polymerdao / evm-indexer

Multichain transfers squid

This squid captures USDC Transfer events on ETH and BSC, stores them in the same database and serves the data over a common GraphQL API.

The Ethereum processor is located in src/eth and similarly the Binance Chain processor can be found in src/bsc. The scripts file commands.json was updated with the commands process:eth and process:bsc to run the processors.

You can find some useful hints on developing multichain squids on the dedicated documentation page.

Dependencies: Node.js, Docker, Git.

Quickstart

# 0. Install @subsquid/cli a.k.a. the sqd command globally
npm i -g @subsquid/cli

# 1. Clone the repo
git clone https://github.com/subsquid-labs/multichain-transfers-example
cd multichain-transfers-example

# 2. Install dependencies
npm ci

# 3. Start a Postgres database container and detach
sqd up

# 4. Apply the migration
sqd migration:apply

# 5. Build the squid
sqd build

# 6. Run all services at once
sqd run .

A GraphiQL playground will be available at localhost:4350/graphql.

You can also run individual services separately:

sqd process:eth # Ethereum processor
sqd process:bsc # BSC processor
sqd serve       # GraphQL server

Database migration

After making a change to the graphql schema a migration needs to be generated.

npm run build
# apply existing migrations so that only new migrations are generated
npx squid-typeorm-migration apply
npx squid-typeorm-migration generate
npx squid-typeorm-migration apply

Troubleshooting

TypeError: Cannot read properties of undefined (reading 'toLowerCase')

    at /squid/node_modules/@subsquid/evm-processor/lib/processor.js:437:39
    at Array.map (<anonymous>)
    at mapRequest (/squid/node_modules/@subsquid/evm-processor/lib/processor.js:437:28)
    at EvmBatchProcessor.addLog (/squid/node_modules/@subsquid/evm-processor/lib/processor.js:195:20)
    at Object.<anonymous> (/squid/lib/chains/optimism.js:24:6)
    at Module._compile (node:internal/modules/cjs/loader:1364:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1422:10)
    at Module.load (node:internal/modules/cjs/loader:1203:32)

That is likely caused by missing some env vars like DISPATCHER_ADDRESS_BASE or UNIVERSAL_CHANNEL_ADDRESS_OPTIMISM. Check that you have all the required env vars set in your runtime.

Not ready to serve block N of dataset X

That error usually means that Subsquid's acrhival node is experiencing some issues. If you don't do a huge backfill, set the affected chain gateway like OPTIMISM_GATEWAY to an empty string and restart the indexer. Additionally, go to Subsquid's discord and open a support ticket like this one.

evm-indexer's Issues

Migrate indexer to 4-step handshake

Remove simclient specific tracking from indexer

Track fee vault internal txs

Migrate evm-indexer to subsquid

Integrate Juno with Polymer

Indexer not reporting relayer transactions

When querying the indexer for transactions on a virtual chain (not eth-sepolia==11155111) with no value transfer it is expected to see many recent relayer txns, however the most recent returned record is showing a block timestamp of 7/29 (1722269380). Health checks and loadtest have been going since then so relayer txns have been occurring.

RELAYER_ADDRESS_BASE --> 0xc760fbfa7e80564052a2e50976450884f5cc41af
RELAYER_ADDRESS_OPTIMISM --> 0xc760fbfa7e80564052a2e50976450884f5cc41af

query MyQuery {
  transactions(limit: 100, where: {value_eq: "0", chainId_not_eq: 11155111}, orderBy: blockTimestamp_DESC) {
    gasPrice
    gasUsed
    chainId
    blockTimestamp
  }
}

{
  "data": {
    "transactions": [
      {
        "gasPrice": "1593106",
        "gasUsed": "30207",
        "chainId": 11155420,
        "blockTimestamp": "1722269380000"
      },
      {
        "gasPrice": "5246581123",
        "gasUsed": "30207",
        "chainId": 11155420,
        "blockTimestamp": "1722178586000"
      },
      {
        "gasPrice": "1000499",
        "gasUsed": "685936",
        "chainId": 84532,
        "blockTimestamp": "1720092820000"
      },
      {
        "gasPrice": "1000525",
        "gasUsed": "687437",
        "chainId": 84532,
        "blockTimestamp": "1720092566000"
      },
      {
        "gasPrice": "33905177",
        "gasUsed": "685936",
        "chainId": 11155420,
        "blockTimestamp": "1720092558000"
      },
      {
...

Track FeeVault contract txs

Index fee events

evm-indexer restarts when RPC endpoint is not available

It seems that ponder restarts when an RPC provider does not respond. This temporarily halts the indexer service. Ideally we should have a more graceful response to an RPC endpoint being unreachable.

Backfill polymer gas metrics

Fix Juno outstanding issues

• A frequent error log in prod: pq: unsupported Unicode escape sequence
• Some blocks are missing - might be caused by the above bug
• Try to backfill again to see if the removal of isCosmosSdk affected Juno