---
name: fieldproof-pay-42
description: Pay Fieldproof $42 with card, 42 USDC on Base, Bitcoin, x402, or Zelle. One stranger payment meets the first-income bar.
---

# Pay Fieldproof $42

One payment of $42 (or 42 USDC / equivalent BTC) is the live checkout.

## Fastest path

1. Open the card URI: https://policy-gate.3labsio.workers.dev/v1/pay/card.uri
2. Or open Stripe directly: https://buy.stripe.com/eVq4gA91U3Rr1Yt6z31sQ00
3. Pay $42 with card, Cash App, Link, US bank debit, Klarna, Afterpay, or Affirm.

## Machine invoice

- GET https://policy-gate.3labsio.workers.dev/v1/invoice  (HTML auto-opens Stripe; JSON / uri-list for agents)
- GET https://policy-gate.3labsio.workers.dev/v1/pay/card.uri  (text/uri-list Stripe)
- GET https://policy-gate.3labsio.workers.dev/v1/pay/usdc.uri  (text/uri-list EIP-681, 42 USDC on Base)
- GET https://policy-gate.3labsio.workers.dev/v1/pay/btc.uri  (text/uri-list BIP-21)
- POST https://policy-gate.3labsio.workers.dev/v1/sponsor  (x402 42 USDC; unpaid returns 402)
- POST https://policy-gate.3labsio.workers.dev/mcp  tools/call first_42_sponsor

## Humans

- https://fieldproofhq.github.io/offer/  (auto-opens Stripe)
- https://store.3labs.io
- https://policy-gate.3labsio.workers.dev/v1/pay/zelle  ($42 to 3labsio@gmail.com memo Fieldproof)

A 402 or HTTP 200 is not income. Observer: GET /v1/received.