Module neo

Expand description

Neo N3 Utilities Module

Provides Neo N3 blockchain-specific utilities for NEF (Neo Executable Format) generation and method tokens.

§Key Components

The Neo Executable Format (NEF) is the standard container for Neo N3 smart contracts, containing bytecode, metadata, and optional method tokens.

MAX_CALL_FLAGS: Bitmask of valid CallFlags values (CallFlags.All). Used to validate call flags in method tokens.
MAX_METHOD_TOKENS: Maximum number of method tokens allowed in a single NEF file. Method tokens enable optimized cross-contract calls. The NEF3 spec permits up to 512 entries; real-world contracts compiled by Neo.Compiler.CSharp / Neow3j can exceed 128.
MAX_SCRIPT_SIZE: Maximum script size in NEF (512 KB)
MAX_TOKEN_METHOD_LENGTH: Maximum byte length of a method name stored in a NEF method token. Method names exceeding this limit will be truncated.
NEF_HEADER_SIZE: NEF header size in bytes
NEF_MAGIC: NEF file magic bytes (“NEF3”)
NEF_SOURCE_MAX_BYTES: Publicly exposed maximum byte length for the NEF source field.

build_nef: Build a NEF (Neo Executable Format) file from raw NeoVM bytecode.
build_nef_with_tokens: Build a NEF file with method tokens for cross-contract calls.
clamp_nef_source: Clamp a NEF source string to the maximum allowed byte length, preserving UTF-8 boundaries.
clamp_nef_source_with_flag: Clamp a NEF source string and report whether truncation occurred.
compute_contract_hash: Compute the Neo N3 contract hash for a deployment transaction.
format_uint160_hex_be: Format a Neo UInt160 (little-endian bytes) as a 0x-prefixed big-endian hex string.
parse_nef: Parse a Neo N3 NEF3 file produced by build_nef_with_tokens.
parse_uint160_hex_be: Parse a Neo UInt160 from a 0x-prefixed (or raw) big-endian hex string.