ethSign
Sign data on Ethereum networks using a standardized interface. Convert data to hex, specify a network or RPC URL, and generate secure signatures for blockchain operations.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | The data to sign. Will be converted to hex if not already in hex format. | |
| provider | No | Optional. Either a network name or custom RPC URL. Use getAllNetworks to see available networks and their details, or getNetwork to get info about a specific network. You can use any network name returned by these tools as a provider value. |
Implementation Reference
- src/tools/core.ts:676-728 (handler)Full implementation of the 'ethSign' MCP tool: registers the tool, defines input schema (data: string/hex, optional provider), and provides the handler logic that signs data with a loaded Ethereum wallet using ethers.Wallet.signMessage(ethers.getBytes(hexData)) as a proxy for the legacy eth_sign RPC method. Handles non-hex data by converting to bytes via Buffer."ethSign", { data: z.string().describe( "The data to sign. Will be converted to hex if not already in hex format." ), provider: z.string().optional().describe(PROVIDER_DESCRIPTION) }, async ({ data, provider }) => { try { // First check if a wallet exists const wallet = await ethersService.getWallet(provider); if (!wallet) { return { isError: true, content: [{ type: "text", text: "No wallet available to sign data. Please create or load a wallet first." }] }; } // Ensure data is in hex format let hexData = data; if (!data.startsWith("0x")) { // Convert string to hex hexData = "0x" + Buffer.from(data).toString("hex"); } // Sign the data using eth_sign // Note: ethers.js v6 doesn't have a direct eth_sign method, so we're using signMessage as an alternative // In a real implementation, you'd use a provider's send method with eth_sign const signature = await wallet.signMessage(ethers.getBytes(hexData)); return { content: [{ type: "text", text: JSON.stringify({ data: hexData, signature, signer: wallet.address }, null, 2) }] }; } catch (error) { return { isError: true, content: [{ type: "text", text: `Error using eth_sign: ${error instanceof Error ? error.message : String(error)}` }] }; } }