. The tool does not persist any data; all state is lost on page reload. EVM chains only.