We break your paywall
before the market does.
Real-money x402 testing and integration from the team that runs a production x402 gateway on Base mainnet.
Pick your exposure.
Start with the audit. Most merchants do. It costs $500, takes three days, and the full amount credits toward a sprint.
x402 Paywall Audit
We pay you real money and watch what breaks.
- Real USDC settles against up to 3 of your endpoints
- The six-point failure checklist, run live
- Written findings memo with BaseScan transaction proof
- Credits 100% toward an Integration Sprint within 30 days
x402 Integration Sprint
Your API accepting USDC on Base, verified with real settles before handoff.
- 402 envelopes on your endpoints
- Verify and settle through the Coinbase CDP facilitator
- Replay protection, plus v1 and v2 envelope handling
- Verified with real external settles before we hand it over
- Two weeks of post-launch questions included
Sentinel Monitoring
Your paywall gets probed with real money so you find out before your buyers do.
- Scheduled real-money canary settles against your paywall
- Hourly liveness probes
- Price and payTo drift alerts
- Weekly report with on-chain proof
- Sold as the follow-on to an audit
The failure checklist.
Six ways x402 paywalls fail in the wild. We have hit every one of them with real money. Every audit runs all six against your endpoints.
Settle-before-validate ordering
We found a live merchant that charges the buyer before validating the request. Every malformed call costs them money.
v1 vs v2 envelope shapes
4 of 18 merchants we probed still serve maxAmountRequired. Buyers on the other shape silently fail.
Replay protection
Nonce plus payer must be enforced. We test it with a real duplicate.
GET with body
Some load balancers reject it before your app ever sees the request.
Bot blocks
Default client user agents trip Cloudflare rules and turn paying agents away.
Dead listings
21.5% of cataloged x402 endpoints are dead. Yours might be listed somewhere you forgot.
We eat our own cooking.
Our own x402 gateway serves live traffic on Base mainnet through the Coinbase CDP facilitator. We debug the same failures we test you for.
We checked the liveness of all 573 cataloged x402 services. We know what dead looks like, and how often it happens.
coinbase/x402 PR #132. The public catalog at autx.ai/x402-services.json. SDKs on PyPI and npm. No invented clients, no testimonials. Verify all of it yourself.
Find out what breaks.
Before your buyers do.
Email [email protected] with the subject "Audit" and your endpoint URLs. We reply within one business day with a start date.
AUTX DAO LLC, Wyoming. Payment in USD or USDC.