switch-chain
Change blockchain networks in MetaMask for MCPilot server, enabling AI to interact with different chains while maintaining wallet security.
Instructions
Switch the target chain
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| chainId | Yes | ||
| addEthereumChainParameter | No |
Implementation Reference
- The main handler function that executes the chain switch using the wagmi switchChain function. It takes chainId and optional addEthereumChainParameter, calls switchChain, and returns the result as a text content block.
execute: async (args) => { const chainId = args.chainId as typeof wagmiConfig['chains'][number]['id'] const addEthereumChainParameter = args.addEthereumChainParameter const result = await switchChain(wagmiConfig, { chainId, addEthereumChainParameter, }) return { content: [ { type: "text", text: JSONStringify(result), }, ], } }, - Zod schema defining the input parameters for the switch-chain tool: required chainId (number) and optional addEthereumChainParameter object for adding a new chain.
parameters: z.object({ chainId: z.coerce.number(), addEthereumChainParameter: z.object({ chainName: z.string(), nativeCurrency: z.object({ name: z.string(), symbol: z.string(), decimals: z.coerce.number(), }).optional(), rpcUrls: z.string().array(), blockExplorerUrls: z.string().array().optional(), iconUrls: z.string().array().optional(), }).optional() }), - packages/metamask-mcp/src/tools/switch-chain.ts:7-42 (registration)The registration function that adds the switch-chain tool to the FastMCP server, including name, description, schema, and handler.
export function registerSwitchChainTools(server: FastMCP): void { server.addTool({ name: "switch-chain", description: "Switch the target chain", parameters: z.object({ chainId: z.coerce.number(), addEthereumChainParameter: z.object({ chainName: z.string(), nativeCurrency: z.object({ name: z.string(), symbol: z.string(), decimals: z.coerce.number(), }).optional(), rpcUrls: z.string().array(), blockExplorerUrls: z.string().array().optional(), iconUrls: z.string().array().optional(), }).optional() }), execute: async (args) => { const chainId = args.chainId as typeof wagmiConfig['chains'][number]['id'] const addEthereumChainParameter = args.addEthereumChainParameter const result = await switchChain(wagmiConfig, { chainId, addEthereumChainParameter, }) return { content: [ { type: "text", text: JSONStringify(result), }, ], } }, }); }; - packages/metamask-mcp/src/index.ts:57-57 (registration)Top-level call to register the switch-chain tools during server initialization.
registerSwitchChainTools(server);