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The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server340 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

418 bytes · SHA-256 772ce4dd4dd67792… · View upstream ↗

1// Copyright (c) 2023-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#ifndef BITCOIN_KERNEL_MESSAGESTARTCHARS_H
6#define BITCOIN_KERNEL_MESSAGESTARTCHARS_H
7
8#include <array>
9#include <cstdint>
10
11using MessageStartChars = std::array<uint8_t, 4>;
12
13#endif // BITCOIN_KERNEL_MESSAGESTARTCHARS_H
14

FILE GUIDE · KEY SECTIONS

Four-byte network message markers

MessageStartChars gives a shared name to a fixed-size array of four unsigned bytes.

Line 11 ↗

Represent a marker without defining its value

The alias guarantees the width and element type. It does not choose mainnet or testnet bytes, parse a message, or authenticate a peer. Network-specific values and checks are supplied by other components. A recognizable message prefix alone cannot establish that the enclosed block is valid.

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Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.