X402.Signer.SolanaKey (X402 v0.6.0)

X402.Signer backed by a raw Ed25519 private key held in memory.

Signs Solana transaction message bytes through OTP's :crypto (EdDSA on the ed25519 curve) — no extra dependencies. new/1 accepts:

a raw 32-byte Ed25519 seed
a 64-byte Solana keypair (seed <> public_key, the solana-keygen format) — the embedded public key is checked against the derived one
the Base64 or Base58 encoding of either

The struct redacts the private key when inspected, but the key still lives in process memory — prefer an external signer implementation (KMS, hardware wallet) for production payers holding significant funds.

Examples

{:ok, signer} = X402.Signer.SolanaKey.new(:crypto.strong_rand_bytes(32))
{:ok, address} = X402.Signer.SolanaKey.address(signer)

Summary

Types

t()

A local Ed25519 signing key with its derived Solana address.

Functions

address(solana_key)

Returns the Base58 Solana address derived from the private key.

new(private_key)

Builds a signer from an Ed25519 seed or Solana keypair.

sign_ed25519(solana_key, message)

Signs message with the local Ed25519 key.

Types

t()

@type t() :: %X402.Signer.SolanaKey{address: String.t(), seed: binary()}

A local Ed25519 signing key with its derived Solana address.

Functions

address(solana_key)

(since 0.6.0)

@spec address(t()) :: {:ok, String.t()}

Returns the Base58 Solana address derived from the private key.

new(private_key)

(since 0.6.0)

@spec new(binary()) :: {:ok, t()} | {:error, :invalid_private_key}

Builds a signer from an Ed25519 seed or Solana keypair.

Returns {:error, :invalid_private_key} for malformed keys and for 64-byte keypairs whose public half does not match the seed.

Examples

iex> {:ok, signer} = X402.Signer.SolanaKey.new(:binary.copy(<<1>>, 32))
iex> signer.address
"AKnL4NNf3DGWZJS6cPknBuEGnVsV4A4m5tgebLHaRSZ9"

iex> X402.Signer.SolanaKey.new("not a key")
{:error, :invalid_private_key}

sign_ed25519(solana_key, message)

(since 0.6.0)

@spec sign_ed25519(t(), binary()) :: {:ok, X402.Signer.ed25519_signature()}

Signs message with the local Ed25519 key.

Ed25519 signing is deterministic (RFC 8032), so the same key and message always produce the same 64-byte signature.