Docs

eth_getFilterLogs - World Chain RPC Method

Returns all logs matching a previously created filter on World Chain. Essential for initial log retrieval, backfilling event data, and one-time historical queries for human-verified DeFi, identity-gated applications, bot-resistant services.

Returns an array of all logs matching the filter that was previously created with eth_newFilter on World Chain. Unlike eth_getFilterChanges which returns only new logs since the last poll, this method returns the complete set of matching logs for the filter's block range.

Why World Chain? Build on the human-first Ethereum L2 powered by World ID with World ID integration for free gas and priority blockspace.

When to Use This Method

eth_getFilterLogs is essential for World Chain developers building sybil-resistant applications:

  • Initial Log Retrieval — Fetch the complete set of matching logs when you first create a filter on World Chain
  • Backfilling Event Data — Recover historical events after an indexer restart or gap in polling
  • One-Time Queries — Retrieve all logs for a specific block range without incremental polling
  • Data Reconciliation — Compare against incrementally collected data from eth_getFilterChanges to detect missed events

Code Examples

Common Use Cases

1. Backfill Event Data After Indexer Restart

Recover missed events when your indexer goes down and comes back:

JavaScript
async function backfillEvents(provider, contractAddress, topics, lastProcessedBlock) {
  const currentBlock = await provider.getBlockNumber();

  // Create a filter covering the gap
  const filterId = await provider.send('eth_newFilter', [{
    fromBlock: '0x' + (lastProcessedBlock + 1).toString(16),
    toBlock: '0x' + currentBlock.toString(16),
    address: contractAddress,
    topics: topics
  }]);

  // Retrieve all logs in the gap
  const logs = await provider.send('eth_getFilterLogs', [filterId]);
  console.log(`Backfilling ${logs.length} events from blocks ${lastProcessedBlock + 1} to ${currentBlock}`);

  for (const log of logs) {
    await processEvent(log);
  }

  // Clean up and switch to incremental polling
  await provider.send('eth_uninstallFilter', [filterId]);
  return currentBlock;
}

2. Compare Filter Results with Direct Query

Verify data consistency between filter-based and direct log queries:

JavaScript
async function verifyFilterResults(provider, filterParams) {
  // Create filter and get logs via eth_getFilterLogs
  const filterId = await provider.send('eth_newFilter', [filterParams]);
  const filterLogs = await provider.send('eth_getFilterLogs', [filterId]);

  // Get logs directly via eth_getLogs
  const directLogs = await provider.send('eth_getLogs', [filterParams]);

  console.log(`Filter logs: ${filterLogs.length}, Direct logs: ${directLogs.length}`);

  if (filterLogs.length !== directLogs.length) {
    console.warn('Mismatch detected — investigate missing events');
  }

  await provider.send('eth_uninstallFilter', [filterId]);
  return { filterLogs, directLogs };
}

3. Paginated Historical Event Loader

Load large volumes of historical events in manageable chunks:

JavaScript
async function loadHistoricalEvents(provider, contractAddress, startBlock, endBlock, chunkSize = 2000) {
  const allLogs = [];

  for (let from = startBlock; from <= endBlock; from += chunkSize) {
    const to = Math.min(from + chunkSize - 1, endBlock);

    const filterId = await provider.send('eth_newFilter', [{
      fromBlock: '0x' + from.toString(16),
      toBlock: '0x' + to.toString(16),
      address: contractAddress
    }]);

    const logs = await provider.send('eth_getFilterLogs', [filterId]);
    allLogs.push(...logs);

    console.log(`Blocks ${from}-${to}: ${logs.length} events (total: ${allLogs.length})`);

    await provider.send('eth_uninstallFilter', [filterId]);
  }

  return allLogs;
}

Error Handling

Common errors and solutions:

Error CodeDescriptionSolution
-32000Filter not foundFilter expired or was uninstalled — recreate with eth_newFilter
-32000Query returned more than 10000 resultsNarrow the block range in your filter — use smaller fromBlock/toBlock windows
-32600Invalid requestVerify the filter ID is a valid hex string
-32603Internal errorNode may be overloaded — retry with exponential backoff
-32005Rate limit exceededReduce request frequency or implement client-side rate limiting
JavaScript
async function safeGetFilterLogs(provider, filterId, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await provider.send('eth_getFilterLogs', [filterId]);
    } catch (error) {
      if (error.message.includes('filter not found')) {
        throw new Error('Filter expired — must recreate before retrying');
      }
      if (error.message.includes('more than 10000 results')) {
        throw new Error('Too many results — narrow your block range');
      }
      if (i < maxRetries - 1) {
        const delay = Math.pow(2, i) * 1000;
        await new Promise(r => setTimeout(r, delay));
      } else {
        throw error;
      }
    }
  }
}