Bitcoin Education
Bitcoin Learning Sandbox
Explore wallets, UTXOs, fees, mempool priority, and block confirmations — all simulated locally. No real coins or nodes required.
Documentation
How the Bitcoin Learning Sandbox works — architecture, flow, and API reference.
Overview
Educational simulator — mock keys, session-based UTXOs, mempool, and blocks. No real Bitcoin node.
1. Wallet → Keys → Addresses
Private key (hex) → WIF → public key → HASH160 → Legacy 1... and SegWit bc1q... addresses. Starter UTXOs are auto-funded for practice.
2. UTXO Model
Balance = sum of unspent outputs. Each UTXO has txid, vout, address, and amount_sats. Spending marks inputs as used.
3. Transaction Builder
fee = fee_rate × vsize · change = inputs − amount − fee. Outputs JSON shows vin and vout including change. Dust (<546 sats) rejected.
4. Mempool & Fees
Higher sat/vB = higher queue position. Top transactions are picked first when mining. Fee slider (1–200 sat/vB) updates confirmation estimates live.
5. Block Mining
Mine Next Block confirms mempool txs, increments height, credits change UTXOs, and logs events in the explorer feed.
6. Security Lessons
- Address reuse — second spend from same address triggers privacy warning
- Key exposure — exposed private key is swept on next block
Flow
Generate Wallet → Build TX → Broadcast → Mempool Queue → Mine Block → Confirmed
Wallet Generator
Private Key (hex)
WIF (compressed)
Public Key (compressed)
Legacy Address
SegWit Address
Derivation Steps
Mock UTXOs
Click Generate Keypair to create a mock wallet with starter UTXOs.
Transaction Builder
Raw Mock Transaction JSON
Fee & Mempool Simulator
Estimated confirmation:
Mempool is empty. Broadcast a transaction to see fee competition.
Blockchain Explorer
Recent Blocks
No blocks mined yet in this session.
Explorer Feed
Security Lessons
Address Reuse
Broadcast two transactions from the same address to trigger a privacy warning.
Private Key Exposure
Paste or expose your mock private key, then mine a block to simulate a sweep attack.