API keys vs pay-per-use crypto payments for developer APIs?

While building HashProof I ran into an interesting dilemma.

Most developer APIs use API keys and traditional billing (Stripe, subscriptions, etc).

But I'm experimenting with a different approach: using x402 so agents or developers can pay per request using USDC.

That makes things like:

• no account creation

• no API keys

• no subscriptions

• pure pay-per-use

But I'm wondering if this might be too unfamiliar for most developers.

Curious to hear from builders:

If you were integrating an API, would you prefer:

A) Traditional API keys + billing

B) Pay-per-use with crypto (no account)