Arbitrum MCP Server

Instructions

Implementation Reference

• src/clients/nitro-node-client.ts:136-152 (handler)

  Core implementation of getPeers() method in NitroNodeClient that performs the 'admin_peers' RPC call and maps the response to PeerInfo objects.
  async getPeers(): Promise<PeerInfo[] | { error: string }> { try { const peers = await this.makeRpcCall("admin_peers", []); return peers.map((peer: any) => ({ id: peer.id, name: peer.name, caps: peer.caps, network: peer.network, protocols: peer.protocols, })); } catch (error) { return { error: "Peer information not supported on this RPC endpoint. This method typically requires access to a node's admin API.", }; } }
• src/index.ts:186-200 (handler)

  MCP server handler for the 'node_peers' tool: resolves RPC URL using chainLookupService, instantiates NitroNodeClient, calls getPeers(), and formats response as JSON text.
  case "node_peers": { const rpcUrl = await this.resolveRpcUrl( (args.rpcUrl as string) || (args.chainName as string) ); const nodeClient = new NitroNodeClient(rpcUrl); const peers = await nodeClient.getPeers(); return { content: [ { type: "text", text: JSON.stringify(peers, null, 2), }, ], }; }
• src/index.ts:891-906 (registration)

  Tool registration in getAvailableTools(): defines name, description, and inputSchema for 'node_peers' tool.
  { name: "node_peers", description: "Get connected peers information (requires admin API access - will not work with public RPCs)", inputSchema: { type: "object" as const, properties: { rpcUrl: { type: "string", description: "The RPC URL of the Arbitrum node (optional if default is set)", }, }, required: [], }, },
• src/clients/nitro-node-client.ts:17-26 (schema)

  TypeScript interface defining the structure of PeerInfo returned by getPeers() method.
  export interface PeerInfo { id: string; name: string; caps: string[]; network: { localAddress: string; remoteAddress: string; }; protocols: Record<string, any>; }