noble cryptography

Web3Signer is a remote signing service that keeps keys in a vault or hardware security module. Node and validator operators run it so signing happens outside the client process.

The Fireblocks SDK connects applications to Fireblocks' MPC wallet infrastructure for signing, transfers, and treasury operations. Builders use it to automate transactions and approval policies for wallets managed through Fireblocks.

Turnkey offers an API and SDK for secure key generation and transaction signing backed by trusted execution environments. Builders use it to create and operate wallet infrastructure without holding raw private keys in their own code.

Lit Protocol is a decentralized network for threshold key management with programmable signing through its programmable key pairs. Builders use its SDK when signing or decryption should follow rules enforced by a network rather than a single key holder.

eth-keys is a Python library for secp256k1 keys and signatures, and it sits under eth-account and web3.py. Python builders import it when they need key and signature operations directly.

The Ledger hw-app-eth package is the JavaScript API for signing Ethereum transactions and messages with a Ledger device, and it sits behind the Ledger connectors in wagmi and viem. Wallet and application builders import it to add hardware wallet signing.