Metis The Graph Template

This is a template for creating a custom subgraph for Metis contracts. Follow this guide to create and deploy your own subgraph.

Prerequisites

• Node.js version 20 (as specified in .nvmrc)
• Yarn package manager
• A deployed smart contract on Metis network (follow the docs)

Step-by-Step Guide

1. Create a Subgraph in The Graph Studio

1. Go to The Graph Studio
2. Connect your wallet
3. Click "Create a Subgraph"
4. Name your subgraph (e.g., "My Metis Subgraph")
5. Note down the deployment key provided

2. Install Dependencies

# Install project dependencies
yarn install

3. Add Contract ABIs

Add your contract ABIs as JSON files in the abis directory and delete redundant files. For example:

# Example: Copy your contract ABI to the abis directory
cp path/to/your/contract.json ./abis/
rm ./abis/StakeAndLock.json

4. Update Schema

1. Open schema.graphql
2. Define your entities based on the data you want to index
3. Each entity should have:
   • Required fields (ID, timestamps)
   • Fields matching your contract events
   • Proper relationships between entities

Example:

type Entity @entity {
  id: ID!
  field1: String!
  field2: BigInt!
  timestamp: BigInt!
}

5. Update Subgraph Configuration (subgraph.yaml)

1. Open subgraph.yaml
2. Update the following fields:
   • dataSources[].source.address: Your contract address
   • dataSources[].source.abi: Your contract ABI name
   • dataSources[].source.startBlock: The block number where your contract was deployed
   • dataSources[].mapping.entities: Your defined entities from schema.graphql
   • dataSources[].mapping.abis[].name: Your contract ABI name
   • dataSources[].mapping.abis[].file: Path to your ABI file
   • dataSources[].mapping.eventHandlers: Events you want to index and their handlers

Example configuration:

dataSources:
  - kind: ethereum
    name: YourContract
    network: andromeda
    source:
      address: "0x..." # Your contract address
      abi: YourContract # Your contract ABI name
      startBlock: 12345678 # Your contract deployment block
    mapping:
      entities:
        - YourEntity
      abis:
        - name: YourContract
          file: ./abis/YourContract.json
      eventHandlers:
        - event: YourEvent(indexed uint256,address)
          handler: handleYourEvent

6. Update Mappings (mapping.ts)

1. Open mapping.ts
2. Implement event handlers for each event you want to index
3. Create/update entities based on event data
4. Save entities using entity.save()

Example:

export function handleEvent(event: Event): void {
  let entity = new Entity(event.transaction.hash.toHex())
  entity.field1 = event.params.value
  entity.timestamp = event.block.timestamp
  entity.save()
}

Note: every time you update the schema or the events or the subgraph configuration, you need to run yarn codegen to update the types.

7. Update Package Configuration

1. Open package.json
2. Update the name field to match your subgraph name
3. Update any other relevant fields

8. Build and Deploy

yarn codegen
yarn build

Authenticate with The Graph Studio and cli will prompt you to paste the deployment key:

yarn auth

Deploy the subgraph:

yarn deploy

Testing Your Subgraph

1. Go to The Graph Studio
2. Select your subgraph
3. Use the GraphQL playground to test queries
4. Check the logs for any indexing issues

Common Issues and Solutions

• If you get ABI errors, ensure your ABI file is valid JSON
• If events aren't being indexed, verify the event names match exactly
• If entities aren't saving, check your mapping logic and entity definitions

Resources

• The Graph Documentation
• AssemblyScript Documentation
• GraphQL Documentation