rETH Transfers (No-Code)

This example indexes Transfer events from the Rocket Pool rETH token contract using a YAML config — no Python required.

Source: examples/reth_transfer_nocode/

Run

cd examples/reth_transfer_nocode
cp .env.example .env
# Fill PROVIDER_URL and HYPERSYNC_BEARER_TOKEN in .env
tiders start

What it does

1. Queries logs matching the Transfer event from the rETH contract via HyperSync
2. Decodes the raw log data into typed from, to, and amount columns
3. Casts decimal256 to decimal128, unnecessary for PyArrow dataset (Parquet), but include if writer doesn’t support decimal256 values
4. Hex-encodes binary fields for readability
5. Joins decoded transfer data with block timestamps via SQL step, so the transfer table include a timestamp
6. Writes to a PyArrow dataset

Full config

project:
  name: rETH_transfer
  description: Index rETH Transfer events from the Rocket Pool rETH token contract.
  repository: https://github.com/yulesa/tiders/example/reth_transfer_nocode

provider:
  kind: hypersync
  url: ${PROVIDER_URL}
  bearer_token: ${HYPERSYNC_BEARER_TOKEN}

contracts:
  - name: RocketTokenRETH
    address: 0xae78736Cd615f374D3085123A210448E74Fc6393
    abi: ./RocketTokenRETH.abi.json

query:
  kind: evm
  from_block: 13325304
  to_block: 13325404
  logs:
    - address: RocketTokenRETH.address
      topic0: "Transfer(address,address,uint256)"
      include_blocks: true
  fields:
    log: [address, topic0, topic1, topic2, topic3, data, block_number, transaction_hash, log_index]
    block: [number, timestamp]

steps:
  - kind: evm_decode_events
    config:
      event_signature: "Transfer(address indexed from, address indexed to, uint256 amount)"
      output_table: transfers
      allow_decode_fail: true

  - kind: cast_by_type
    name: i256_to_i128
    config:
      from_type: "decimal256(76,0)"
      to_type: "decimal128(38,0)"
      allow_cast_fail: true

  - kind: hex_encode

  - kind: sql
    config:
      queries:
        - >
          CREATE OR REPLACE TABLE transfers AS
          SELECT transfers.*, blocks.timestamp AS block_timestamp
          FROM transfers
          INNER JOIN blocks ON blocks.number = transfers.block_number

writer:
  kind: pyarrow_dataset
  config:
    base_dir: data/pyarrow

Key concepts

Contract references — the contracts: section loads RocketTokenRETH.abi.json and makes the contract available by name. topic0: "Transfer(address,address,uint256)" is a human-readable event signature; the CLI converts it to a Keccak-256 hash automatically.

Decode step — evm_decode_events reads the raw topic1, topic2, and data columns and produces typed from, to, and amount columns in a new transfers table.

Cast step — EVM uint256 values are decoded as decimal256(76,0). The cast_by_type step downcasts them to decimal128(38,0). This is step is dispensable in PyArrow datasets (Parquet), but necessary in databases that don’t support decimal256(76,0).

SQL step — the sql step runs DataFusion SQL against the in-memory tables. Both transfers and blocks are available because include_blocks: true was set on the log request.

Environment variables — credentials stay in .env and are referenced as ${PROVIDER_URL} in the YAML. The CLI loads .env automatically from the config directory.