YNAB MCP Server

Instructions

Implementation Reference

• src/index.ts:94-96 (handler)

  The core handler function in YNABClient that fetches the specific transaction from the YNAB API using the provided budgetId and transactionId.

  async getTransaction(budgetId: string, transactionId: string) {
    return this.request<{ transaction: any }>(`/budgets/${budgetId}/transactions/${transactionId}`);
  }

• src/index.ts:139-142 (schema)

  Zod schema used for input validation of budget_id and transaction_id parameters.

  const TransactionSchema = z.object({
    budget_id: z.string().describe("The budget ID"),
    transaction_id: z.string().describe("The transaction ID"),
  });

• src/index.ts:233-244 (registration)

  Tool registration in the tools array, defining name, description, and input schema for MCP server.

  {
    name: "get_transaction",
    description: "Get detailed information about a specific transaction.",
    inputSchema: {
      type: "object" as const,
      properties: {
        budget_id: { type: "string", description: "The budget ID" },
        transaction_id: { type: "string", description: "The transaction ID" },
      },
      required: ["budget_id", "transaction_id"],
    },
  },

• src/index.ts:361-365 (handler)

  Dispatch handler in the main CallToolRequestSchema handler that validates args and invokes the getTransaction method.

  case "get_transaction": {
    const { budget_id, transaction_id } = TransactionSchema.parse(args);
    result = await client.getTransaction(budget_id, transaction_id);
    break;
  }