# BTC21 — Public Bitcoin Infrastructure > BTC21 is an independent public Bitcoin infrastructure project operated by Bitseeker LLC, a Wyoming limited liability company. Its core public infrastructure is currently provided free of charge as a community contribution. BTC21 remains the public-facing project identity; Bitseeker LLC is the responsible operator. ## Core Services & Endpoints - Clearnet Node: btc21.cc:8333 - Tor v3 Onion Node: 2hi75…o7fhfdxtad.onion:8333 - Block Explorer: https://explorer.btc21.cc - Electrum Service: https://electrum.btc21.cc - Tor Privacy Guide: https://btc21.cc/tor/ - Electrum Tor Setup: https://electrum.btc21.cc/tor/ - Bitcoin Wallet Basics: https://btc21.cc/wallets/ - Raw Transaction Broadcaster: https://btc21.cc/#broadcast ## Technical Specifications - Implementation: Bitcoin Core 31.0 - Chain: Mainnet - Node Type: Full archival (prune=0, txindex=1) - P2P Protocol: BIP324 (v2 encrypted transport) enabled - Filter Support: BIP157 / BIP158 compact filters enabled - Mempool: 2,000 MB capacity, Full-RBF enabled - Max Inbound/Outbound Peers: 1,000 ## Privacy & Security Policy - BTC21 collects zero telemetry, uses no ad pixels, sets no tracking cookies, and runs no user analytics. - Non-Custodial: BTC21 never holds private keys, provides no wallet generation, and manages no user funds. - Abuse Prevention: Raw transaction relay endpoints are rate-limited via client-side Proof-of-Work anti-spam filters. - Current access: No account, subscription, or payment is currently required to use the public services described here. Features or services may change in the future.