BTC2 Block Explorer

A block explorer is a tool that allows you to search and navigate the blockchain. You can use it to:

• Look up transactions by their ID
• Check the balance of any address
• View the contents of any block
• Track the history of coins as they move between addresses

Think of it like a search engine for the blockchain - it makes the public ledger readable and searchable.

Unspent means the coins are still at that address and can be used. This represents actual available balance.

Spent means the coins were sent somewhere else in a later transaction. They're no longer available at that address.

An address's balance is calculated by adding up all of its Unspent outputs. Spent outputs are historical records showing where coins used to be.

UTXO stands for Unspent Transaction Output. It's the fundamental way BTC2 (and Bitcoin) tracks ownership of coins.

Instead of maintaining account balances like a bank, the blockchain tracks individual "chunks" of coins. Each UTXO is like a specific coin or bill that you own.

A block is a collection of transactions that have been verified and added to the blockchain. Each block contains:

• Block Height - Its position in the chain (Block 1, Block 2, etc.)
• Hash - A unique identifier (like a fingerprint)
• Transactions - All the transfers included in this block
• Timestamp - When the block was created
• Merkle Root - A cryptographic summary of all transactions

Blocks are linked together in a chain, with each block referencing the previous one. This creates an immutable history of all transactions.

A Transaction ID (TXID) is a unique 64-character identifier for a specific transaction. It's generated by hashing the transaction data.

You can use a TXID to:

• Look up transaction details
• Verify that a payment was made
• Track where coins came from or went to

Example TXID: a1b2c3d4e5f6...7890abcdef

There are two ways to check a balance:

1. Search bar: Enter the address in the search bar on any page and press Enter
2. Direct URL: Go to /address.html?addr=YOUR_ADDRESS

The address page will show the current balance, total received, total sent, and transaction history.

Use the Search page to filter transactions:

1. Go to the Search page
2. Select an operator (equals, greater than, less than, etc.)
3. Enter the amount in BTC2
4. Optionally filter by a specific address
5. Click Search

The main search bar accepts:

• Block height - A number like 12345
• Block hash - A 64-character hex string
• Transaction ID - A 64-character hex string
• Address - A BTC2 address (typically 26-35 characters)

The explorer will automatically detect what you're searching for and show the appropriate page.

There are a few reasons a transaction might not show up:

• Not synced yet: The explorer syncs blocks from the BTC2 node. If the transaction is in a recent block, the explorer may not have indexed it yet.
• Still unconfirmed: This explorer only shows confirmed transactions (those included in blocks). Unconfirmed/mempool transactions are not displayed.
• Typo: Double-check that the transaction ID or address is correct.

Balance is calculated using the UTXO model:

Balance = Sum of all Unspent Transaction Outputs for that address

The explorer scans all transaction outputs sent to an address, subtracts any that have been spent, and the remainder is the current balance.

The Merkle Root is a single hash that summarizes all transactions in a block. It's created by:

1. Hashing each transaction
2. Pairing up the hashes and hashing them together
3. Repeating until only one hash remains

This allows anyone to verify that a specific transaction is included in a block without downloading all transactions - they only need the Merkle Root and a small "proof path."