> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agentcard.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# buy_set_budget

> Set a spending budget that the spend gate enforces before any checkout creates a card.

Connect to `https://mcp.agentcard.sh/mcp` with the **user's connection token** (or a `buy_token` for org-owned accounts).

**Behavior:** idempotent.

<Note>Not in the default `tools/list`. It is still callable by exact name, and appears when the client sends the `x-expert-tools: 1` header.</Note>

## What it does

Set a spending budget that the spend gate enforces before any checkout creates a card. Period is daily | weekly | monthly | total.

## Inputs

| Field                      | Type                                             | Description                                 |
| -------------------------- | ------------------------------------------------ | ------------------------------------------- |
| `period` *(required)*      | string: `daily` · `weekly` · `monthly` · `total` |                                             |
| `limit_cents` *(required)* | number                                           | budget cap in cents                         |
| `timezone`                 | string                                           | IANA tz for window boundaries (default UTC) |

## Returns

None.

## Example call

```json theme={null}
{
  "tool": "buy_set_budget",
  "arguments": {
    "period": "\u2026",
    "limit_cents": "\u2026"
  }
}
```