Avalanche

Avalanche

eth_getTransactionByBlockHashAndIndex

The eth_getTransactionByBlockHashAndIndex method retrieves transaction information for a specific transaction position within a block, identified by the block's hash.

Use Cases

• Building block explorers to display transaction details
• Analyzing specific transaction positions within blocks
• Verifying transaction inclusion in specific blocks
• Auditing transaction sequences in historical blocks
• Blockchain forensics and transaction tracing
• Smart contract event and state analysis
• Cross-referencing transactions across indexes
• Validating transaction execution order

Method Details

Returns transaction data at the specified index position from a block with the given hash.

Transaction Types

Ethereum transactions have evolved through several formats:

Response Example

1{
2  "jsonrpc": "2.0",
3  "id": 1,
4  "result": {
5    "blockHash": "0xc0f4906fea23cf6f3cce98cb44e8e1449e455b28d684dfa9ff65426495584de6",
6    "blockNumber": "0x1b4",
7    "from": "0x687422eea2cb73b5d3e242ba5456b782919afc85",
8    "gas": "0x4c4b40",
9    "gasPrice": "0x1",
10    "hash": "0xc55e2b90168af6972193c1f86fa4d7d7b31a29c156665d15b9cd48618b5177ef",
11    "input": "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",
12    "nonce": "0x4",
13    "to": null,
14    "transactionIndex": "0x0",
15    "value": "0x0",
16    "type": "0x0",
17    "v": "0x1b",
18    "r": "0x9db4a2414dcfac7e25b6c0fc771a4fbe5a582f640f6f8ed673970e318494e674",
19    "s": "0x6cf121d02b5fcd61cec1b8a295b9006c7b137c39162386d968e9310cc2c81b83"
20  }
21}

Understanding Transaction Fields

Basic Transaction Information

The transaction object returned by this method contains important fields:

• blockHash/blockNumber: Identifies where this transaction is stored in the blockchain
• transactionIndex: Position of the transaction within the block (0 is first transaction)
• hash: Unique identifier for the transaction
• from: Sender's address (who initiated and signed the transaction)
• to: Recipient address (null indicates contract creation)
• value: Amount of ETH transferred in wei (hexadecimal)
• input: For contract creation/interaction, contains bytecode or encoded function call
• nonce: Sender's transaction count (used to prevent replays)

Gas and Fee Information

Gas and fee fields vary by transaction type:

• gas: Maximum gas the transaction can use
• gasPrice: Price per unit of gas (in legacy and Type-1 transactions)
• maxFeePerGas: Maximum total fee per gas unit (in Type-2 transactions)
• maxPriorityFeePerGas: Maximum priority fee per gas unit (in Type-2 transactions)

Signature Components

The transaction signature consists of three parts:

• v: Recovery ID (helps derive the public key from the signature)
• r and s: The ECDSA signature components

Distinguishing Contract Creation Transactions

You can identify contract creation transactions by checking if the to field is null. For example:

1async function isContractCreation(blockHash, txIndex) {
2  const tx = await ethereum.request({
3    method: 'eth_getTransactionByBlockHashAndIndex',
4    params: [blockHash, txIndex]
5  });
6  
7  return tx.to === null;
8}

For contract creation transactions, the contract address can be derived from:

• Sender address (from)
• Sender's nonce at that time
• Transaction data

Differences From Related Methods

This method differs from other transaction lookup methods:

The block hash-based method provides absolute certainty that you're querying the right block, even in reorg situations, while the block number method is more convenient for sequential access patterns.

See also

• eth_getTransactionByHash - Get transaction information by transaction hash
• eth_getTransactionByBlockNumberAndIndex - Get transaction by block number and index position
• eth_getBlockByHash - Get complete block information including all transactions
• eth_getTransactionReceipt - Retrieve transaction receipt with execution results

1curl https://avalanche.therpc.io \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionByBlockHashAndIndex","params":["0xc0f4906fea23cf6f3cce98cb44e8e1449e455b28d684dfa9ff65426495584de6","0x0"]}'