YNAB MCP Server

Instructions

Implementation Reference

• src/index.ts:325-329 (handler)

  Handles the "list_accounts" tool call by validating input with BudgetIdSchema and invoking the YNABClient.listAccounts method.

  case "list_accounts": {
    const { budget_id } = BudgetIdSchema.parse(args);
    result = await client.listAccounts(budget_id);
    break;
  }

• src/index.ts:116-118 (schema)

  Zod schema used to validate the budget_id input parameter for the list_accounts tool.

  const BudgetIdSchema = z.object({
    budget_id: z.string().describe("The budget ID (use 'last-used' for most recent)"),
  });

• src/index.ts:171-181 (registration)

  Registers the "list_accounts" tool with its metadata for the MCP list_tools request.

  {
    name: "list_accounts",
    description: "Get all accounts for a budget. Returns account names, types, balances, and status.",
    inputSchema: {
      type: "object" as const,
      properties: {
        budget_id: { type: "string", description: "The budget ID" },
      },
      required: ["budget_id"],
    },
  },

• src/index.ts:45-47 (helper)

  YNABClient helper method that fetches the list of accounts via the YNAB API for the given budget.

  async listAccounts(budgetId: string) {
    return this.request<{ accounts: any[] }>(`/budgets/${budgetId}/accounts`);
  }