lookupAddress
Resolve Ethereum addresses to human-readable ENS names using the MCP Ethers Wallet server. Specify network or RPC URL for cross-chain lookups.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| address | Yes | The Ethereum address to resolve | |
| 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. | |
| chainId | No | Optional. The chain ID to use. If provided with a named network and they don't match, the RPC's chain ID will be used. |
Implementation Reference
- src/tools/core.ts:786-837 (registration)Registration of the 'lookupAddress' MCP tool using server.tool(), including schema and handler function.server.tool( "lookupAddress", { address: z.string().describe( "The Ethereum address to resolve" ), provider: z.string().optional().describe(PROVIDER_DESCRIPTION), chainId: z.number().optional().describe( "Optional. The chain ID to use. If provided with a named network and they don't match, the RPC's chain ID will be used." ) }, async ({ address, provider, chainId }) => { try { const ethProvider = await ethersService.getProvider(provider, chainId); // Look up the ENS name for an address const name = await ethProvider.lookupAddress(address); if (!name) { return { content: [{ type: "text", text: JSON.stringify({ address, resolved: false, message: "No ENS name found for this address" }, null, 2) }] }; } return { content: [{ type: "text", text: JSON.stringify({ address, name, resolved: true }, null, 2) }] }; } catch (error) { return { isError: true, content: [{ type: "text", text: `Error looking up ENS address: ${error instanceof Error ? error.message : String(error)}` }] }; } } );
- src/tools/core.ts:797-836 (handler)Handler function that performs ENS reverse lookup: resolves Ethereum address to ENS name using ethers Provider.lookupAddress method.async ({ address, provider, chainId }) => { try { const ethProvider = await ethersService.getProvider(provider, chainId); // Look up the ENS name for an address const name = await ethProvider.lookupAddress(address); if (!name) { return { content: [{ type: "text", text: JSON.stringify({ address, resolved: false, message: "No ENS name found for this address" }, null, 2) }] }; } return { content: [{ type: "text", text: JSON.stringify({ address, name, resolved: true }, null, 2) }] }; } catch (error) { return { isError: true, content: [{ type: "text", text: `Error looking up ENS address: ${error instanceof Error ? error.message : String(error)}` }] }; } }
- src/tools/core.ts:788-796 (schema)Zod input schema for the lookupAddress tool, validating address (required string), optional provider and chainId.{ address: z.string().describe( "The Ethereum address to resolve" ), provider: z.string().optional().describe(PROVIDER_DESCRIPTION), chainId: z.number().optional().describe( "Optional. The chain ID to use. If provided with a named network and they don't match, the RPC's chain ID will be used." ) },