Spark Address

A minimal, no-std-compatible Rust library for encoding and decoding Spark Bech32m addresses.

• 100 % safe Rust
• Works in no_std + alloc environments
• Optional secp256k1 public-key validation

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Quick start

Add the crate to your Cargo.toml:

spark-address = "0.1"

Enable optional features if you need them:

spark-address = { version = "0.1", default-features = false, features = ["validate-secp256k1"] }

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Example

use spark_address::{
    encode_spark_address, decode_spark_address, SparkAddressData, Network,
};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Compressed 33-byte secp256k1 public key (hex encoded)
    let pubkey = "0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798";

    // Build the data structure we want to encode
    let data = SparkAddressData {
        identity_public_key: pubkey.into(),
        network: Network::Mainnet,
    };

    // Encode → `sp1…`
    let addr = encode_spark_address(&data)?;
    println!("Spark address: {addr}");

    // Decode back
    let decoded = decode_spark_address(&addr)?;
    assert_eq!(decoded, data);
    Ok(())
}

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Features

Feature	Default	Description
std	✓	Use the Rust standard library. Disable it for #![no_std] targets.
validate-secp256k1		Verify that the supplied public key is a valid compressed secp256k1 key (uses the secp256k1 crate).

The crate has no transitive dependencies beyond bech32 and hex (plus secp256k1 when validation is enabled).

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Address format

A Spark address is a standard Bech32m string consisting of:

1. A human-readable part (HRP) identifying the network: sp, spt, sps, sprt, or spl.
2. A tiny protobuf-like payload containing a single field (tag 0x0a) that wraps a 33-byte compressed secp256k1 public key.

For full details see the implementation in src/lib.rs.

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License

Licensed under either of

• Apache License, Version 2.0, or
• MIT license

at your option.