@solana/keychain-memory

In-memory Ed25519 keypair signer for Solana transactions.

The private key never leaves the local process — all signing happens via the Web Crypto API. Useful for development, integration tests, and server-side signing where a remote vendor is overkill.

Installation

pnpm add @solana/keychain-memory

Usage

From a Solana CLI keypair file

import { createMemorySignerFromKeypairFile } from '@solana/keychain-memory';

const signer = await createMemorySignerFromKeypairFile('/path/to/id.json');
console.log('Signer address:', signer.address);

From a base58 private key string

import { createMemorySignerFromPrivateKeyString } from '@solana/keychain-memory';

const signer = await createMemorySignerFromPrivateKeyString(process.env.SOLANA_PRIVATE_KEY!);

From a U8Array string (Solana CLI inline format)

import { createMemorySignerFromPrivateKeyString } from '@solana/keychain-memory';

const signer = await createMemorySignerFromPrivateKeyString('[1, 2, 3, ..., 64]');

From raw bytes

Accepts either a 64-byte Solana CLI keypair (seed concatenated with public key — seed↔pubkey match is validated) or a 32-byte Ed25519 seed (public key derived).

import { createMemorySignerFromBytes } from '@solana/keychain-memory';

// 64 bytes: Solana CLI format
const signer = await createMemorySignerFromBytes(solanaCliKeypairBytes);

// 32 bytes: raw Ed25519 seed (e.g. exported from generateKey)
const signerFromSeed = await createMemorySignerFromBytes(seed32);

From an existing CryptoKeyPair

import { generateKeyPair } from '@solana/keys';
import { createMemorySignerFromKeyPair } from '@solana/keychain-memory';

const keyPair = await generateKeyPair();
const signer = await createMemorySignerFromKeyPair(keyPair);

Unified factory

import { createMemorySigner } from '@solana/keychain-memory';

const signer = await createMemorySigner({
    privateKeyString: process.env.SOLANA_PRIVATE_KEY!,
});

Provide exactly one of: keyPair, privateKey, privateKeyString, privateKeyPath.

Sign messages and transactions

import { createSignableMessage } from '@solana/signers';

const message = createSignableMessage('Hello, Solana!');
const [messageSignatures] = await signer.signMessages([message]);

const [transactionSignatures] = await signer.signTransactions([transaction]);

Check availability

const available = await signer.isAvailable(); // always true

API Reference

createMemorySigner(config)

Returns Promise<SolanaSigner>.

Config (MemorySignerConfig):

• keyPair?: CryptoKeyPair — pre-built CryptoKeyPair (e.g. from generateKeyPair)
• privateKey?: Uint8Array — 64-byte Solana keypair (seed‖pubkey, validated) OR 32-byte Ed25519 seed (pubkey derived)
• privateKeyString?: string — base58 OR U8Array string "[1, 2, ..., 64]"
• privateKeyPath?: string — path to a Solana CLI keypair JSON file (Node-only)

Named factories

• createMemorySignerFromKeyPair(keyPair)
• createMemorySignerFromBytes(privateKey)
• createMemorySignerFromPrivateKeyString(privateKeyString) — auto-detects base58 vs U8Array
• createMemorySignerFromKeypairFile(privateKeyPath) — Node-only

Security Notes

• The private key is held in memory as a non-extractable CryptoKey — it cannot be exported back to bytes.
• Do not hardcode private keys in source files. Use environment variables, secret managers, or operator-supplied keypair files.
• For production wallets, prefer a remote signer backend (AWS KMS, GCP KMS, Turnkey, Privy, etc.).