Mcp Signer

This server handles local transaction signing for EVM chains (Ethereum, BSC, Polygon, Arbitrum, Base, Optimism), UTXO chains (Bitcoin, Litecoin, Dogecoin), Tron, and XRP without making any network calls. You pass private keys directly to tools like evm_sign, utxo_sign, tron_sign, and xrp_sign, which return signed transaction hex strings ready for broadcast. Each tool supports either signing from structured fields (to, value, gasLimit) or from pre-built unsigned hex. Runs stdio only with no HTTP transport, so nothing listens on a port. Pair it with the mcp-broadcast server to push signed transactions to the blockchain. Good fit when you need offline signing across multiple chains in Claude workflows.