Grove's MCP Server for Pocket Network

Instructions

Implementation Reference

• src/handlers/blockchain-handlers.ts:62-88 (registration)

  Registers the 'call_rpc_method' MCP tool including name, description, and input schema definition.
  { name: 'call_rpc_method', description: 'Call a JSON-RPC method on a specific blockchain service', inputSchema: { type: 'object', properties: { blockchain: { type: 'string', description: 'Blockchain name (e.g., "ethereum", "polygon")', }, method: { type: 'string', description: 'RPC method name (e.g., "eth_blockNumber", "eth_getBalance")', }, params: { type: 'array', description: 'Array of parameters for the RPC method', }, network: { type: 'string', enum: ['mainnet', 'testnet'], description: 'Network type (defaults to mainnet)', }, }, required: ['blockchain', 'method'], }, },
• src/handlers/blockchain-handlers.ts:202-250 (handler)

  Executes the 'call_rpc_method' tool: performs safety validation, retrieves the appropriate blockchain service, calls the underlying callRPCMethod, and returns formatted result.
  case 'call_rpc_method': { const blockchain = args?.blockchain as string; const method = args?.method as string; const params = (args?.params as any[]) || []; const network = (args?.network as 'mainnet' | 'testnet') || 'mainnet'; // SAFETY CHECK: Validate RPC call before execution const safetyCheck = validateRPCCall(blockchain, method, params); if (!safetyCheck.safe) { return { content: [ { type: 'text', text: `⛔ UNSAFE RPC CALL BLOCKED\n\n` + `Reason: ${safetyCheck.reason}\n\n` + `Suggestion: ${safetyCheck.suggestion}\n\n` + `This protection prevents session crashes from large responses.`, }, ], isError: true, }; } const service = blockchainService.getServiceByBlockchain(blockchain, network); if (!service) { return { content: [ { type: 'text', text: `Blockchain service not found: ${blockchain} (${network})`, }, ], isError: true, }; } const result = await blockchainService.callRPCMethod(service.id, method, params); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], isError: !result.success, }; }
• src/services/blockchain-service.ts:153-248 (helper)

  Core helper function implementing the RPC method call: sends JSON-RPC POST request to the service endpoint, handles HTTP and JSON-RPC errors comprehensively, and returns structured EndpointResponse.
  async callRPCMethod( serviceId: string, method: string, params: any[] = [] ): Promise<EndpointResponse> { const service = this.getServiceById(serviceId); if (!service) { return { success: false, error: `Service not found: ${serviceId}`, }; } const rpcUrl = service.rpcUrl; try { const response = await fetch(rpcUrl, { method: 'POST', headers: { 'Content-Type': 'application/json', }, body: JSON.stringify({ jsonrpc: '2.0', method, params, id: 1, }), }); // Handle HTTP errors (rate limiting, server errors, etc.) if (!response.ok) { const errorText = await response.text().catch(() => 'Unable to read error response'); let errorMessage = `HTTP ${response.status}: ${response.statusText}`; // Common HTTP error interpretations if (response.status === 429) { errorMessage = `Rate limit exceeded (HTTP 429). The endpoint may be experiencing high traffic.`; } else if (response.status === 503) { errorMessage = `Service temporarily unavailable (HTTP 503). The endpoint may be overloaded.`; } else if (response.status >= 500) { errorMessage = `Server error (HTTP ${response.status}). The RPC endpoint encountered an internal error.`; } return { success: false, error: errorMessage, data: { httpStatus: response.status, httpStatusText: response.statusText, responseBody: errorText.substring(0, 500), // Limit error body size }, metadata: { timestamp: new Date().toISOString(), endpoint: rpcUrl, }, }; } const data = await response.json(); // Handle JSON-RPC errors if (data.error) { return { success: false, error: data.error.message || 'RPC error', data: data.error, metadata: { timestamp: new Date().toISOString(), endpoint: rpcUrl, }, }; } return { success: true, data: data.result, metadata: { timestamp: new Date().toISOString(), endpoint: rpcUrl, }, }; } catch (error) { return { success: false, error: error instanceof Error ? error.message : 'Unknown error', data: { errorType: error instanceof Error ? error.constructor.name : 'UnknownError', errorStack: error instanceof Error ? error.stack : undefined, }, metadata: { timestamp: new Date().toISOString(), endpoint: rpcUrl, }, }; } }