Arbitrum MCP Server

Instructions

Implementation Reference

• src/clients/nitro-node-client.ts:70-85 (handler)

  Core handler function that executes the RPC call to 'arb_getHealth' to retrieve node health status and handles errors gracefully.

  async getHealth(): Promise<NodeHealth> {
    try {
      const response = await this.makeRpcCall("arb_getHealth", []);
      return {
        status: response.status || "unknown",
        lastUpdated: new Date().toISOString(),
      };
    } catch (error) {
      return {
        status: "unavailable",
        lastUpdated: new Date().toISOString(),
        error:
          "Health check not supported on this RPC endpoint. This method typically requires access to a node's admin API.",
      };
    }
  }

• src/index.ts:154-168 (handler)

  MCP server request handler for the 'node_health' tool call, which resolves the RPC URL, instantiates NitroNodeClient, calls getHealth(), and returns the JSON-formatted result.

  case "node_health": {
    const rpcUrl = await this.resolveRpcUrl(
      (args.rpcUrl as string) || (args.chainName as string)
    );
    const nodeClient = new NitroNodeClient(rpcUrl);
    const health = await nodeClient.getHealth();
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(health, null, 2),
        },
      ],
    };
  }

• src/index.ts:854-873 (schema)

  Tool schema definition and registration in the list of available tools, including input schema for rpcUrl or chainName.

  {
    name: "node_health",
    description:
      "Check Arbitrum node health status (requires admin API access - may 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)",
        },
        chainName: {
          type: "string",
          description:
            "Chain name (e.g., 'Xai', 'Arbitrum One') - will auto-resolve to RPC URL",
        },
      },
      required: [],
    },

• src/clients/nitro-node-client.ts:3-7 (schema)

  TypeScript interface defining the structure of the NodeHealth response object used by the getHealth() method.

  export interface NodeHealth {
    status: string;
    lastUpdated: string;
    error?: string;
  }