eth_getLogs | Centrifuge RPC Docs

Query and filter event logs from smart contracts on Centrifuge Mainnet. Essential for tracking events, monitoring contracts, and building event-driven applications.

Returns an array of all logs matching a given filter object. Essential for querying historical events and monitoring smart contract activity.

Block Range Limits

Plan	Maximum blocks per request
Free	Not available
Developer	500
Growth	10,000
Scale and above	10,000

Both endpoints count toward the limit: toBlock - fromBlock + 1. Supply explicit numeric bounds for historical ranges, or use blockHash for one block. Split longer ranges into requests within your plan limit. See request rules and errors, including accepted block tags.

When to Use This Method

eth_getLogs is crucial for:

Event Monitoring - Track smart contract events and state changes
Historical Queries - Search past events within a block range
DeFi Analytics - Monitor trades, liquidity events, and protocol activity
Indexing - Build databases of on-chain events

Implementation Examples

The helpers below take a numeric starting height and a numeric ending height or latest. They resolve latest once and split historical ranges into 500-block requests. The JavaScript examples use toQuantity to encode block heights without leading zeroes.

Advanced Usage

Multiple Address Filtering

JSON

{
  "jsonrpc": "2.0",
  "method": "eth_getLogs",
  "params": [{
    "fromBlock": "0x1",
    "toBlock": "0xc8",
    "address": [
      "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
      "0x4200000000000000000000000000000000000006"
    ],
    "topics": [
      "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
    ]
  }],
  "id": 1
}

Topic Filtering with OR Logic

JSON

{
  "jsonrpc": "2.0",
  "method": "eth_getLogs",
  "params": [{
    "fromBlock": "0x1",
    "toBlock": "0xc8",
    "topics": [
      [
        "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
        "0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925"
      ]
    ]
  }],
  "id": 1
}

Notes

Centrifuge supports historical log queries back to genesis block
Query limits: Maximum 10,000 results per request
Block range limits: Developer 500; Growth, Scale, and Enterprise 10,000 blocks per request
Topic arrays: Support up to 4 topics with OR logic within each position
Performance tip: Use specific address filters to improve query speed
Event signatures: First topic is always the keccak256 hash of the event signature

Common Use Cases

1. Token Balance History

JavaScript

// Track historical token balance changes
async function getBalanceHistory(tokenAddress, userAddress, fromBlock) {
  const monitor = new EventMonitor(provider);
  
  // Get all transfers involving the user
  const logs = await monitor.getFilteredTransfers(
    tokenAddress,
    userAddress,
    'both',
    fromBlock,
    'latest'
  );
  
  // Calculate balance changes
  const balanceChanges = [];
  let currentBalance = 0n;
  
  for (const log of logs) {
    const iface = new Interface([
      'event Transfer(address indexed from, address indexed to, uint256 value)'
    ]);
    
    const decoded = iface.parseLog({
      topics: log.topics,
      data: log.data
    });
    
    const change = decoded.args.from.toLowerCase() === userAddress.toLowerCase() ?
      -decoded.args.value : decoded.args.value;
    
    currentBalance += change;
    
    balanceChanges.push({
      blockNumber: log.blockNumber,
      transactionHash: log.transactionHash,
      change: change.toString(),
      balance: currentBalance.toString(),
      type: change < 0 ? 'outgoing' : 'incoming'
    });
  }
  
  return balanceChanges;
}

2. DEX Trade Monitoring

JavaScript

// Monitor DEX trading activity
async function monitorDEXTrades(dexAddress, fromBlock) {
  const swapTopic = id('Swap(address,address,int256,int256,uint160,uint128,int24)');
  
  const logs = await new EventMonitor(provider).getPaginatedLogs({
    fromBlock: toQuantity(fromBlock),
    toBlock: 'latest',
    address: dexAddress,
    topics: [swapTopic]
  });
  
  const trades = logs.map(log => {
    // Decode Uniswap V3 swap event
    const iface = new Interface([
      'event Swap(address indexed sender, address indexed recipient, int256 amount0, int256 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick)'
    ]);
    
    const decoded = iface.parseLog({
      topics: log.topics,
      data: log.data
    });
    
    return {
      sender: decoded.args.sender,
      recipient: decoded.args.recipient,
      amount0: decoded.args.amount0.toString(),
      amount1: decoded.args.amount1.toString(),
      price: Number(decoded.args.sqrtPriceX96) ** 2 / (2 ** 192),
      blockNumber: log.blockNumber,
      transactionHash: log.transactionHash
    };
  });
  
  return trades;
}

3. Contract Event Indexer

JavaScript

// Build an event index for a contract
class EventIndexer {
  constructor(provider, contractAddress, abi) {
    this.provider = provider;
    this.contractAddress = contractAddress;
    this.iface = new Interface(abi);
    this.eventIndex = new Map();
  }
  
  async indexEvents(fromBlock, toBlock) {
    // Get all events for the contract
    const logs = await new EventMonitor(this.provider).getPaginatedLogs({
      fromBlock: toQuantity(fromBlock),
      toBlock: toBlock === 'latest' ? 'latest' : toQuantity(toBlock),
      address: this.contractAddress
    });
    
    for (const log of logs) {
      try {
        const parsed = this.iface.parseLog({
          topics: log.topics,
          data: log.data
        });
        
        if (!this.eventIndex.has(parsed.name)) {
          this.eventIndex.set(parsed.name, []);
        }
        
        this.eventIndex.get(parsed.name).push({
          args: Object.fromEntries(
            Object.entries(parsed.args).filter(([key]) => isNaN(key))
          ),
          blockNumber: log.blockNumber,
          transactionHash: log.transactionHash,
          logIndex: log.logIndex
        });
      } catch {
        // Unknown event
      }
    }
    
    return this.getStatistics();
  }
  
  getStatistics() {
    const stats = {};
    
    for (const [eventName, events] of this.eventIndex) {
      stats[eventName] = {
        count: events.length,
        firstBlock: Math.min(...events.map(e => e.blockNumber)),
        lastBlock: Math.max(...events.map(e => e.blockNumber))
      };
    }
    
    return stats;
  }
}

Returns an array of all logs matching a given filter object. Essential for querying historical events and monitoring smart contract activity.

Block Range Limits

Plan	Maximum blocks per request
Free	Not available
Developer	500
Growth	10,000
Scale and above	10,000

When to Use This Method

eth_getLogs is crucial for:

Event Monitoring - Track smart contract events and state changes
Historical Queries - Search past events within a block range
DeFi Analytics - Monitor trades, liquidity events, and protocol activity
Indexing - Build databases of on-chain events

{
  "jsonrpc": "2.0",
  "method": "eth_getLogs",
  "params": [{
    "fromBlock": "0x1",
    "toBlock": "0xc8",
    "address": [
      "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
      "0x4200000000000000000000000000000000000006"
    ],
    "topics": [
      "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
    ]
  }],
  "id": 1
}

Topic Filtering with OR Logic

JSON

{
  "jsonrpc": "2.0",
  "method": "eth_getLogs",
  "params": [{
    "fromBlock": "0x1",
    "toBlock": "0xc8",
    "topics": [
      [
        "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
        "0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925"
      ]
    ]
  }],
  "id": 1
}

Notes

Centrifuge supports historical log queries back to genesis block
Query limits: Maximum 10,000 results per request
Block range limits: Developer 500; Growth, Scale, and Enterprise 10,000 blocks per request
Topic arrays: Support up to 4 topics with OR logic within each position
Performance tip: Use specific address filters to improve query speed
Event signatures: First topic is always the keccak256 hash of the event signature

Common Use Cases

1. Token Balance History

JavaScript

// Track historical token balance changes
async function getBalanceHistory(tokenAddress, userAddress, fromBlock) {
  const monitor = new EventMonitor(provider);
  
  // Get all transfers involving the user
  const logs = await monitor.getFilteredTransfers(
    tokenAddress,
    userAddress,
    'both',
    fromBlock,
    'latest'
  );
  
  // Calculate balance changes
  const balanceChanges = [];
  let currentBalance = 0n;
  
  for (const log of logs) {
    const iface = new Interface([
      'event Transfer(address indexed from, address indexed to, uint256 value)'
    ]);
    
    const decoded = iface.parseLog({
      topics: log.topics,
      data: log.data
    });
    
    const change = decoded.args.from.toLowerCase() === userAddress.toLowerCase() ?
      -decoded.args.value : decoded.args.value;
    
    currentBalance += change;
    
    balanceChanges.push({
      blockNumber: log.blockNumber,
      transactionHash: log.transactionHash,
      change: change.toString(),
      balance: currentBalance.toString(),
      type: change < 0 ? 'outgoing' : 'incoming'
    });
  }
  
  return balanceChanges;
}

2. DEX Trade Monitoring

JavaScript

// Monitor DEX trading activity
async function monitorDEXTrades(dexAddress, fromBlock) {
  const swapTopic = id('Swap(address,address,int256,int256,uint160,uint128,int24)');
  
  const logs = await new EventMonitor(provider).getPaginatedLogs({
    fromBlock: toQuantity(fromBlock),
    toBlock: 'latest',
    address: dexAddress,
    topics: [swapTopic]
  });
  
  const trades = logs.map(log => {
    // Decode Uniswap V3 swap event
    const iface = new Interface([
      'event Swap(address indexed sender, address indexed recipient, int256 amount0, int256 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick)'
    ]);
    
    const decoded = iface.parseLog({
      topics: log.topics,
      data: log.data
    });
    
    return {
      sender: decoded.args.sender,
      recipient: decoded.args.recipient,
      amount0: decoded.args.amount0.toString(),
      amount1: decoded.args.amount1.toString(),
      price: Number(decoded.args.sqrtPriceX96) ** 2 / (2 ** 192),
      blockNumber: log.blockNumber,
      transactionHash: log.transactionHash
    };
  });
  
  return trades;
}

3. Contract Event Indexer

JavaScript

// Build an event index for a contract
class EventIndexer {
  constructor(provider, contractAddress, abi) {
    this.provider = provider;
    this.contractAddress = contractAddress;
    this.iface = new Interface(abi);
    this.eventIndex = new Map();
  }
  
  async indexEvents(fromBlock, toBlock) {
    // Get all events for the contract
    const logs = await new EventMonitor(this.provider).getPaginatedLogs({
      fromBlock: toQuantity(fromBlock),
      toBlock: toBlock === 'latest' ? 'latest' : toQuantity(toBlock),
      address: this.contractAddress
    });
    
    for (const log of logs) {
      try {
        const parsed = this.iface.parseLog({
          topics: log.topics,
          data: log.data
        });
        
        if (!this.eventIndex.has(parsed.name)) {
          this.eventIndex.set(parsed.name, []);
        }
        
        this.eventIndex.get(parsed.name).push({
          args: Object.fromEntries(
            Object.entries(parsed.args).filter(([key]) => isNaN(key))
          ),
          blockNumber: log.blockNumber,
          transactionHash: log.transactionHash,
          logIndex: log.logIndex
        });
      } catch {
        // Unknown event
      }
    }
    
    return this.getStatistics();
  }
  
  getStatistics() {
    const stats = {};
    
    for (const [eventName, events] of this.eventIndex) {
      stats[eventName] = {
        count: events.length,
        firstBlock: Math.min(...events.map(e => e.blockNumber)),
        lastBlock: Math.max(...events.map(e => e.blockNumber))
      };
    }
    
    return stats;
  }
}

eth_getLogs - Query Event Logs

Block Range Limits

When to Use This Method

Implementation Examples

Advanced Usage

Multiple Address Filtering

Topic Filtering with OR Logic

Notes

Common Use Cases

1. Token Balance History

2. DEX Trade Monitoring

3. Contract Event Indexer

On this page

eth_getLogs - Query Event Logs

Block Range Limits

When to Use This Method

Implementation Examples

Advanced Usage

Multiple Address Filtering

Topic Filtering with OR Logic

Notes

Common Use Cases

1. Token Balance History

2. DEX Trade Monitoring

3. Contract Event Indexer

On this page