> ## 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.

# upgrade_plan

> Start an upgrade to a paid Agentcard plan

Starts a paid-plan upgrade to Basic ($15/mo, 15 cards/month, up to $500 per card) or Pro ($100/mo, 50 cards/month, up to $1,000 per card). Use it only when the user explicitly wants to upgrade, and confirm the result afterwards with `get_plan`.

## Parameters

| Parameter | Type   | Required | Description                                                      |
| --------- | ------ | -------- | ---------------------------------------------------------------- |
| `plan`    | string | No       | Which plan to upgrade to: `basic` or `pro`. Defaults to `basic`. |

## Returns

Usually a Stripe Checkout URL the user must open in their browser to complete payment (`status: "checkout_required"`); the plan updates automatically once they finish. If the user is already on a paid plan, the subscription is switched in place with proration and no checkout is needed (`status: "swapped"`). Other outcomes are `already_on_plan`, `waitlisted`, `unavailable`, and `checkout_failed`, each with a clear message to relay.

## Example

```json theme={null}
{ "name": "upgrade_plan", "arguments": { "plan": "pro" } }
```