Signer

Multi-chain transaction signer built on mature cryptography libraries — zero hand-rolled crypto, and a batteries-included CLI.

signer provides thin wrappers around battle-tested signing libraries (alloy for EVM, bitcoin for BTC, ed25519-dalek for Solana), exposing a unified API while delegating all cryptographic operations to upstream crates. All signers Deref to their underlying types for full API access, and private keys are zeroed on drop. Optional kobe integration enables seamless HD wallet bridging.

Crates

Crate		Description
signer		Umbrella crate — re-exports all chain signers
signer-btc		Bitcoin — ECDSA, Schnorr, PSBT, BIP-137 message signing
signer-evm		Ethereum / EVM — EIP-191, EIP-712, transaction signing
signer-svm		Solana / SVM — Ed25519 signing
signer-cli		CLI tool — sign, verify, and inspect keys across all supported chains

Quick Start

Install the CLI

Shell (macOS / Linux):

curl -fsSL https://sh.qntx.fun/signer | sh

PowerShell (Windows):

irm https://sh.qntx.fun/signer/ps | iex

Or via Cargo:

cargo install signer-cli

Sign an Ethereum Message (Library)

use signer_evm::{Signer, SignerSync};

let signer = Signer::random();
let signature = signer.sign_message_sync(b"hello")?;

println!("Address:   {}", signer.address());
println!("Signature: {signature}");

Sign a Bitcoin Message (Library)

use signer_btc::{Signer, Network};

let signer = Signer::random(Network::Bitcoin);
let signature = signer.sign_message("Hello, Bitcoin!")?;
let address = signer.p2wpkh_address(Network::Bitcoin);
let valid = Signer::verify_message("Hello, Bitcoin!", &signature, &address, Network::Bitcoin)?;

println!("Address: {address}");
println!("Valid:   {valid}");

Sign with Solana (Library)

use signer_svm::Signer;
use ed25519_dalek::Signer as _;

let signer = Signer::random();
let sig = signer.sign(b"hello solana");
signer.verify(b"hello solana", &sig)?;

println!("Address: {}", signer.address());

Via Umbrella Crate

use signer::{evm, btc, svm};

let eth_signer = evm::Signer::random();
let btc_signer = btc::Signer::random(btc::Network::Bitcoin);
let sol_signer = svm::Signer::random();

Kobe HD Wallet Integration

Enable the kobe feature to construct signers from kobe derived keys:

use kobe::Wallet;
use kobe_evm::Deriver;
use signer_evm::Signer;

let wallet = Wallet::from_mnemonic("abandon abandon ... about", None)?;
let deriver = Deriver::new(&wallet);
let derived = deriver.derive(0)?;

let signer = Signer::from_derived(&derived)?;
println!("Address: {}", signer.address());

CLI Usage

The CLI uses --json for machine-readable output — ideal for agent and script consumption.

signer [--json] <chain> <subcommand> [options]

Chain subcommands and aliases

Chain	Primary	Aliases
Bitcoin	btc	bitcoin
Ethereum	evm	eth, ethereum
Solana	svm	sol, solana

Bitcoin

# BIP-137 message signing (default: Native SegWit)
signer btc sign-message --key "L1a..." --message "Hello, Bitcoin!"

# Sign with specific address type
signer btc sign-message --key "L1a..." --message "test" --address-type legacy

# Verify a signed message
signer btc verify-message --signature "H..." --message "Hello" --address "bc1q..."

# Raw ECDSA / Schnorr hash signing
signer btc sign-ecdsa   --key "L1a..." --hash "abcdef..."
signer btc sign-schnorr --key "L1a..." --hash "abcdef..."

# Sign a PSBT (base64 in → base64 out)
signer btc sign-psbt --key "L1a..." --psbt "cHNidP8B..."

# Show all address types for a key
signer btc address --key "L1a..."

Ethereum

# EIP-191 personal_sign
signer evm sign-message --key "0xabc..." --message "Hello, Ethereum!"

# Raw hash signing
signer evm sign-hash --key "0xabc..." --hash "0xdef..."

# Sign a raw unsigned transaction (hex-encoded EIP-2718 bytes)
signer evm sign-transaction --key "0xabc..." --tx "0x02f8..."

# Verify a signed message
signer evm verify-message --signature "0x..." --message "Hello" --address "0x..."

# Show address and public key
signer evm address --key "0xabc..."

Solana

# Ed25519 signing
signer svm sign --key "deadbeef..." --message "Hello, Solana!"

# Sign hex-encoded bytes (e.g., serialized transaction)
signer svm sign --key "deadbeef..." --message "0a0b0c..." --hex

# Verify a signature
signer svm verify --signature "abcdef..." --message "Hello" --pubkey "Base58Address..."

# Show address and public key
signer svm address --key "deadbeef..."

JSON output

Pass --json before the chain subcommand. All output (including errors) becomes a single JSON object on stdout with no ANSI colors.

signer --json btc sign-message --key "L1a..." --message "test"

{
  "chain": "bitcoin",
  "operation": "BIP-137 message",
  "address": "bc1q...",
  "signature": "H...",
  "message": "test"
}

Errors in JSON mode return exit code 1 with {"error": "..."}.

Design

• Zero hand-rolled crypto — All signing delegated to audited upstream libraries
• Thin wrappers — Deref to underlying types (PrivateKey, PrivateKeySigner, SigningKey) for full API access
• Memory safety — Private keys zeroed on drop (ZeroizeOnDrop / non_secure_erase)
• Multi-chain — EVM, Bitcoin, Solana from one workspace
• Kobe integration — Optional HD wallet bridging via feature flag
• CSPRNG — Random generation via OS-provided entropy (getrandom)
• Linting — pedantic + nursery + correctness (deny) — strict Clippy across workspace
• Edition — Rust 2024

Signing Methods

EVM (signer-evm)

Method	Standard
sign_hash_sync / sign_hash	Raw 32-byte hash
sign_message_sync / sign_message	EIP-191 personal_sign
sign_typed_data_sync / sign_typed_data	EIP-712 (via alloy)
sign_transaction_sync / sign_transaction	All EVM transaction types

Bitcoin (signer-btc)

Method	Standard
sign_ecdsa	secp256k1 ECDSA
sign_schnorr	BIP-340 Schnorr (Taproot)
sign_message / sign_message_with_type	BIP-137 (P2PKH, P2SH-P2WPKH, P2WPKH)
verify_message	BIP-137 verification
sign_psbt	PSBT (with Bip32Derivation support)
p2wpkh_address / p2tr_address / ...	All address types (P2WPKH, P2TR, P2SH-P2WPKH, P2PKH)

Solana (signer-svm)

Method	Standard
sign (via Deref)	Ed25519 signature
verify	Ed25519 verification
sign_transaction_message	Solana transaction signing
keypair_base58	Phantom / Backpack / Solflare format

Feature Flags

Crate	Feature	Description
signer	btc	Enable Bitcoin signer (default)
signer	evm	Enable EVM signer (default)
signer	svm	Enable Solana signer (default)
signer	kobe	Enable kobe HD wallet bridging for all chains
signer-*	kobe	Enable kobe bridging for a specific chain

Security

This library has not been independently audited. Use at your own risk.

• All cryptographic operations are delegated to upstream libraries
• Private keys are zeroed from memory on drop (EVM/SVM via ZeroizeOnDrop, BTC via non_secure_erase)
• Review the security advisories of upstream dependencies

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT License (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project shall be dual-licensed as above, without any additional terms or conditions.

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