read-contract
Call read-only functions on smart contracts to retrieve blockchain data without executing transactions, using ABI, contract address, and function parameters.
Instructions
Call a read-only function on a contract, and returning the response
Tool call template
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"abi": "<abi>",
"address": "<address>",
"functionName": "<functionName>",
"args": "<args>"
},
"name": "read-contract"
}
}Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| abi | Yes | ||
| address | Yes | ||
| functionName | Yes | ||
| args | Yes |
Implementation Reference
- Implements the core logic of the 'read-contract' tool by calling readContract from @wagmi/core, parsing ABI, and formatting the result or error as text content.
execute: async (_args) => { try { const abi = JSON.parse(_args.abi) as Abi const address = _args.abi as Address const functionName = _args.functionName const args = _args.args const result = await readContract(wagmiConfig, { abi, address, functionName, args, }) return { content: [ { type: "text", text: `${result}`, }, ], } } catch (error) { if (error instanceof TransactionExecutionError) { return { content: [ { type: "text", text: error.cause.message, } ] } } return { content: [ { type: "text", text: (error as Error).message, } ] } } }, - Zod schema defining the input parameters for the 'read-contract' tool: abi (string), address (string), functionName (string), args (array of strings).
parameters: z.object({ abi: z.string(), address: z.string(), functionName: z.string(), args: z.string().array() }), - packages/metamask-mcp/src/tools/read-contract.ts:7-59 (registration)Registers the 'read-contract' tool on the FastMCP server, including name, description, schema, and handler.
export function registerReadContractTools(server: FastMCP): void { server.addTool({ name: "read-contract", description: "Call a read-only function on a contract, and returning the response", parameters: z.object({ abi: z.string(), address: z.string(), functionName: z.string(), args: z.string().array() }), execute: async (_args) => { try { const abi = JSON.parse(_args.abi) as Abi const address = _args.abi as Address const functionName = _args.functionName const args = _args.args const result = await readContract(wagmiConfig, { abi, address, functionName, args, }) return { content: [ { type: "text", text: `${result}`, }, ], } } catch (error) { if (error instanceof TransactionExecutionError) { return { content: [ { type: "text", text: error.cause.message, } ] } } return { content: [ { type: "text", text: (error as Error).message, } ] } } }, }); }; - packages/metamask-mcp/src/index.ts:54-54 (registration)Invokes the registration of the 'read-contract' tool during server initialization.
registerReadContractTools(server);