Arbitrum MCP Server

Instructions

Implementation Reference

• src/clients/nitro-node-client.ts:156-170 (handler)

  Core handler function implementing the arb_checkPublisherHealth RPC call to check transaction publisher/sequencer health status. Returns healthy status or error if unsupported.
  async checkPublisherHealth(): Promise<PublisherHealth> { try { await this.makeRpcCall("arb_checkPublisherHealth", []); return { healthy: true, }; } catch (error) { return { healthy: false, error: `Publisher health check failed or not supported on this RPC endpoint: ${ (error as Error).message }`, }; } }
• src/index.ts:412-426 (handler)

  MCP CallTool handler case that resolves the RPC URL using chain name or direct URL, creates NitroNodeClient instance, calls checkPublisherHealth(), and formats response as MCP content.
  case "arb_check_publisher_health": { const rpcUrl = await this.resolveRpcUrl( (args.rpcUrl as string) || (args.chainName as string) ); const nodeClient = new NitroNodeClient(rpcUrl); const health = await nodeClient.checkPublisherHealth(); return { content: [ { type: "text", text: JSON.stringify(health, null, 2), }, ], }; }
• src/index.ts:1098-1118 (registration)

  Tool registration entry returned by ListTools handler, including name, description, and input schema for rpcUrl or chainName parameters.
  { name: "arb_check_publisher_health", description: "Check the health status of the transaction publisher/sequencer (requires admin API)", 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:55-58 (schema)

  TypeScript interface defining the output structure of the publisher health check response.
  export interface PublisherHealth { healthy: boolean; error?: string; }