Block Explorer

DISCLAIMER

This article is a direct copy of the original https://en.bitcoin.it/wiki/Block_chain_browser and has not been checked for correctness or edited. 24 September 2019 Expected review by: 20 October 2019

Review BJL 20190926

Made some minor changes

A Block Explorer is an application that allows users to view and query data stored on the BitcoinSV ledger and network. Typically accessed through a web browser, Block Explorers allow users to view details of Bitcoin blocks, [[Bitcoin Transactions|transactions and addresses. Their primary function is to allow users to track network activity in real-time.

Structure

The structure of a typical block explorer is to have a mining client with a front end that pulls data from its own copy of the blockchain and presents it to users through a web interface.

In future it is expected that block explorers will develop their own tooling and client that can detect additional information that is not typically monitored by a mining client such as the emergence of a block race, transactions which the node is not set up to validate and more.

Real time information on both blocks and transactions is typically provided.

Block information

The explorer provides data on all blocks that have been added to the ledger, and are usually updated within seconds of a valid block being discovered. This data shows:

• Block height: Number of blocks since the Bitcoin Genesis block was mined
• Age: Elapsed time between now and the timestamp that indicates when the block was discovered
• Transaction Count: number of transactions included in the block
• Fees: Fees included in the transactions
• Reward: Total miner reward including transaction fees and block subsidy
• Mined by: Identity of the miner or mining pool who's node mined this block
• Size: Size of the block as obtained by adding the sizes of each transactions included in the block

Real time Transaction information

In addition the block explorer provides a full set of information regarding transactions that have either been mined into a block, or accepted into the Block Explorer's node client's mempool.

• Block: The hash of the block in which the transaction was mined (if the transaction has not yet been mined, the confirmation field is typically not shown)
• Status: If a transaction isn't mined, this field may show the transaction as Unconfirmed
• Timestamp:The timestamp in the block header in which this transaction was mined (if the transaction has not yet been mined, the timestamp field is typically not shown)
• Version:The version of the protocol against which this transaction is to be validated
  • Size:The size of the serialised transaction in bytes
• Confirmations: The number of blocks mined on top of the block containing the transaction (if the transaction has not yet been mined, the confirmation field is typically not shown)
• Fee Paid: The total transaction fee paid by the spending party
• Fee Rate: The transaction fees paid by the spending party as a ratio of Satoshis/Byte which is the total fee paid divided by the size of the transaction

The browser

In the same way as with an Internet browser, the user needs to enter a request to begin his search. It can be a transaction hash or TXID <ref>beginning-blockchain-guide-building-solutions p.278 - Bikramaditya Singhal - ISBN 978-1484234433</ref>(sequence of 64 characters hexadecimal (0 to 9 and a to f) numbers used to uniquely identify a particular transaction) or a block height for example. Automatically, a page containing all the details about the transaction is loaded according to the request. Advanced information contains all the movements in this transaction and is only available at the user's request. Most of the time, a Bitcoin transaction has several input and output addresses insofar as it allows a sender to save time and money by sending to several addresses at once. All the following data will be displayed:

TXID: as mentioned above

Input: transaction inputs are pointers to UTXO <ref>Blockchain Enabled Application p.18 - David Metcalf - ISBN 978-1484230800</ref>. They point to a specific UTXO by reference to the transaction hash and sequence number where the UTXO is recorded in the blockchain.

Output: contains instructions for sending bitcoins <ref>Blockchain Enabled Application p.18 - David Metcalf - ISBN 978-1484230800</ref>.

Value: the number of Satoshi (1 BTC = 100,000,000 Satoshi) that this output will be worth when claimed.

ScriptPubKey: the second half of a script. There can be more than one output. Because each output from one transaction can only ever be referenced once by an input of a subsequent transaction, the entire combined input value needs to be sent in an output if the user doesn't want to lose it. <ref>beginning-blockchain-guide-building-solutions p.201-202 - Bikramaditya Singhal - ISBN 978-1484234433</ref> If the input is worth 50 BTC but a consumer only want to send 25 BTC, Bitcoin will create two outputs worth 25 BTC. This section is divided into two parts. The first, the top line, showing the total amount that the recipient has to receive in BTC, known as the destination. And the other part, below, showing the amount of bitcoins back to the user that remains in the wallet and which can be used as a new input in a subsequent transaction. Any input bitcoins not redeemed in an output is considered a transaction fee.

Transaction Fees: most transactions include transaction fees, which compensate the Bitcoin miners for securing the network. Transaction fees serve as an incentive to include (mine) a transaction into the next block and also as a disincentive against “spam” transactions or any kind of abuse of the system, by imposing a small cost on every transaction. Transaction fees are collected by the miner who mines the block that records the transaction on the blockchain. <ref>Mastering Bitcoin p.127 - Andreas M. Antonopoulos - ISBN 978-1491954386</ref>

Coinbase Data: This field must be between 2 and 100 bytes. Except for the first few bytes the rest of the coinbase data can be used by miners in any way they want; it is arbitrary data. In the genesis block, for example, Satoshi Nakamoto added the text “The Times 03/Jan/ 2009 Chancellor on brink of second bailout for banks” in the coinbase data, using it as a proof of the date and to convey a message. Currently, miners use the coinbase data to include extra nonce values and strings identifying the mining pool. <ref>Mastering Bitcoin p.225 - Andreas M. Antonopoulos - ISBN 978-1491954386</ref>

List of blockchain explorers

• https://whatsonchain.com