Function isAccessTokenAlreadyUsed

isAccessTokenAlreadyUsed(error: unknown): boolean
Whether an error is the backend refusing a second settlement of the same single-use token.

The one correct response is to mint a new token — a retry that replays the same token fails identically forever. Never treat this as a transient settlement failure.
Parameters
- error: unknown
  Any thrown value; typically a PaymentsError from payments.facilitator.settlePermissions
Returns boolean
Example
```
try {
  await payments.facilitator.settlePermissions({ paymentRequired, x402AccessToken })
} catch (error) {
  if (isAccessTokenAlreadyUsed(error)) {
    // Re-mint, do not replay.
  }
  throw error
}
```
- Defined in src/x402/token-version.ts:128